Friday Interview: Dr. Ricardo Mora-Rodríguez, Ph.D. Discusses Caffeine and Swimming

1. Please introduce yourself to the readers (how you started in the profession, education, credentials, experience, etc.).
I hold a PhD in exercise physiology by the University of Texas at Austin. I was a swimmer until I was 14 yr old, with a best PR of 1:07 for 100 m backstroke. I teach exercise physiology to PE and physiotherapy undergraduates. I direct the Exercise Physiology Laboratory at Toledo (Spain) were we focus on thermoregulation and ergogenic aids research.

2. You recently published an article on caffeine and acute resistance training power and velocity at different loads. Could you briefly tell us what we know about caffeine as an ergogenic aid in power events?
It is well known that caffeine improves endurance performance, however, its effects on muscle force and power are less well established. Our study addresses what dose of caffeine improves the speed of movement when we load the muscle with increasing resistances.

3. What were the main results of your study?
The main message of the study is that if muscles ought to overcame high resistances, then you need to ingest a high caffeine load (9 mg/kg BW). This could apply in swimming to the jump-start out the blocks and the first strokes in a 25 mts sprint. However, for longer distances where the force applied is not as high doses of 3-6 mg/kg are enough

4. You note some GI and side effects in the heavy caffeine groups. How do you recommend dosing caffeine in first time users?
Sure, first I will try a 3 mg/kg dose and do a follow up on the side effects. You can use the table of our paper.

5. At what age do you feel caffeine is safe to begin use? Why?
Some kids are consuming energy drinks full of caffeine as a recreational drink because of TV publicity. However, I would not recommend its use until late adolescence (15-16 yrs old).

6. Do you think caffeine should be used at practice or simply as a competition aid? For example, will habituation occur with repeated use?
Terry Graham in Canada has some nice studies about habituation and for endurance performance caffeine still works even in habitual users. Again less is known about habituation for force and power performance.

7. Based on your study, do you think caffeine would improve 50-meter swimming performance (~20 - 25 seconds in length)? Middle distance performance (50 - 140 seconds)? Distance (230 seconds and longer)?
Hard to extrapolate our bench press or squat single contractions into a whole body technique like swimming. My best guess is that it may help on short-distances (50 mts; Our paper). However, in 100, 200 and 400 mts it may not help much, and also it elevates lactate in blood (Pruscino CL, IJSNEM, 2008). In 800 and 1500 mts it may help again (McIntosh, CJAP, 1995). Pending to do more controlled studies in larger populations of swimmers.

8. Who is doing the most interesting research on caffeine in the field? What are they doing?
Lawrence Spriet and Terry Graham are the reference group in this area.

9. What makes your research different from others?
It is the first time that the factor dose of caffeine ingested and resistance to overcome are crossed to identify which caffeine dose would be optimal for each sport tasks. Now, the reader should try to identify at what percent of 1 repetition maximal (1 RM) their sport takes place.

10. Which teachers have most influenced your research?
Dr. Edward F. Coyle.

11. What are the most common mistakes you see in those using caffeine?
Caffeine and coffee are not the same. When using it as an ergogenic aid it is better to ingest the product pure.

12. What research or projects are you currently working on or should we look from you in the future?
We just published a paper analyzing the effect of the time of the day (morning vs afternoon) on force and a 25 mts sprint in young swimmers

Thanks Dr. Mora-Rodríguez

Friday Interview: Wei Chung discusses Beta-Alanine and Supplements for Swimmers

1. Please introduce yourself to the readers (how you started in the profession, education, credentials, experience, etc.). 
My name is Weiliang Chung and I’m currently doing my PhD on sports nutrition and exercise performance. This follows my degree in exercise science and a yearlong internship at the Australian Institute of Sport.

2. You recently published an article on beta-alanine (BA) supplementation and swimming performance. First could you explain the theoretical mechanism of action with BA? 

