Is Chocolate Milk a Good Recovery Aide for Swimmers?

Take Home Points on Is Chocolate Milk a Good Recovery Aide for Swimmers?
  1. Milk has a beneficial protein to carbohydrate ratio for aiding recovery.
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[Editors Note: A recent research article [which is available for free] was just released about milk compared to Casein].

What is up with chocolate milk? Is it a good recovery aide? If so, how much does a 120
high school female need after a workout? What other supplements/nutrients are helpful after practice? Thanks!

Short Answer: Yes.
Extended Answer: Chocolate Milk has been touted as a performance enhancer/ recovery aid largely throughout the sports community since at least the new millennium.  The basis in this comes from the idea that chocolate milk has an ideal ratio of carbs to protein, which helps deliver protein to damaged muscle tissue.  This thought is based around the fact that the sugary additives in the chocolate milk create a higher insulin response (which is the body’s nutrient ‘carrier’).  In theory this is great, higher carb levels lead to higher protein/nutrient content being shuttled to skeletal muscle to promote healing—so far so good.

One area that is overlooked in this debate, however, is the breakdown of types of protein in milk.  The two major types of protein are casein, commonly found in supplements which advertise ‘time-released formulas’ or ‘overnight recovery aide’, as well as the more known whey protein.  Whey is the type of protein which receives the majority of the media hype, as well comprises most protein supplements.  You may be able to tell a whey protein product from the phrases on its package saying things similar to ‘rapidly digesting’ or things of this nature. 

One idea recent scientific evidence is pointing to, is that types of protein, and release patterns may not relate to recovery as significantly as we previously thought.  But one other benefits of whey protein is that is highly insulinogenic; this means that the whey protein in itself releases a large surge of this insulin that we’ve been talking so much about (whey protein causes about a 1:1 spike in insulin when compared to simple sugars).  So what does this mean?  The current idea in nutrition is that insulin caused by the sugary additives in the chocolate milk creates releases a surge in insulin, which can then shuttle the protein to skeletal muscle which has been damaged by vigorous activity (in this case a swimming practice or meet), but this new research suggests that whey releases enough insulin itself to do the job of the sugar, making the sugary additives obsolete.

So as of this point in the article, it seems like I’m making the case for regular milk, over chocolate—but both of which, have their place.  While the caloric reduction, as well as the insulinogenic benefits from the whey may seem to do the job in white milk, the extra calories of the sugar might be more beneficial for athletes (in this recovery setting).  Because the body uses primarily muscle glycogen (sugar stored in the muscle) during intense swimming bouts, restoring this as soon as possible after exercise is important, and chocolate milk just happens to be a convenient way to do so. 

For amount of chocolate milk, a 12-16 oz. container, which you may find at the store is perfect.  You don’t really need to worry about specific volumes, or calorie counting, until your diet is already extremely regimented.  Of course there is the issue of lactose intolerance, which is extremely common, and grows more prevalent as we age.  Under this circumstance, obviously it varies by the individual.  Many can get away with a single serving of milk, but others cannot.  If you experience gastrointestinal upset from milk, it should be avoided; however, if you are capable of digesting this with no adverse effects, it can be very beneficial.

One thing I find very commonly with athletes is that, when they pick a chocolate milk product, they go for the low fat.  This is also not what you want, as I said before, this post workout period is a great time to consume more calories to recover.  Fat is no exception to this rule.  For years fat has been vilified as a main cause of heart disease, inflammation, and a laundry list of other problems, but fat appears to just be a scapegoat.  Fats, including some saturated fats (like the kinds in milk), are extremely beneficial for hormone regulation, and therefore recovery. 

So when it comes to choosing between milk for recovery, I suggest full-fat chocolate milk.  If you are however, looking to watch your calorie intake, I first suggest eliminating the extra calories in the form of artificial sweeteners in the chocolate milk—so go with white, whole milk, in this situation.  And although you may be gaining some extra calories from this fat initially, you will be recovering better, and feel more satiated from the fat content for longer, making it easier to decline other foods later on.

As far as other supplements are concerned, none work as well as whole, minimally processed foods.  As I do understand your diet may not always be ideal, I do suggest a complete multivitamin taken daily.  I know in this specific case we’re talking about a 120 lb. high school female, so I would just suggest maintaining a high level of protein intake (making sure to get a full serving of protein-rich food per meal), which can be a large problem with the young, female demographic.

As far as other nutrients, vitamins, minerals, and the fiber you need will come naturally with a healthy diet. And as I stated earlier, we can’t really vilify anything, a good balance of healthy fats, proteins, and carbohydrates will be a huge key in injury prevention, recovery, well-being, and your athletic success.

Written by John Matulevich a powerlifting world record holder in multiple lifts and weight classes, as well as a Head D-2 Strength Coach, and previously a nationally ranked college athlete. His concentrations are in sports performance, powerlifting, and weight training for swimming. To learn more about how John trains his athletes, check his Twitter page: @John_Matulevich. He can also be reached at with inquiries.

Friday Interview: Dr. Vassilis Mougios Discuses Nutrition for Swimmers

1. Please introduce yourself to the readers (how you started in the profession, education, credentials, experience, etc.). 

I am Professor of Exercise Biochemistry at the School of Physical Education and Sport Science at Thessaloniki, the Aristotle University of Thessaloniki (AUTh), Greece. I am a chemist by training and did my PhD in muscle biochemistry at the University of Illinois at Chicago. I have been a faculty at the AUTh for 25 years, teaching both undergraduate and graduate students, mentoring, doing research on exercise biochemistry and physiology, as well as writing scientific papers and books.

