---
title: "When Does Strength Training Become Endurance Training?"
date: 2025-06-07
categories: ["Strength"]
url: https://www.semiprocycling.com/digest/when-does-strength-training-become-endurance-training
author: Damian Ruse (SEMIPRO Cycling)
---
# When Does Strength Training Become Endurance Training?

![](https://www.semiprocycling.com/digest/images/79a5dc1814249d6fbc369348.webp)

Have you ever wondered at what point your strength workouts turn into endurance sessions? The answer lies in a concept called Critical Occluding Tension (COT).

A recent study from Fliss et al. (2025) revealed that muscle blood flow—and consequently oxygen delivery—is significantly limited at exercise loads between 30% and 40% of your one-repetition maximum (1RM). Below this threshold, your muscles enjoy ample blood flow, allowing endurance adaptations such as improved oxygen utilization and increased capillary networks to dominate. Above this threshold, muscular strength becomes crucial, as blood flow is naturally restricted by higher muscular tension.

Endurance-trained athletes excelled at performing more work at lower loads (below 30% 1RM), thanks to greater capillarisation and mitochondrial content, enabling efficient oxygen delivery and use. Resistance-trained athletes, however, dominated at higher loads due to superior peak strength.

For cyclists, understanding your personal COT can guide targeted training:

Below COT (~30% 1RM): Emphasise aerobic and endurance-focused strength work to enhance muscular oxygen use and fatigue resistance.

Above COT (>40% 1RM): Prioritise higher-load strength training to boost maximal strength and performance under occluded conditions, such as steep climbs or sprints.

In short, knowing your COT helps you tailor your training to optimise performance exactly where you need it most—whether grinding up a mountain or sustaining power over a long ride.

Reference: Fliss et al., Scandinavian Journal of Medicine & Science in Sports, 2025.

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## On my mind: Make Now Matter

Today could be the tipping point you’ve been waiting for.

Right now, your potential is as accessible as it ever will be. Every moment holds energy—grab it, harness it, turn it into momentum.

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Step in today—make now matter.  
  
Damian