Understanding Energy Systems for Swimming

Understanding Energy Systems for Swimming

A swimmer’s success directly correlates to his / her power, speed and endurance.  To achieve these, training both in-water and dryland should target the most relevant type or a combination of the three basic types of energy systems that power the athletes: the anaerobic a-lactic system, the anaerobic lactic system, and the aerobic system. Depending on the athletes training goal (long distance vs sprints) one system may need more buildup than the others. Thus having an understanding of the energy systems that power different types of swimmers will help athletes select the right set of exercises to best complement and complete their training regimen.

  1. Anaerobic A-Lactic Energy

Bursts of power and speed that require high amounts of short duration acceleration use the anaerobic a-lactic system.  Swimmers rely on this energy system from the instant they explode off the starting blocks through the first few strokes after break out. The anaerobic a-lactic system creates energy that is sufficient to last around 10 seconds.  

  1. Anaerobic Lactic Energy

The anaerobic lactic system provides energy for medium to high intensity bursts of activity that lasts from ten seconds to two minutes. Sprint distance swimmers and mid-distance swimmers rely on this system. The anaerobic lactic system, as well as the anaerobic a-lactic energy system explained previously, are capable of high intensity levels, and do not rely on oxygen for fuel.  

The primary difference between the anaerobic lactic and a-lactic systems is in the amount of time the system can support your race at peak efficiency before dropping off.  We have all seen races (or been the one) where a swimmer who initially looks full of energy and speed suddenly slows down, when his anaerobic lactic energy ran out.

The anaerobic lactic energy system can work at capacity for as long as two minutes. However, the bad news is lactic acid also accumulates in the blood and in muscle cells in the process as waste product from energy usage. The burning sensation in the muscle, shortness of breath and fatigue are all symptoms of lactic acid build up.  Thus it is critically important for swimmers to warm down immediately after their races, especially after sprints.

Strength is important for sprint and mid-distance swimmers whose races depend on the anaerobic a-lactic system and the anaerobic lactic system as their main sources of energy.  Strength can be improved through progressive resistance training. Because the body adapts and becomes resistant to the same training load over time, in order to improve strength and make progress, one needs to constantly change the resistance level, reps, sets and rest period to be effective.  It does not mean the higher the resistance level, the bigger the increase in strength one will get. The biggest benefit for a swimmer comes when the body learns to effectively manage changes in resistance as in swimming races. A word of caution on using weights as part of strength training: muscle cell size increase could affect the body balance of a swimmer, which could in turn affect a swimmer’s stroke positively or negatively.

  1. Aerobic Energy

The aerobic system provides energy for comparatively less intense movements that last anywhere from two minutes to a few hours. Unlike the two anaerobic systems, the aerobic system requires oxygen but takes much longer to overload. Long distance races that primarily depend on continuous sustained efforts rely on the aerobic system.

Endurance swimmers are required to overcome a relatively lower and more consistent resistance for a prolonged period of time. Effective dry-land workout for aerobic training often involves longer sets of low resistance reps, done with a breathing pattern.  Because the aerobic system is an efficient energy system that relies on oxygen instead of muscle strength, distance swimmers are often coached to breath every stroke.


So to conclude, training should be focused on the most relevant energy system depending on a swimmer’s race/distance focus. While the right set of exercise can build power, speed, and endurance, a sound nutrition foundation is also required to ensure that energy and nutrient needs are met and allow for recovery between practices. Lastly, let’s not forget a swimmer’s psychological focus is as important as physical training.

Leave a Reply

Your email address will not be published. Required fields are marked *