2. You recently published numerous articles on swimming and nutrition. What do we know about swimmers and their nutrition? 
Research on swimmers’ nutrition has yielded many interesting findings. Swimmers are, in several cases, not meeting their macronutrient requirements (for example, excessive intake of fats in place of carbohydrates) or micronutrient needs (for example, suboptimal intake of iron). Nevertheless, energy intake, as a whole, seems to balance energy expenditure. Another finding is that swimmers use dietary supplements that are frequently excessive and unnecessary. 

3. What are some myths about swimmers’ nutrition?
Extremely low-energy, or crash, diets, aiming at rapidly reducing body weight, are unsafe and usually accompanied by a drop in performance. Energy intake should just be individually tailored to meet energy demands and nutrient needs of the swimmer during each training phase. If weight loss is needed or desired, energy balance should be moderately negative so as not to compromise health and hamper performance.

Dietary supplement use among swimmers is, in many cases, scientifically unjustified. Swimmers should not give in to nutritional trends before seeking advice from a qualified professional.

4. How can swimmers nutrition be improved? 
Nutritional education can help swimmers implement good dietary habits, which, in turn will help them meet their nutritional needs. The need for nutritional education targeted at athletes, their parents and coaches is often highlighted in the literature. Dietary analysis and evaluation, along with hematologic and biochemical testing, as well as anthropometric evaluation, are indispensable in order to estimate individual needs and pinpoint possible inadequacies. Regular re-evaluation should also be in order.

As a general guideline, swimmers should incorporate a great variety of foods (such as vegetables, fruits, pasta, red and white meat, dairy products, cereals and fluids) in a carefully planned daily schedule (encompassing 5-6 meals) and adapt this schedule to the particular demands of training phase and goals.

5. Many athletes are attempting a Low Carb High Fat diet, what do you think of this idea for sprint and distance swimmers? 
Such diets seem improper for swimmers from both a health and performance standpoint. Surely, sprinters do not rely on fats for success in their events. Distance swimmers use more fats (compared to sprinters), mostly during prolonged training sessions; however, these too draw more energy from carbohydrates than fats. Low carbohydrate availability, although it may facilitate some training adaptations in some cases, has not been tested in a competitive environment, more so in swimmers. Low Carb High Fat diets can have negative effects on performance, recovery, body mass, body composition, immune system and lipidemic profile of swimmers.

6. If an athlete could afford any testing or consulting on nutrition, what should they do?
They should have their diet analyzed in conjunction with hematologic/biochemical testing as a first step towards better nutrition. A qualified professional could use this information to assess possible inadequacies and suggest corrective measures. Such procedure can improve training adaptations, recovery, performance and the overall health of swimmers.

7. What supplements do you think are helpful for swimmers?
Creatine can enhance the yields of power training and performance in events relying on the ATP-phosphocreatine system. Sodium bicarbonate has been found to enhance performance in events relying on the anaerobic breakdown of carbohydrates. Caffeine has been found to enhance performance in events lasting longer than 4 minutes by decreasing the rate of perceived exertion. Nitrates have been found to increase exercise economy, although data on swimming performance are scarce. Sports drinks (containing carbohydrates and electrolytes) are suggested during training and prolonged events to prevent carbohydrate depletion and dehydration. Micronutrient (such as iron and magnesium) or macronutrient supplements (such as carbohydrate and protein) can be helpful in cases of inadequate or imbalanced nutrition. Supplements should only be used under expert supervision and should be tailored to the specific needs of the swimmer. Always bear in mind that supplements are, well, supplements; they can’t substitute for a well-balanced diet.

8. How should supplement use be improved in swimming?
Primarily, through nutritional education of swimmers, their parents, and coaches. All these should be thoroughly informed about best nutritional practices, optimal food selection, as well as the pros and cons of the various supplements on the basis of available scientific evidence. Second, through the implementation of dietary analysis and hematologic/biochemical testing in order for inadequacies to be spotted and remedied. An expert on sport nutrition should always be the one to recommend supplements and the way they should be used. Adverse health effects or doping outcomes are a real danger of sloppy supplement use.

9. If someone is on a budget, what are the easiest nutritional tips for elite swimming performance?
A wide variety of foods can improve a swimmer’s dietary status and performance. Foods that are inexpensive in most countries can easily supply swimmers with all the nutrients they need. Fruits and vegetables are rich in micronutrients; pasta, rice and potatoes are rich in carbohydrates; chicken and dairy products are rich in proteins, minerals, and vitamins. All these foods are rather low-cost. Use the highest variety possible; it’s the best recipe against nutrient deficiency and the need for expensive supplements.

10. What are some emerging ideas/hypotheses about elite athlete nutrition? 
Nutrient timing, especially around training sessions or competition, seems to be a promising concept regarding swimmers’ nutrition. Optimal energy supply, recovery, and adaptations, all leading to increased performance, might be achieved through proper timing and control of dietary intakes.

11. What research or projects are you currently working on or should we look from you in the future?
Over the past few years, our attention has been attracted by a rather overlooked biological specimen in exercise science: urine. Our data from running and swimming studies show that urine possesses certain advantages over blood in terms of the information they provide about exercise metabolism. We plan to publish such information from swimmers’ urine analyses in the very near future. 

Swimming has also been an attractive exercise model to apply on laboratory animals. We are currently examining the effects of life-long exercise (daily swimming) on metabolism and frailty status of rats. Naturally, it would be preferable to conduct such a study on humans but this would take a lifetime (literally). In contrast, it’s easier to do it with rats that live about two years. Hopefully, the results of this study will be applicable to us humans.

Multivitamins for Swimmers? Do They Work?

Take Home Points on Multivitamins for Swimmers? Do They Work? 

  1. Multivitamin supplementation for 7 - 8 months does not increase performance.
  2. Coaches should reconsider their travel and team meals, stressing healthy options for long-term nutritional health. 

Having minimal mineral and vitamin levels is likely a prerequisite for elite performance. Many feel athletes undergoing heavy training volumes and intensities require different vitamin/mineral consumption for maximal performance. In fact, some feel it is difficult for many to maintain certain mineral and vitamin levels due to the demands of training. 