There are a few proposed mechanisms on how beta-alanine supplementation works. Briefly, beta-alanine supplementation results in increased carnosine content in the muscle. Carnosine has been proposed to be a pH buffer, anti-oxidant and can improve muscle contractile function. The main role that many researchers believe that carnosine loading (via beta-alanine supplementation) is the increased ability to buffer the protons produced from prolonged, high intensity exercise.
Some good reviews that I highly recommend for readers to get a better idea of beta-alanine supplementation would be:
  • Harris and Sale (2012) – Beta-alanine supplementation in high intensity exercise
  • Derave et al. (2010) – Muscle carnosine metabolism and beta-alanine supplementation in relation to exercise and training
3. Could you briefly explain your findings?
Our paper is free to download at:

We measured training performance at 0, 4 and 10 weeks (training and supplementation period) and competition performance 2 weeks before and after the training period. There was a slight benefit of beta-alanine for training performance at 4 weeks but no clear effect was found at 10 weeks. No clear benefit of beta-alanine was seen for competition performance.

4. Another study by Painelli (2013) used a shorter supplementation period, but higher dose of BA and found significant results in swimming performance. Do you think your results would differ if you used a similar protocol?

I do not think that the supplementation strategy would matter. Stellingwerff and colleagues (2011) tested two different dosing protocols – High/Low (3.2 g/day for 4 weeks followed by 1.6 g/day for 4 weeks) vs. Low/Low (1.6 g/day for 8 weeks). The resulting increase in muscle carnosine content was similar between the High/Low group at 4 weeks and the Low/Low group at 8 weeks (both groups have supplemented a total of ~90 g of beta-alanine). It is demonstrated here that the increase in muscle carnosine content is dependent on the total amount of beta-alanine consumed rather than the daily dosage.

However, readers have to bear in mind that our study did not standardize training or nutrition, as it is a great challenge to control the practices of coaches and highly trained swimmers (some Olympic level). It is very difficult to detect clear effects in uncontrolled studies, as there are many confounding factors not limited to injury and different training programs. Nonetheless, we attempted to test the efficacy of beta-alanine supplementation in a real-life scenario.

5. Do you recommend BA for elite swimmers? 

My short answer would be yes, based on the laboratory-based research that has been emerging over the years. However, I would recommend that athletes pay primary focus on the basics such as consistent training, nutrition and injury prevention.

6. If a swimmer wants to try BA, what dose and period do you suggest? Also, paraesthesia is a common side effect with BA, what do you think causes this and do you think it is harmful?

It depends on what period of the training calendar the swimmer is in. As previously mentioned, the absolute dosage is the main factor in carnosine loading. Therefore, depending on the type of beta-alanine supplement (pure or sustained-release) are available on your shelves, you could have a slow loading protocol leading into competition or a faster loading protocol prior to a high-intensity training block or competition.

As for side effects, ingesting more than 1.6 g of pure beta-alanine in a single dose has resulted in significant paraesthesia. This uncomfortable “pins and needles” sensation is possibly consequential from sensitization of neuropathic pain specific neurons in the skin. The documented side effects from supplementation usually fade away after a few hours. Therefore, I would recommend ingesting no more than 1.6 g of beta-alanine (preferably sustained-release) per single dose and more than 3 hours in between doses.

7. Gemelli (2013) wrote: "the diminution of antioxidant defenses increases kinases inhibition which decreases pyruvate and creatine content" occurs with BA supplementation. What do you think of their findings and the risks of BA? 

The beta-alanine supplementation protocol that Gemelli and colleagues used here are three doses of 0.3 mg/g, equivalent to 0.3 g/kg body weight in a single day. There is absolutely no reason to implement that dosage in humans as it equates to 21 g per dose, with a total of 63 g of beta-alanine in a single day for a 70 kg individual.

8. Do you recommend any other ergogenic aids to swimmers? 

Other ergogenic aids that have shown ergogenic properties include caffeine, sodium bicarbonate and nitrates. However, always practice the use of ergogenic aids in simulated competition conditions during training so athletes new to dietary supplements know what side effects to expect.

