Physical and Energy Requirements of Competitive Swimming Events
Authors: David B. Pyne, Rick L. Sharp
DOI / Source: 10.1123/ijsnem.2014-0047
Date: 01 July 2014
Reading level: Intermediate
Why This Matters for Freedivers
Freediving dynamics and finning are “swimming with breath-hold constraints,” so efficiency is everything: wasted effort burns oxygen and accelerates CO₂ build-up. This paper gives a clear, practical framework for how intensity, technique, drag, and energy systems interact—helpful for planning pool/open-water conditioning and for understanding why “better technique” often beats “more effort.”
Synopsis
This paper is a broad, coach-friendly overview of what actually powers swimming performance across different race distances, and why water makes the whole problem harder than running the “same length of time” on land. The authors explain that swimming events range from short, explosive efforts (tens of seconds) to long endurance races (many minutes), so performance draws on a mix of energy systems: the “immediate” phosphate system for starts and sprints, anaerobic glycolysis for sustained high intensity, and aerobic metabolism for longer events and for recovery between hard repeats.
But the main message is that technique and drag often decide how expensive a given speed is. In water, resistance is huge and rises fast as speed increases, so small changes in body position, streamlining, and stroke mechanics can massively change energy cost. The paper highlights that different strokes have different energy demands, and that swimmers’ speed naturally fluctuates within each stroke cycle—those speed ups and slow downs matter because re-accelerating your body repeatedly costs extra energy.
A really useful section discusses “economy” (how much oxygen you need for a given pace) and how strongly it varies between people—even at the same speed. Elite swimmers are often far more economical than recreational swimmers, which means they can swim faster with less metabolic stress. The authors argue that this helps explain why improvements in technique and mechanics can sometimes deliver bigger performance gains than chasing small increases in maximal physiology alone.
The paper also links these ideas to training and nutrition in a practical way: different events require different balances of power and endurance, and nutrition supports the ability to repeat high-intensity work (fuel availability), tolerate metabolic stress (buffering), and recover. It’s not a “diet plan” paper, but it sets up the logic for why swimmers (and other aquatic athletes) eat and supplement the way they do.
For freedivers, it’s a helpful reminder that “fitness” is not just lungs and legs—it’s the cost of movement. If you can reduce drag, smooth out unnecessary speed fluctuations, and keep propulsion efficient, you get the same distance for less oxygen and less CO₂.
Abstract
Aquatic sports place unique physical and metabolic demands on athletes because moving in water creates high resistance and makes propulsion efficiency crucial. This paper outlines the energetic requirements of competitive swimming across sprint to endurance events, explains how drag and technique influence the energy cost of speed, and summarizes how power, anaerobic capacity, aerobic endurance, and swimming economy contribute to performance and training needs.