Combine this with other factors which alter vitamin/mineral levels like age, sex, season, and vitamin/mineral supplementation seems imperative.

Telford (1992) split eighty-two subjects (23 swimmers, 24 gymnasts, 21 basketball players, 14 rowers; M=49, F=32; ~18.95 years) into an experimental or control group. Both groups were supplemented with iron (ferrous sulphate) if their plasma ferritin concentrations fell below 30 ng/ml (measured throughout the study). 

The experimental groups took a daily vitamin and mineral supplementation tablets. The controls received a placebo. All participants received nutritional education. Performance tests were taken before and after the 8 week intervention. 

Vitamin and Mineral Supplementation on Body Composition

The results noted similar nutrient intake between groups. The basketball players had a significant increase in body weight for the experimental protocol. There was also a significant increase in skinfold for the supplement group of basketball players. Iron intake dropped below 100% in the control group of gymnasts. 

Vitamin and Mineral Supplementation on Performance

No significant effects of performance were measured in the swimmers, gymnasts or rowers. There was another significant improvement in vertical jump in the supplement group of basketball players. 

The diets in these athletes reached the recommended dietary intake (RDIs) for vitamins and minerals). In athletes meeting the minimum RDI did not alter performance. The weight gain in the basketball players is surprising, potentially by increasing the B6 status and increasing power development.

Supplementation in athletes already reaching RDIs of vitamins and minerals does not improve performance. However, many will question if RDI is the best method for measuring nutrient adequacy. Certainly, many methods of measuring micronutrients has improved since 1992, requiring more recent review. Also, many will agree the nutrient profile has greatly changed for swimmers (and the general population since 1992). 

No matter if achieving RDIs of vitamins and minerals occurs, coaches should strive for adequate nutrition for each of their swimmers. Also, blindly supplementing is likely a waste of money. Instead of supplementation, set a healthy nutritional plan for their future. Too often teams ignore nutrition, especially during travel, impairing their nutrition for an entire life! 

Coaches quit stressing supplement intake and stress a well-rounded diet! This implementation may not improve performance, but can increase health and weight management for a lifetime! Remember, children's brains are highly plastic, ensure you're molding them correctly!

  1. Telford RD, Catchpole EA, Deakin V, Hahn AG, Plank AW. The effect of 7 to 8 months of vitamin/mineral supplementation on athletic performance. Int J Sport Nutr. 1992 Jun;2(2):135-53.
By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the owner of COR, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

Excess Protein Intake Does Not Increase Muscle Mass

Take Home Points on Excess Protein Intake Does Not Increase Muscle Mass

  1. Excess protein intake (4.4 g/kg) does not alter body composition
Swimmers, like all athletes and fitness enthusiast commonly consume protein powder or
copious amounts of protein. Some feel this high volume is damaging on the kidneys, but does it help build muscle and increase force production potential for swimmers? Also, what is the ideal protein intake for improvement?

Protein is an important macronutrient for positive changes in body composition. Previous studies have suggested that protein intakes in the range of 1.2-2.0 grams per kilogram (kg) body weight per day (g/kg/d) are needed in active individuals. In contrast, the US recommended daily allowance (RDA) for protein is 0.8 g/kg/d (Antonio 2014). The average amount of protein ingested for adults daily is ~1.0 g/kg ideal body weight. The average US adult consumes slightly more than the RDA; however, this level is inadequate for athletes or active individuals who engage in exercise/sport training for several hours per week (Antonio 2014). Consuming more than the RDA can be considered a ‘high’ intake of protein. Many a high protein diet greater than 15-16% of total energy intake, intakes greater than the RDA or perhaps anything that exceeds 35% of total energy intake. Studies had differed to what constitutes a ‘high’ protein diet. We would argue that using percentages as a means of defining ‘low’ or ‘high’ protein intakes is misleading. If one were to consume the low calorie diet (ex. 1000 kcal/d), a protein intake of 36% (of total kcals) would be 90 grams; in contrast, it would be 180 grams on a 2000 kcal/d (Antonio 2014).  It is best to measure protein intake per unit body weight instead of as a percentage of total energy.

Antonio (2014) investigated the effects of a very high protein diet (4.4 g/kg/d) on body
composition in resistance-trained men and women. Thirty healthy resistance-trained individuals participated in this study (age: 24.1 yr; height: 171.4 cm; weight: 73.3 kg). Subjects were randomly assigned to one of the following groups: Control (CON) or high protein (HP). The CON group was instructed to maintain the same training and dietary habits over the course of the 8 week study. The HP group was instructed to consume 4.4 grams of protein per kg body weight daily. They were also instructed to maintain the same training and dietary habits (e.g. maintain the same fat and carbohydrate intake). Body composition (Bod Pod®), training volume (i.e. volume load), and food intake were determined at baseline and over the 8 week treatment period. The HP group consumed significantly more protein and calories pre vs post. Furthermore, the HP group consumed significantly more protein and calories than the CON. The HP group consumed on average 307 grams of protein compared to 138 in the CON. When expressed per unit body weight, the HP group consumed 4.4 g/kg/d of protein versus 1.8 ± 0.4 g/kg/d in the CON. There were no changes in training volume for either group. There were no significant changes over time or between groups for body weight, fat mass, fat free mass, or percent body fat. Consuming 5.5 times the recommended daily allowance of protein has no effect on body composition in resistance-trained individuals who otherwise maintain the same training regimen. This is the first interventional study to demonstrate that consuming a hypercaloric high protein diet does not result in an increase in body fat.

