5 reasons you swim slower as you age (and it isn't a decrease in strength)

5 Reasons you Swim Slower as you Age (and it isn’t a decrease in strength)

admin Biomechanics, Blog, Dr. John Mullen, Latest&Greatest 5 Comments

Take Home Points:

  1. Older swimmers are competing Internationally in sprint events.
  2. Power declines with aging are not the sole reason for decreased speed.
  3. Older distance swimmers are likely to rise in the future. If they can stay healthy and avoid burnout.

Everyone has heard that power and strength declines as we age. Now, this statement is difficult to refute as many aging adults have experienced decreases in power during their activities of daily living. However, as the age of elite swimmers continues to rise (especially in the sprint events), one has to question the relevance of a decrease in land-power vs. swimming power. 

At a recent World Championships, I was surprised to see four of the finalist 30+ years old, as shorter races require more power than endurance races.
Now, this brief example is observational and I'm sure an outlier. However, this trend appears steady as the age of the U.S. Men's World Championship roster was also much older than previous years. If power declines were problematic in swimming performance, one would expect Masters swimmers would decline more in the 50 and 100 events, compared to the distance events, as well as breaststroke since it requires a greater output (Morouço 2011). Yet, this isn't the case as swimming declines are non-significant between events (Hartley 1986). Moreover, swimming decline is well maintained compared to long jumping and cycling (Baker 2010). Also, aerobic performance appears not to significantly decrease, while anaerobic performance does decrease with age (Gent 2013). So, what make swimming different?

2 Reasons Why Power Isn't As Important in Swimming

  1. Power Production Doesn't Correlate with Greater Velocity: Let me explain, sure if you have a swimmer increase their force production while maintaining the same drag, then velocity will increase, but when comparing elite swimmers, those with the greatest force production aren't always the fastest. In fact, when comparing in and out of water strength and swimming speed, it has been suggested more elite swimmers have less correlation (r=0.25) between land based power and swimming speed (Costill 1983).  Now, moderate correlation was demonstrated in bench press and leg press and 25-yard swimming performance in teenagers (Carl 2010). However, force production via tethered swimming was only moderately correlated with bench press (Carl 2010). Power may help predict sprint performance (25-yard), but this research disputes the current trend in older sprinters (Sharp 1982). 
  2. Biomechanics Are the Greatest Influence of Swimming Velocity: Technique is king, so it doesn't matter if you can't create as much power, if you can direct it in the correct path or simply plow through the water! In ~13.4 year-old swimmers, mean power of the arms was related to 50-m times, mean power of the arms for the combined group related to 50-m speed (r = .63). When 50-m times were predicted, arms alone provided as good a prediction (about 40% accuracy) as when leg power was also added. This indicates that arm power is important for sprinting but is not the only factor. Peak-sustained workload predicted 400-m speed (r = .70), still only a moderately related variable. The best predictor in this study for male sprint swimming was the stroke index, an indicator of technique (Hawley 1992). 

5 Reasons Masters Swimmers are Slower (And it isn't a Reduction in Power)

  1. Decreased Training Volume/Intensity: Shorter practices. More family/life obligations. Simply put, many Masters swimmers do not have the time to swim 20 hours a week. This reduction in overall time and volume with swimming reduces the amount of practice and ability to ingrain motor patterns the maintain swimming speed as you age. 
  2. Decreased Coaching on Biomechanics: Many older swimmers train Masters or train by themselves. This form of training lacks biomechanical training, as many Masters coaches do not make biomechanical corrections and individual corrections are highly difficult. Also, if you swim on your own, you are not getting any feedback on technique, the most important aspect for improving swimming performance. 
  3. Decreased Training Intensity: Even though reduced swimming volume reduces swimming speed as you age, the bigger issue is the reduction in swimming velocity. Now, USRPT has provided some high intensity revival to Masters swimmers, it certainly isn't the norm. Most Masters swimmers hop in, do a few thousand yards/meters warm-up, then put on paddles and do an aerobic set. They get their heart rate up and are happy as a clam. Unfortunately, you need to train fast, to swim (stay) fast. 
  4. Altered Body (aka poor range of motion for performing biomechanics): Aging commonly results in increased fat mass and long sitting times. Increased fat mass can alter body position in the water and add more drag. Now, having some fat may benefit flotation (like most elite distance swimmers exhibit), but they still are about 10% body fat, unlike most Masters swimmers at 15-20% (or much higher). As you age, your gravity takes a toll on your posture. A more kyphotic spine, rounded shoulders and stiffer ankles are a few of the impairments negatively influences swimming with aging. 
  5. Increased Stress, Decreased Sleep: Work, family, or whatever, there is often more stress and less sleep. Having increased stress increases injury risk, anxiety, and recovery. A reduction in sleep also increases your injury risk, impairs recovery, and motor learning. 
Now, one can not ignore the influence of power in swimming, but realize this is not the only [or main reason] reason why many slow down with aging. In a sport where out of water power is not as influential on success as other sports, it seems plausible swimming provides an avenue for an extended career in many events. Combine this with improving swimming technology (suits, blocks, etc.) and evolving swimming rules (a dolphin kick on the pullout, crossover IM turns).
One must wonder why International-level endurance swimmers are not as old as sprinters. Perhaps injury and burnout are two reasons for this discrepancy, nonetheless  it is likely older distance swimmers will appear sooner than later. 
What do you think? Why are there not older distance swimmers when there are so many older distance runners?