9. Who is doing the most interesting research on supplementation and swimming? What are they doing? 

With regards to beta-alanine supplementation and exercise, some of the names to look out for are Wim Derave, Bruno Gualano, Roger Harris, Craig Sale and Trent Stellingwerff. I also expect more researchers to be included to that list as the athletic population pays more attention to beta-alanine. Louise Burke, John Hawley, Asker Jeukendrup, Andrew Jones, Stu Phillips and Luc Van Loon are names that I would look out for with regards to sports nutrition research.

As for swimming research, it is difficult to pin down names and topics. Those who focus on swimming research are often from the field of biomechanics. I would suggest that Bruce Mason and David Pease from the Australian Institute of Sport are leading the field.

10. What percentage of Olympic-level swimmers do you think use BA?

 It is difficult to estimate what percentage that would be, but I would guess that 75% of top Olympic-level swimmers have experimented with beta-alanine supplementation.

11. What percentage of Olympic-level swimmers do you think use some ergogenic aid? 

There is no doubt that most top Olympic-level swimmers use dietary supplements. These can include vitamins, minerals, protein, ergogenic supplements or even energy gels/drinks.

12. Which teachers have most influenced your research? 

This list would be endless as I am lucky enough to have the chance to work with many world-class applied and academic researchers alike. I have to highlight my internship at the Australian Institute of Sport, which was priceless; they really strike a nice balance between applying cutting edge sport science while maintaining excellent rapport with athletes and coaches. I have a lot of respect for Allan Hahn (former Head of Physiology), Louise Burke (Head of Sports Nutrition), David Pyne (swimming and team sports) and David Martin (cycling).

13. What research or projects are you currently working on or should we look from you in the future? 

I am now collaborating with the Belgian research group of Wim Derave at Ghent University. We are investigating the effect of beta-alanine supplementation on endurance cycling performance so stay tuned.

Blood-flow Reistance (BFR) Training Improves Elite Athletes

A lot of research suggests blood-flow resistance (BFR) training increases strength, hypertrophy, and testosterone. At Swim Sci, we first broke down this phenomenon in 2010 (Blood-Flow Resistance Training)!. Since then, a lot more research has been published, even research on swimmers (see Swimming Science Research Review)! We have also been fortunate to have interviews with experts on the subject (Friday Interview: Dr. Alan Mikesky, and soon Zach Pope). Now, the benefits discussed have mostly been found in elderly or non-athletic populations.

However, a recent study looked at BFR training in elite rugby players and note:
"[g]reater improvements were observed (occlusion training vs control) in bench press (5.4±2.6 vs 3.3±1.4kg), squat (7.8±2.1 vs 4.3±1.4kg), maximum sprint time (-0.03±0.03 vs -0.01±0.02s) and leg power (168±105 vs 68±50W). Greater exercise-induced salivary testosterone (Effect Size: 0.84 to 0.61) and cortisol responses (ES: 0.65 to 0.20) were observed following the occlusion intervention sessions compared to the non-occluded controls; however the acute cortisol increases were attenuated across the training block (Cook 2013)".

This study adds evidence of performing BFR for sports enhancement. Now, the applicability for swimming is uncertain, as these benefits may simply have occurred from an improvement in ground reaction force (GRF). However, the possibilities of BFR are swimming performance, as well as health parameters (potential increased hypertrophy and bone mineral density, both two necessities for the aging swimmer) exist.

Recently, I started a training blog (selfishly to help track my progress and motivate me as I strive for my swimming goals). In a recent post, I describe how I use BFR. This new form of training still has many uncertainties, so please consult a physician before use. Lastly, if you are interested on being on a remote swim team which includes monthly Skype discussions and daily written workouts, contact us for more information!


  1. Cook CJ, Kilduff LP, Beaven CM. Three Weeks of Occlusion Training Can Improve Strength and Power in Trained Athletes. Int J Sports Physiol Perform. 2013 Apr 23. [Epub ahead of print]
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. He is the founder of the Center of Optimal Restoration, head strength coach at Santa Clara Swim Club, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

Beets and nitrates for Sporting Improvement?