This is the first study in resistance-trained individuals which demonstrates that a hypercaloric high protein diet does alter body composition. Previous studies investigating overfeeding showed gains in body weight, fat mass and lean body mass. Those studies used non-exercise-trained individuals that were consuming a lower protein diet. The subjects in the current study did not alter their training. It would be interesting to see if a high protein diet concurrent with heavy swimming or current resistance training and swimming would alter swimming performance and body composition. In the mean time, excess protein intake is not likely beneficial for swimmers, or any exerciser, so lay off the excessive protein and simply consume ~1.2 - 1.7 g/kg/d of protein.
  1. Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr. 2014 May 12;11:19.

By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the owner of COR, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

Friday Interview: Aaron Hermann Discusses Doping in Sports

1. Please introduce yourself to the readers (how you started in the profession,
education, credentials, experience, etc.).
My interest in sports from a professional perspective began when I studied a course in Sports Law during my Law Masters. The issues presented, particularly relating to doping seem both interesting and concerning simultaneously. I was especially interested in the aspects of fairness, ethics and equality and how diplomacy can aid in helping to ensure sports remain sustainable. I have higher degrees in Law, International Law, Commerce, Diplomacy and Arbitration and currently working toward completing my PhD. I have been teaching at university in the areas of Business Law and Management for the last 7 years.

2. You recently published an article on performance of doping and non-doping 100-m runners. What research do we know about doping?
There has been a lot of research done in the area of doping in sport. Much of the research relates to attempts to improve doping detection, from enhancements of older techniques to novel approaches to detection. There is also much work on determining if a particular agent is performance enhancing or not. Others still concern the legal and ethical problems related to the current anti-doping systems and general discussions of reasons for anti-doping. Sociological and historical analyses are also quite common.

3. You mention conflicting evidence on the effects of doping in sports. Is there a reason why we don't have concrete evidence on doping, especially anabolic agents?
This relates to the clandestine nature of doping. Because doping is forbidden, and in many countries a criminal act, the practice is very much underground and so reliable information is difficult to come by. Particularly for athletes, this means that if they want to resort to doping, they would be experimenting with different substances in different ways and as such will have different apparent effects on their performance and health. Academic research is performed on numerous substances, but it is incomplete and simply cannot investigate every agent in existence. Similarly different techniques for investigating agents will inevitably result in differing results.

4. What were the results of you study?
The way doping is practiced, particularly because of the lack of reliable information about the effects of doping and the hidden nature, means that athletes need to experiment. It seems that the ways they are experimenting has random results on performance, and as such the overall performance of doped and non-doped athletes does not differ significantly. This does not mean that all doping is ineffective for performance enhancement, historical examples have shown that scientifically supported and controlled doping does indeed work but rather experimentation has its down sides. Moreover, doping is far more widespread than anti-doping statistics would indicate, it would seem that a larger number of athletes are doping than are being caught.

5. What are some of the theories for doping not improving 100-m performance?
Experimentation; the lack of clear effects of doping agents and which techniques or amounts to use mean that athletes would need to randomly rely somewhat on luck. Especially because of the hidden nature of doping, so athletes simply do not have full knowledge of the effects. Also there are a number of different aspects of sprinting, not just strength, but also reaction time, and so to target many different aspects of performance, many different agents will need to be combined. This could result in any number of unexpected consequences and results to both health and performance.

6. Some will disagree with your suggestions in this paper, as some feel doping obviously makes 100-m runners faster (ie Ben Johnson), what do you saw to these thoughts?
There is definitely some evidence that shows that doping does work for performance enhancement, not just in sprinting but also cycling, shot-put and a number of other sports. Historical evidence, such as with East Germany, demonstrate the enhancement possibilities available. The problem that exists in some sports and with some athletes is the lack of clear information and support. Situations where it is still scientifically supported would probably result in positive enhancement of results. But if athletes are randomly experimenting, then the effects will be unknown. This would, however, indicate that athletes in some cases are still being supported by unethical sports scientists or medical practitioners, and that anti-doping legislation is less effective than desired.

7. In your study, you also say these results may be very sport specific, can you speculate about doping in swimming?
If you look at the WADA laboratory statistics for aquatics, it can be seen that the adverse analytical findings of doping in aquatics are a little bit lower than athletics. To think that doping is not happening in any sport is unreasonable, it no doubt still occurs. Not all athletes are willing to compete on a level playing field and will take anything to get the advantage. There have been recent scandals in Australia with swimming and the use of sleeping pills, whilst not in the same category as doping; some may say that because they are being abused to help athletes sleep it may still constitute an unfair act. So it is difficult to know exactly the levels, but it no doubt still occurs.

8. Do you think doping regulations or monitoring could be improved, if so how?
Yes anti-doping policies need considerable work. The current system revolves around chemical testing and punishment. There is considerable evidence out there that the chemical testing is either simply not detecting everything or athletes are just adjusting their doping regimes to accommodate the testing realities. Most athletes are not stupid and so are quite capable of learning and changing their practices to avoid testing positive. Similarly, many of the punishments are not effective, either because they fail to target the cost-benefit ratio (the benefits of doping outweigh the punishments) or they fail to address the true cause of the doping. There are numerous realities of the world of sports, expectations by spectators, managers and coaches all put pressure on the athletes to perform at a level that, in some cases, is unstainable without resorting to other techniques, and some may resort to doping to help cope. Changes to the anti-doping systems need to address the problems and causes triggering doping, not just punishment after the doping scandal comes to life. In essence less stick more carrot. Athletes’ perspectives and psychologies need change, there needs to be social changes in the way sports operate and athletes make decisions. Athletes need to decide themselves not to dope, policies should not just try to scare them into not doping.

9. What research or projects are you currently working on or should we look from you in the future?
I am currently looking at alternatives to the current anti-doping systems, that target not just punishment but rather social changes to the sporting system and the ways in which sports are viewed. For example investigations into the ethical, social and psychological aspects of anti-doping from all stakeholders in sport. More generally new approaches to prevent doping scandals before they occur.

Low Bone Mineral Density in Swimmers is Caused by Magnesium Deficiency?

