Swimming Energy Calculator

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Swim Energy Usage


RER Value Guide

Slow (0.7)
A1 band - warm-up, recovery, cool-down sets
Moderate (0.85)
A2 band - aerobic capacity sets
Intense (1.00)
A3 band - aerobic power, VO2max sets

Data Source: Zamparo P, Bonifazi M (2013). Bioenergetics of cycling sports activities in water.

Coded for Swimming Science by Cameron Yick

Freestyle data

Total Cost

Quick Food Reference

48g Carbs
25g Carbs
Peanut Butter
16g (2 tablespoons) *

Swimming is a Primitive Reflex!

First, swimming is a primitive reflexes! However, primitive reflexes are mainly absent in children and adults, but the influence of primitive reflexes in swimming is not known. As infants, humans have innate reflexes originating in the central nervous system helping us eat,  remove dangers stimuli, and etc.

As we age, these reflexes dissipate, but it shadows of them potentially remain in our motor cortex. These reflexes are beneficial in childhood, but some alter our swimming biomechanics if they remain in the motor cortex.
Swimming Reflex
First, understanding that swimming is a primitive reflex is key. This reflex is not recommended, as submerged infants commonly swallow water, but if submerged in water, infants paddle and kick up until approximately 6 months. This argues the thought of swimming as an unnatural motion, instead it is likely a skill evolutionarily removed from years of terrestrial life. This advocates swimming as it is a primitive reflex, suggesting all should learn this task.  

Even though swimming is a reflexive movement, other primitive reflexes counteract the ideal biomechanics for optimal horizontal velocity.

Asymmetrical Tonic Neck Reflex
This reflex disappears approximately after the fourth month of life. This reflex consists of a baby turning their head to the side (for example the right) and their ipsilateral arm (right) extends, while the contralateral arm (left) flexes. As one breathes during freestyle, their arm on the non-breathing side typically extends and their breathing side is typically bent (although, not always in straight-arm catch freestyle). This opposition of primitive reflexes likely contributes to difficulty of freestyle patterning as a youth. It also questions the innate use of a bent arm catch. However, the bent arm catch does require less shoulder stress, making it the most commonly taught style in children, but the universal use of teaching the bent arm catch potentially hinders use of the primitive reflexes for learning swimming.

Palmar Grasp Reflex
Another reflex disappearing at six months of age occurs as any pressure is placed in an infants palm, as they grasp the object. This seems uninvolved in swimming, but it occurs at turns, specifically altering proper touch turns on flat walls. Imagine hitting a flat wall turn at Nationals, one must block the palmar grasp reflex, as grasping the wall is instinctive. This can also occur during swimming as water is a denser medium than air, potentially forcing reflex inhibition during every stroke. However, this depends on your view on the catch in freestyle and if swimmers actually grab the water, thus a case is likely for each belief.


Adjusting swimming biomechanics for primitive reflexes is purely theoretical, but performing a preprogrammed motion instead of opposing the motion is potentially beneficial. Therefore, consider feeding these reflexes instead of inhibiting their function on your pool decks as swimming is a primitive reflex in humans!

By G. John Mullen 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.