I knew he was doping, but beeting too...
As the use of nitrate drinks increases, most notably with beetroot juice, a quick review and recommendation seems imperative. First, it is necessary to state, it seems no negative health benefits result from the consumption of nitrate drinks. However, it seems nitrate drinks only appear beneficial for untrained athletes. First, let us consider the potential benefits of nitrates.

Lactate Reduction

Some hypothesize lactate reduction would occur with nitrate consumption. However, Nezmar (2011) notes no reduction in lactate, but a reduction in [K+] in untrained individuals.

NO Alterations
Now this doesn't mean no alterations, but nitric oxide alterations. Totzeck et al., noted  baseline NO2(-) correlates with lactate threshold and predicts exercise capacity during an incremental cycle test in highly trained athletes, Wiley and his colleagues argue that it is more than likely that the ability to produce more NO quasi 'on demand' is the underlying cause of the performance increases (Dreissigacker. 2010; Totzeck. 2012). However, these baseline levels are higher in trained vs. untrained athletes, suggesting the NO are more likely in untrained populations (Dreissigacker 2010).

VO2 Max

Lansley (2011) provided 0.5 L of 6.2 mmol nitrate two and a half hours prior to maximal cycling output. This study noted no alteration in VO2max in untrained cyclists.

Conversely, another study notes a lower O2 cost at a sub-maximal task. This suggests improved mitochondrial efficiency (Jones 2013). Once again, this was performed in an untrained population.

Lastly, Peacock (2012) noted no alterations in oxygen uptake after consuming a potassium-nitrate drink in elite cross-country skiers. 

Prevents Creatine Phosphate Depletion
In swimming, specifically short course, the creatine phosphate system or alactic system is
commonly used. The physiology of nitrates for preventing creatine phosphate depletion is still being studied, but this hypothesis suggests NO increases skeletal muscle glucose uptake, the correspondingly lower blood glucose levels the researchers observed in the active arm. This indicates  readily available glucose will spare the PCr stores.

Prevent Potassium Leakage
Lactic Acid and Muscular Fatigue by Dr. Ernest Maglischo is a great read about the myths and facts of lactate and fatigue in swimming. One area not discussed by Dr. Maglischo is the possibility of electrical imbalances contributing to fatigue. As postponed fatigue may result  if the the distribution of K and Na ions inside and respectively outside of the muscle cell are maintained.
Maximal Power
Not sure this has the best nitrate ratio...
In this same study, an improvement in maximal power occurred (Lansley 2011). In another study providing 2x250 mL/day of beetroot juice, Kelly (2013) did not note an improvement in maximal power in recreationally trained cyclist.


The same Kelly study notes an improvement in performance (Kelly 2013), unfortunately no alterations in power or watts were noted.


It is clear, more research is needed on elite and trained athletes. Moreover, the reason for potential improvement is still muddy even in un- or moderately trained athletes. Personally, for trained populations, I don't see nitrates or beets providing any ergogenic benefit. However, if you wish to try beetroot juice, simply try consuming beetroot juice 3 hours before a workout/performance, there is no harm in that! 