Take Home Points on Low Bone Mineral Density in Swimmers is Caused by Magnesium Deficiency?

  1. Low magnesium levels predicted low bone mineral density and lean soft tissue in elite Portuguese swimmers
  2. Adding 100 mg of magnesium a day improved these levels
Nutrient and supplements are a huge market for athletes. Swimmers (the small market we are) even have our own supplement line targeting swimmers. Now, proper nutrition and a well-balanced diet are essential for success, but how do you know what to take and how much? 

Individualized nutritional and supplement programs are ideal, as everyone consumes and metabolizes food differently. If looking for the top advice, have some blood work, then consult a physician or nutritionist on your deficiencies. Now, which blood markers influence performance is not well understood (vitamin D deficiencies are often low, but may not influence performance), but adequate nutrient levels likely influence long-term health.

In swimmers, bone mass and muscle mass are important considerations due to the lack of joint loading. Magnesium (Mg) appears influential on bone mineral density (BMD). It is estimated that 1300 g of calcium, 14 g of Mg and 60 g of phosphorus in bones of a 70 kg human (154 – pound human) (Synder 1975). Therefore, understanding the influence of Mg on bone and lean body mass an essential consideration for athletes.

Matias  (2012) had seventeen elite swimmers (M=8, F=9; ~16.6 years; Sprinters=6, Middle distance=9, Distance=3) from Lisbon with at least:
1)    Minimum period of activity of approximately six years
2)    > 10 hours training per week
3)    Negative test outcomes for performance enhancing drugs
4)    Not taking any medications or dietary supplements

All the swimmers underwent body composition testing (BOD POD), dual energy x-ray absorptiometry (DEXA), recorded energy and nutrients for a seven day period.

Males had significantly lower bone mineral density than normative values. Mg, P, and vitamin D intake were significantly lower than the recommended daily allowances. Mg values were a predictor of lower bone mineral density. There was also a direct correlation between bone mineral density and lean soft tissue (muscle mass).

Magnesium and Bone Mineral Density

Mg correlates with BMD and lean soft tissue (LST). In fact, this study suggests that Mg intake explains an additional 24% of BMD than LST by itself.

If these calculations are accurate, adding 100 mg of Mg a day would increase BMD by 0.259 g/cm2, providing normative values.

Practical Implication for Swimmers

Young swimmers should consume foods high in minerals. If low in magnesium, consider adding dark leafy green vegetables and nuts into the diet. However, extrapolating this data blinding is a flaw, as individual nutrition and guidelines are mandatory for cost efficient, effective nutritional and supplement recommendations.


  1. Snyder WS, Cook MJ, Nasset ES, Karhausen LR, Howells PG, Tipton IH. Report of the Task Group on Reference Man: a report. Oxford:Pergamon Press, 1975.
  2. Matias CN, Santos DA, Monteiro CP, Vasco AM, Baptista F, Sardinha LB, Laires MJ, Silva AM. Magnesium intake mediates the association between bone mineral density and lean soft tissue in elite swimmers. Magnes Res. 2012 Jul-Sep;25(3):120-5. doi: 10.1684/mrh.2012.0317.

Written by G. John Mullen who received his Doctorate in Physical at University of Southern California (USC) and is a certified strength and conditioning specialist (CSCS). At USC, he was a clinical research assistant performing research on adolescent diabetes, lung adaptations to swimming, and swimming biomechanics. G. John has been featured in Swimming World Magazine, Swimmer Magazine, and the International Society of Swim Coaches Journal. He is currently the owner of COR, providing Physical Therapy, Personal Training, and Swim Lessons to swimmers and athletes of all skills and ages. He is also the creator of the Swimmer's Shoulder SystemSwimming ScienceSwimming Science Research ReviewMobility System and the Swimming Troubleshooting System.

Energy Expenditure in Swimmers

Take Home Message for Energy Expenditure and Swimmers

  1. It is possible to estimate the energy cost of a training session or a race; 
  2. A training session of 3,000m at aerobic capacity pace will expend around 1,100 kcal;
  3. A sub-elite swimmer that races the 400 free in 4:00.00 expends 147 kcal (35g of carbs and 0.32g of fat will be fueled).
It is the Christmas season and it being New Years Eve, people fly back home to be with the loved ones (and have a lot of food), schedule meetings with old friends (over a meal), bond with peers and colleagues (with the excuse of a… exactly …a snack and a drink).  On the flip side, the number, volume and intensity of the training sessions tend to change. So, one concern of most coaches during the holiday season is the swimmers’ food intake and the lack of workout [see Why Swimming Stimulates Appetite?].

Weight depends from the balance between the total energy expenditure and the total energy intake. One loses weight if the expenditure is higher than the intake. Otherwise, if the expenditure is lower than the intake s/he will put some weight.

Total energy expenditure is the sum of the: (i) resting metabolism (i.e, to sustain basic chemical processes and keep the body working); (ii) physical activity (including physical daily routines plus exercise & workout) and; (iii) thermic effect of food (i.e., the energy needed to digest food). Energy can be measured in Joules or calories. Most of us are familiar with the calories as units of measure. One calorie is the quantity of heat needed to raise the temperature of 1 kg (1 L) of water 1°C.

The three major macronutrients are: (i) proteins (it has 4 mkcal per gram); (ii) lipids (9 kcal per gram) and; (iii) carbohydrate (4 kcal per gram). As we can see the carbs are the most energetic nutrient. Table 1 shows the amount of energy stores for an “average” subject with 70 kg and a fat content of 15% of body weight (adapted from Maughan and Burke, 2002). FYI, it is not hard to find swimmers with around 70 kg and 15% of fat mass.

Table 1. Energy stores in the average man (adapted from Maughan and Burke, 2002).