  1. Morouço P, Keskinen KL, Vilas-Boas JP, Fernandes RJ. Relationship between tethered forces and the four swimming techniques performance. J Appl Biomech. 2011 May;27(2):161-9.
  2. Hartley AA, Hartley JT. Age differences and changes in sprint swimming performances of masters athletes.Exp Aging Res. 1986 Summer;12(2):65-70.
  3. Baker AB, Tang YQ.Aging performance for masters records in athletics, swimming, rowing, cycling, triathlon, and weightlifting. Exp Aging Res. 2010 Oct;36(4):453-77. doi: 10.1080/0361073X.2010.507433.
  4. Hawley JA, Williams MM, Vickovic MM, Handcock PJ. Muscle power predicts freestyle swimming performance. Br J Sports Med. 1992 Sep;26(3):151-5.
  5. Sharp RL, Troup JP, Costill DL. Relationship between power and sprint freestyle swimming.Med Sci Sports Exerc. 1982;14(1):53-6.
  6. Costill, D. L., King, D. S., Holdren, A., Hargreaves, M. . Sprint speed vs. swimming power. Swimming Technique. 1992; May-July, 20-22.
  7. Carl, D. L., Leslie, N., Dickerson, T., Griffin, B., & Marksteiner, A. (2010). Correlation between dry-land strength measurements and in water force generation. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16-19, 2010.
  8. Gent DN, Norton K. Aging has greater impact on anaerobic versus aerobic power in trained masters athletes.J Sports Sci. 2013;31(1):97-103. doi: 10.1080/02640414.2012.721561. Epub 2012 Sep 13.

Dr. John Mullen


Dr. John Mullen, DPT, CSCS is a World renowned expert and speaker in sports training and rehabilitation. He received his Doctorate in Physical Therapy at USC, as well as the Josette Antonelli Division Service Scholarship, Order of the Golden Cane, and the Order of Areté. At USC, he also performed research on strength training and rehabilitation. Dr. John has worked with multiple professional and Olympic athletes, helping them earn Olympic medals.

His dedication to research and individualization spurred him to open COR in 2011. Since 2011, Dr. John has been featured in Gizmodo, Motherboard, Stack Magazine, and much more.

He has worked with the numerous colleges and teams regarding rehab and performance. Before his Doctoral program, Dr. John swam on an athletic scholarship at Purdue University.

At Purdue, Dr. John was an Academic Honorable Mention All-American and was awarded the Red Mackey Award and R. O. Papenguh Award. He also won the Purdue Undergraduate business plan and elevator pitch competition, as well as 1st prize with the Indiana Soy Bean Alliance.

Dr. John was born in Centerville, Ohio and was a 24-time high school All-American Swimmer. Dr. John is still a swimmer and holds a Masters Swimming World and Pacific Swimming Record.

Comments 5

  1. I think you are asking about international-level endurance swimmers are not as old as sprinters… And to that, I ask: Have you not considered the multiple channel and ocean swimmers to be international-level? These events (well over 10K) may not be in the Olympics, but the swimmers, most of Masters ages, are definitely completing longer and longer swims. a few names that come to mind: Michelle Macy (Oceans 7) Steven Munatones, Lynn Cox, Ram Barkai, Ned Dennison, Vicky Keith, Grace Van Der Byl… and a few who have passed: George Young, Henry Sullivan, Matthew Webb, Gertrude Ederle.

    1. Post

      Great comments! The tough things about those races is the exact opposite! We have data on older individuals, but not younger, so it would be interesting to compare ages in those races. Hopefully in the coming years, thanks for the comment!

  2. Pingback: Swimming Science:5 Reasons You Swim Slower as You Age隨年齡增長越游越慢的5個原因 | My Lazy Cocoon

  3. Nice article. Taking into consideration all these factors, there is one component missing and that is sports psychology, as we age we can relate to greater thought process on the outcome. Joint mobility and flexibility can still be maintained and greater directional strength pathway training applied into the biomechanics, swimming fast as we age is still untapped, the neuromuscular pathway of performance values is the key. Also, constant recruitment of fast twitch muscle fiber plays an important role.

  4. I believe the author forgot to mention as masters swimmers age, their VO2 max will decrease, the heart will also weaken, and the NAD level will drop too. These are also huge factors affecting the timing of masters swimmers.

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