  1. Nemzer B, Pietrzkowski C, Spórna A, Stalica P, Thresher W, Michałowski T, Wybraniee, S. Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts. Food Chemistry. 2011; 127:42–53.
  2. Wylie LJ, Mohr M, Krustrup P, Jackman SR, Ermιdis G, Kelly J, Black MI, Bailey SJ, Vanhatalo A, Jones AM. Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance. Eur J Appl Physiol. 2013 Feb 1.
  3. Kelly J, Vanhatalo A, Wilkerson DP, Wylie LJ, Jones AM.Effects of Nitrate on the Power-Duration Relationship for Severe-Intensity Exercise.Med Sci Sports Exerc. 2013 Mar 7. [Epub ahead of print]
  4. Jones AM, Bailey SJ, Vanhatalo A. Dietary nitrate and O₂ consumption during exercise. Med Sport Sci. 2012;59:29-35. doi: 10.1159/000342062. Epub 2012 Oct 15.
  5. Peacock O, Tjønna AE, James P, Wisløff U, Welde B, Böhlke N, Smith A, Stokes K, Cook C, Sandbakk O.Dietary nitrate does not enhance running performance in elite cross-country skiers.Med Sci Sports Exerc. 2012 Nov;44(11):2213-9. doi: 10.1249/MSS.0b013e3182640f48.
  6. Dreissigacker U, Wendt M, Wittke T, Tsikas D, Maassen N. Positive correlation between plasma nitrite and performance during high-intensive exercise but not oxidative stress in healthy men. Nitric Oxide; 2010; 23:128–135
  7. Totzeck M, Hendgen-Cotta UB, Rammos C, Frommke LM, Knack-stedt C, Predel HG, Kelm M, Rassaf T. Higher endog-enous nitrite levels are associated with superior exercise capacity in highly trained athletes. Nitric Oxide. 2012; 27:75–81
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. He is the founder of the Center of Optimal Restoration, head strength coach at Santa Clara Swim Club, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

Oral Contraceptive Cycle Phase Does not Affect 200 free

Rechichi C, Dawson B. Oral contraceptive cycle phase does not affect 200-m swim time trial performance. J Strength Cond Res. 2012 Apr;26(4):961-7.

The use of oral contraceptives (OC) is common in female athletics, with swimming not being an exception. However, there is no conclusion on the effects OC have on performance. OC typically work by administering ethinyl estradiol for 21 days (OC consumption phase. During this phase, suppress endogenous estrogen and progesterone production. The 21 day consumption phase is followed by 7 days of placebo. During this level, hormone levels are not suppressed, hence fluctuations in sex hormones depend on the phase of the OC.

Decreasing estrogen and progesterone production is believed to enhance athletic activity by altering substrate metabolism (decreasing lipid oxidation and increasing carbohydrate oxidation) and increasing aldosterone (increasing H+ buffering capacity).

This study examined the effects of the OC cycle on 200-meter swimming performance and associated measures of heart rate, blood lactate, pH, and glucose.

What was done
Six competitive swimmers and water polo players participated in this study. The trials were randomized and each participant performed a 200-meter swim trial during each phase:
  • between days 17 and 21 of the OC consumption phase
  • between days 2 and 3 of the OC withdrawal phase
  • between days 6 and 7 of the OC withdrawal phase
Blood samples were taken before and after each trial.

There was no significant difference in performance, mean stroke rate, peak heart rate, blood glucose, and body composition between the different trials. Mean blood lactate was lower in the trial between 6 and 7 days compared to the consumption phase. There was also a significant difference in blood pH, with the withdrawal phase having a higher blood pH.

There was also no significant difference in progestrone, but difference in estradiol.

There was no difference in performance during the different OC phases. However, the decrease in blood lactate and an increase in pH during the withdrawal phase are suggested to be due to an increase in fluid retention from the decreased progesterone and increased aldosterone during this phase.

Practical Implication
It appears 200-m free performance is not altered by the phase of OC consumption. Therefore, women should not be concerned about the timing of their OC and meets.

The study is interesting in one other regard, as a significant difference in blood lactate was not associated with exercise performance. This suggests lactate is not associated with poorer performance.

Swimming Science Research Review 
This is a piece of the July Swimming Science Research Review. Read Swimming Science Research Review September 2012 for a complete list of the articles reviewed.

Sign-up here
 to receive this month's edition and all future publications for only $10/month. Each edition covers articles ranging from biomechaincs, physiology, rehabilitation, genetic, and much more! These reviews  explain the latest sports science research in straightforward language.
This will help you apply knowledge in the review to the pool deck, separating yourself from your peers!
And don’t worry, there’s no fixed commitment period, so if you don’t want to continue receiving the monthly publication, you can just cancel your payment whenever you want.