Now let’s bridge all these with competitive swimming. Comparing the energy expenditure for a given speed, front-crawl is the most economical stroke, followed respectively by the backstroke, butterfly stroke and lastly the breaststroke (Barbosa et al., 2006). Please bear in mind that we are comparing the four strokes at the same absolute speed. If we would ask someone to swim at a self-selected speed, i.e. a comfortable speed with a nice and easy technique, things could be slightly different. Since the comfortable speed at breaststroke is lower than butterfly, likewise the energy expenditure would be also lower. That is why non-expert subjects, such as fitness-oriented swimmers are most keen to swimming breaststroke rather than butterfly. In this sense, energy expenditure also depends from the competitive level (Fernandes et al., 2006).

The substrates or macronutrients fueled can be indirectly estimated measuring the carbon dioxide production (VCO2) and the oxygen consumption (VO2) with a metabolic cart. The ratio VCO2/VO2 is termed “respiratory exchange ratio” (RER) and gives an estimation of the amount of energy being fuelled with origin in fats or carbs.

We can learn about the energy needed to complete a training session or even a race knowing the swim speed, the distance and the RER. Having those as input data it is possible to calculate the energy cost. The energy cost is the amount of energy that we expended to swim one meter. I invite you to download the spreadsheet attached [TB1] to this post and play with it. Calculations are based on a description found in the literature (Zamparo and Bonifazi, 2013).

A couple of examples how to put together the calculations and interpret the data.

Training volume: I had a training session of 3,000 meters with the main goal of eliciting the aerobic capacity at front crawl. Sets like 15 x 100m @ 65 seconds. Therefore, I will key-in in the excel sheet (red cells on the top) a speed of 1.54 m/s, a distance of 3,000m and a RER of 0.85. So, the total energy cost of this session was 1,088.55 kcal (blue cells in the middle). Meaning that it was fueled 126.64 grams of carbs and 61.09 grams of fat (blue shaded cells on the bottom).

Swim race: Another example is how much subtracts are fueled in a race. I raced the 400 free with a final time of four minutes sharp (240s, i.e. an average speed of 1.67 m/s). The RER for swim paces close to aerobic power (as happens for swim races that takes around four minutes) according to instructions in the spreadsheet is RER=1.0. In this case, the energy cost of the 400 free race was 146.55 kcal (34.94g of carbs and 0.32g of fat).

I would like to call your attention that this spreadsheet does not substitute the advising of a certificated professional. Only provide us a very rough estimation of the energy fueled during the workout. The energy needed for basal metabolism, physical daily routines and thermic effect of food are not computed. Besides that, after exercise energy expenditure remains high for at least 4 hours (Kuo et al., 2005). Others reported this effect for a longer period of time, up to 24h (LaForgia et al., 2006). The post-exercise expenditure increases mainly the fat consumption (i.e. lipid oxidation). Good news for fitness-oriented people willing to lose weight. They are burning calories not only during the workout but also (at a much lower rate though) a few hours later.

Anyway, if that’s the case, have a safe trip back home, enjoy the meals that brings back memories of your childhood, a merry Christmas and a very happy new year to each and everyone of you! [below is an example of the attached link for the program above].


  1. Barbosa TM, Fernandes RJ, Keskinen KL, Colaço C, Cardoso C, Silva J, Vilas-Boas JP. (2006). Evaluation of the energy expenditure in competitive swimming strokes. Int J Sports Med 27: 894-899
  2. Fernandes RJ, Billat V, Cruz A, Colaço P, Cardoso C, Vilas-Boas JP (2006) Does net energy of swimming affect time to exhaustion at the individual's maximal oxygen consumption velocity? J Sports Med and Phyis Fitness 46: 373-380
  3. Kuo CC, Fattor JA, Henderson GC, Brooks GA. (2005). Lipid oxidation in fit young adults during postexercise recovery. J Appl Physiol 99: 349-356
  4. LaForgia J, Withers RT, Gore C (2006). Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J Sport Sci 24: 1247-1264
  5. Maughan RJ, Burke LM (2002). Sports Nutrition. An IOC Medical Commission Publication. Blackwell Publishing. London
  6. Zamparo P, Bonifazi M (2013). Bioenergetics of cycling sports activities in water. In: Bagchi D, Nair S, Sen CK (eds). Nutrition and enhanced sports performance. pp 143-150. Elsevier. Oxford
Written by Tiago M. Barbosa earned a PhD degree in Sport Sciences and holds a position at the Nanyang Technological University, Singapore.

Does Alcohol Affect Swimming Performance?

    Take Home Points on Alcohol and Swimming Performance

    1. Acute alcohol consumption will likely affect endurance performance in sufficient dosage.
    2. Evidence is unclear with effects on anaerobic performance.
    3. Limited research exists on effects of hangovers.
    4. Post exercise alcohol consumption may impair recovery.
    Alcohol plays a role in many swimmers’ lifestyles, ranging from social drinking to wild weekend parties. Anyone around the sport has heard rumors of Ryan Lochte or Michael Phelps drinking the day before amazing workouts. During the holidays, many people take the opportunity to throw back a few at holiday gatherings. Yet despite the obvious effects that excess alcohol can have on the body, many people are unsure exactly how alcohol may affect athletic performance, especially in the pool.

    “The detrimental effects of alcohol on human physiology have been well documented, adversely influencing neural function, metabolism, cardiovascular physiology, thermoregulation and skeletal muscle myopathy. Remarkably, the downstream effects of alcohol consumption on exercise performance and recovery, has received less attention and as such is not well understood (Vella 2010)". Because the literature does not cover specific effects for swimmers, in this article we must infer conclusions from studies on other populations.

    Not surprisingly, the effects of alcohol may be dose dependent, as Barnes (2010, 2011) completed two separate studies testing alcohol consumption among ten males at 0.5g and 1.0g of ethanol per kg of bodyweight. Subjects in both studies performed 300 maximal eccentric quadriceps contractions under both an alcohol and non-alcohol condition. Though fatigue was noted in all conditions in both studies, the difference between the alcohol condition and the control condition was only significant with the 1.0 g/kg bodyweight study.

