3 Things You Didn’t Know About Ultra-Endurance Swimming

Many associate ultra-endurance swimming with pain and fatigue. However, we know little on the subject, despite it’s growing popularity. Now, many swimmers have performed ultra-endurance swimming during practice through the forms of tests sets (Timed 30 minute swim or timed 3,000) and Allan Philips has discussed some of the risks/benefits of this training previously. Most swimmers would likely agree these sets are arduous times. For one, there is no break. Another difficulty is the pure mental strength required for the task. These are two reasons some coaches (for one Bob Bowman) enjoy these sets. Unfortunately, these are anecdotal reasons for this form of training. Scientifically, little is known on ultra-endurance swimming. Here are three misconceptions on ultra-endurance swimming.

1. You Don’t Reach Maximal Fatigue: Fatigue is multifactorial, associated with a decrease in muscle performance. Swimming fatigue is most noted with an increase in energy cost and a change in biomechanical stroke parameters. Despite the frequent discussion of physiological factors influencing fatigue, psychological factors are also thought to impair swimming. For example, when swimming for an extended period of time rating of perceived exertion (RPE) increases. Conscious information is the memory of the RPE of a familiar task. When an athlete is performing a novel exercise or distance, a conservative pacing approach is performed. This is why many can raise their effort level at the end of a task. The decision to cease the task would be mainly due to two psychological factors: the potential motivation and the perceived exertion. A recent study analyzed the effects of a 25-km time trial on national and international swimmers (not ultra-endurance swimmers) and found a significantly higher RPE, but not a maximal RPE during the swim. The reason for not reaching maximal RPE may be due to the novelty of the race for these swimmers (mostly sprinters) or the positive experience of finishing the task. Now, the results may be different with highly trained ultra-endurance swimmers, but for most swimmers, you aren’t even reaching maximal effort during ultra-endurance swimming! 
2. You Don’t Get Hungry! Hunger, like fatigue, is a complicated subject. One would expect a swimmer to become hungry during an ultra-endurance race due to the number of calories burned. This high caloric expenditure creates a negative energy balance, yet during a 25-km swim, swimmers don’t report hunger! The authors concluded “the reduction in leptin compensated for a negative energy balance due to the prolonged effort through an increase in appetite”. Despite the lack of hunger, consuming some calories is paramount for ultra-endurance training. For example, if an ultra-endurance swimmer is not consuming calories they may lack in energy for maximal performance. The swimmers may also risk hyponatremia, low blood salt. Hyponatremia is a deadly condition, which kills a couple of ultra-endurance runners each year. Now, the swimmers don’t need to eat something, but could simply drink a fluid containing calories.  
3. Hand Path Doesn’t Change: Many coaches avoid ultra-endurance sets as they are adopting the principle of specificity. However, this study noted no change in the hand path of the swimmers during an ultra-endurance race. This doesn’t imply they are using “race” specific biomechanics, but that they are locking into a pattern which isn’t changing form. Since the hand path isn’t changing one could argue this form of training isn’t as negative as previously thought.

These three things you didn’t know about ultra-endurance swimming are from one study, of non-ultra-endurance-swimmers. More research on trained ultra-endurance swimmers is warranted, as one would assume they can reach higher levels of fatigue during this racing.

If you are prescribing ultra-endurance training sets, keep this notion in mind, as safety and maximal performance are two main goals!

Reference

1. Invernizzi PL, Limonta E, Bosio A, Scurati R, Veicsteinas A, Esposito F. Effects of a 25-km trial on psychological, physiological and stroke characteristics of short- and mid-distance swimmers. J Sports Med Phys Fitness. 2014 Feb;54(1):53-62.

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.