    One key area for all athletes is anaerobic performance. Multiple studies have tested alcohol’s effects in this area and have found a limited impact. McNaughton (1985) tested track and field athletes at all distances from 100m through 1500m (equivalent of a 25m to 400m range in swimming) with progressively increasing amounts of alcohol. Alcohol detrimentally affected performance at all distances except the 100m dash, in which performance remained stable!

    In another study, Clarkson (1990) tested ten women performing upper body exercise under alcohol and non-alcohol conditions. Subjects in the alcohol condition consumed the beverage immediately before exercise. Authors studied both groups testing “force generation, muscle stiffness and muscle soreness” but there was no significant difference between the alcohol and nonalcohol conditions for any criterion measure. It was concluded that acute ingestion of alcohol has no effect on several indicators of exercise-induced muscle damage.” One caveat from this study is that acute consumption is not likely to occur (drinking right before practice) in a real-life setting (at least hopefully not!).

    Does Alcohol Affect Endurance Performance? 

    As noted above, the McNaughton study found significant performance deterioration in track athletes from all distances from 200m to 1500m, or similar to the 50m through 400m in the pool. In a more recent study, an acute low dose of alcohol significantly reduced power output among well trained male cyclists. Authors theorized that “cardio-vascular strain and psychobiological mechanisms may explain this decrease of endurance performance (Lecoultre 2009)".

    It is well established on this site that sleep is maybe the most underutilized performance enhancement tool [Sleep Restriction Impairs Swimming Performance]. Unfortunately, alcohol consumption habits may undermine even the best intentions with sleep, and may sabotage an athlete with poor sleep habits. In a study comparing bourbon with vodka consumption among young adults, alcohol decreased sleep efficiency and rapid eye movement sleep, and increased wake time and next-day sleepiness (Rohsenow 2010). Perhaps the most common scenario for many socially active swimmers is the effect of alcohol the following morning at practice, or at worst, showing up to practice with a hangover. Not surprisingly, neurological qualities are impaired in a hangover: Cognitive functions, such as visual, memory, and intellectual process functions, were decreased during the hangover state (Kim 2003). This may impair motor learning and long-term biomechanical gains.

    Finally, also consider the potential effects of alcohol on recovery, or consuming alcohol after practice or a meet. Prentice (2013) studied 26 rugby players and divided them into a binge drinking group and a moderate drinking group. Authors tracked subjects in the hours and days after the game and found no changes in “[c]ounter movement jump, lower-body strength, repeated sprint ability, CK and hydration status” but did note a significant loss of sleep in the binge drinking group, suggesting that the effects may be felt further downstream due to lack of sleep. In a related work, Barnes (2012) tracked White blood cell count, testosterone, cortisol, creatine kinase and counter movement jump in rugby players for post-exercise drinking after a simulated match. The subjects included an alcohol group (1g/kg bodyweight) and a non drinking group. In the 48 hours following the match, the only significant change was a loss of countermovement jump height among the alcohol group.

    Summary of Alcohol and Swimming Performance

    The old adage of moderation appears most applicable in this area, as the effects of alcohol are dose and time dependent. There are many variables to consider, some of which have not been addressed in the literature, unfortunately the absence of swim specific research. Nonetheless, it is clear that to some level (which is likely different for each individual) and with responsible timing, moderate alcohol consumption should not impair performance. Still, more research is needed in this area to draw definite conclusions.

    References on Alcohol and Swimming Performance

    1. Barnes MJ, Mündel T, Stannard SR. A low dose of alcohol does not impact skeletal muscle performance after exercise-induced muscle damage. Eur J Appl Physiol. 2011 Apr;111(4):725-9. doi: 10.1007/s00421-010-1655-8. Epub 2010 Sep 28.
    2. Barnes MJ, Mündel T, Stannard SR. Post-exercise alcohol ingestion exacerbates eccentric-exercise induced losses in performance. Eur J Appl Physiol. 2010 Mar;108(5):1009-14. doi: 10.1007/s00421-009-1311-3. Epub 2009 Dec 11.
    3. Kim DJ, Yoon SJ, Lee HP, Choi BM, Go HJ. The effects of alcohol hangover on cognitive functions in healthy subjects. Int J Neurosci. 2003 Apr;113(4):581-94.
    4. Barnes MJ, Mündel T, Stannard SR. Acute alcohol consumption aggravates the decline in muscle performance following strenuous eccentric exercise. J Sci Med Sport. 2010 Jan;13(1):189-93. doi: 10.1016/j.jsams.2008.12.627. Epub 2009 Feb 20.
    5. Rohsenow DJ, Howland J, Arnedt JT, Almeida AB, Greece J, Minsky S, Kempler CS, Sales S. Intoxication with bourbon versus vodka: effects on hangover, sleep, and next-day neurocognitive performance in young adults. Alcohol Clin Exp Res. 2010 Mar 1;34(3):509-18. doi: 10.1111/j.1530-0277.2009.01116.x. Epub 2009 Dec 17.
    6. Vella LD, Cameron-Smith D. Alcohol, athletic performance and recovery. Nutrients. 2010 Aug;2(8):781-9. doi: 10.3390/nu2080781. Epub 2010 Jul 27.
    7. Prentice C, Stannard SR, Barnes MJ. The effects of binge drinking behaviour on recovery and performance after a rugby match. J Sci Med Sport. 2013 May 16. pii: S1440-2440(13)00098-4. doi: 10.1016/j.jsams.2013.04.011. [Epub ahead of print]
    8. Barnes MJ, Mundel T, Stannard SR. The effects of acute alcohol consumption on recovery from a simulated rugby match. J Sports Sci. 2012;30(3):295-304. doi: 10.1080/02640414.2011.637949. Epub 2011 Dec 15.
    9. Clarkson PM, Reichsman F. The effect of ethanol on exercise-induced muscle damage. J Stud Alcohol. 1990 Jan;51(1):19-23.
    10. Lecoultre V, Schutz Y. Effect of a medium dose of alcohol on the endurance performance of trained cyclists. Alcohol Alcohol. 2009 May-Jun;44(3):278-83. doi: 10.1093/alcalc/agn108. Epub 2009 Jan 9.

    Written by Allan Phillips is a certified strength and conditioning specialist (CSCS) and owner of Pike Athletics. He is also an ASCA Level II coach and USA Triathlon coach. Allan is a co-author of the Troubleshooting System and was selected by Dr. Mullen as an assistant editor of the Swimming Science Research Review. He is currently pursuing a Doctorate in Physical Therapy at US Army-Baylor University.

    Brief Swimming Review Edition 15

    In an attempt to improve swimming transparency, this brief swimming review will be posted on Saturday. If you enjoy this brief swimming review, consider supporting and purchasing the Swimming Science Research Review for complete monthly article review for only $10/month! Click here to purchase past issues and the most recent review discussed mobility.

    Baking Soda Improves Repeated Sprint Performance, not Improved with Beta-Alanine

    Beta-alanine (BA) and sodium bicarbonate (SB) are two regularly used supplements. In swimming, both of these supplements are meant to buffer acidity, extracelluarly and intracelluarly. This study analyzed the effects of supplementation.

    Thirteen competitive male swimmers (~20.5 years, ~54.4 100-yard freestyle) completed four different treatments:
    1. Placebo (PL)
    2. Sodium bicarbonate (SB)
    3. Beta-alanine (BA) + Placebo
    4. BA + SB
    PL and SB were given at 0.3 g/kg body weight and was ingested 60 minutes prior to two maximal 100-m freestyle swims with a 2 min passive recovery between swims. Four weeks of BA supplementation (4.8 g/day) was given for BA.

    The first maximal swims did not demonstrate a significant difference in time. However, the second 100-m was 1.5 s slower in the PL than the SB. The pH was significantly greater in the SB and in the BA + SB compared to the PL and BA + PL.

    No gastrointestinal distress was noted by the swimmers, yet paraesthesia was experienced by all swimmers consuming BA.

    Take Home Points
    1. SB in acute, small doses may help repeated swimming performance. 
    2. Stomach discomfort has been a common limitation in previous studies. 
    3. BA may still be helpful in swimmers, if used for longer and perhaps higher quantities.
    Related Reading
    Wei Chung discusses Beta-Alanine and Supplements for Swimmers
    Supplements for Swimmers

    400-m Swimmers more Reliable than 1,500-m Runners

    Understanding elite pacing profiles is essential for improving racing strategy. This
    study analyzed lap performance in the 400-m freestyle and 1500-m track athletes.

    Data was collected from five Olympic, World and European international competitions between 2005 – 2011. Eleven swimmers and twelve runners with repeat final appearances were analyzed.

    Typical error (TE) and coefficient of variation (CV) increased in swimming, but significantly decreased in running as laps progressed. CV values were greater in running than swimming in laps 1, 2, and 4, but not different in lap 3 or for total time.

    Take Home Point:
    1. Swimmers have less variability between each individual race, compared to 1500-m track athletes. 

      Youth Swimmers Deficient in Fiber, Vitamin A, and Selenium

      Nutrition is believed to be one variable which influences elite performance.
      Unfortunately, many nutritional studies only assess adult swimmers, not adolescents. This study analyzed the dietary intake of adolescent swimmers in the United Kingdom.

      Twenty-five male swimmers (~15.1 years) who trained and competed on behalf of the Regional and National Development Squads based in the UK.

      All participants recorded their 4 day dietary intake and activity habits during a week, which included ~8 hours of in-water and ~1 hour of dry-land training.

      The dietary intake was as followed:
      • Carbohydrates (6.2 g/kg/d)
      • Proteins (1.8 g/kg/d)
      • Fats (1.9 g/kg/d
      Recommended Nutrient Intake values were deficient for fiber, vitamin A, and selenium, while all other micronutrients were suffice.

      Take Home Point:

      1. Youth athletes in the UK [and likely other developed countries] should consume more fiber, vitamin A, and selenium.  


      1. Russell M, Lali R, Cockburn E, Rumbold P. Dietary analysis of regional and national level youth swimmers in the United kingdom. Br J Sports Med. 2013 Nov;47(17):e4. doi: 10.1136/bjsports-2013-093073.50.
      2. Mytton G, Archer D, Thompson K, Gibson AS. Reliability of retrospective performance data in elite 400-m swimming and 1500-m running. Br J Sports Med. 2013 Nov;47(17):e4. doi: 10.1136/bjsports-2013-093073.6.
      3. Mero AA, Hirvonen P, Saarela J, Hulmi JJ, Hoffman JR, Stout JR. Effect of sodium bicarbonate and beta-alanine supplementation on maximal sprint swimming. J Int Soc Sports Nutr. 2013 Nov 11;10(1):52. [Epub ahead of print] 

      G. John Mullen received his Doctorate in Physical at University of Southern California (USC) and is a certified strength and conditioning specialist (CSCS). At USC, he was a clinical research assistant performing research on adolescent diabetes, lung adaptations to swimming, and swimming biomechanics. G. John has been featured in Swimming World Magazine, Swimmer Magazine, and the International Society of Swim Coaches Journal. He is currently the owner of COR, providing Physical Therapy, Personal Training, and Swim Lessons to swimmers and athletes of all skills and ages. He is also the creator of the Swimmer's Shoulder System, Swimming Science, Swimming Science Research Review, and the Swimming Troubleshooting System.