---
title: "Custom intervals are overrated. 120 % wins."
date: 2025-06-28
categories: ["Training","Durability"]
url: https://www.semiprocycling.com/digest/custom-intervals-are-overrated-120-wins
author: Damian Ruse (SEMIPRO Cycling)
---
# Custom intervals are overrated. 120 % wins.

![](https://www.semiprocycling.com/digest/images/990181d7bd092b2924c6f5c4.webp)

A brand‑new study tested three ways to set the power for one‑minute VO₂ intervals. The old “120 % of maximal aerobic power” came out on top for reliability. Fancy formulas that add sprint data only increased random fatigue.

## What the researchers did

Twelve well‑trained male cyclists rode three separate sessions, each time repeating 60 s hard / 60 s easy until they cracked.

1. Classic 120 % MAP.
2. MAP plus ten per cent of anaerobic power reserve.
3. MAP plus twenty per cent of glycolytic power reserve.

The classic prescription gave the tightest spread in time to exhaustion (about twenty one per cent). The two “personalised” options were far less consistent, hitting thirty five and forty five per cent. Heart rate, oxygen use, and lactate were identical. The only difference was how unpredictable the hard bouts felt.

## Why it matters to your riders

Predictability is gold. A session that delivers the same load every time streamlines recovery planning, lets you stack blocks, and strengthens durability without surprise setbacks. Extra complexity adds noise, not signal.

## How to use it next week

- Take the best three‑minute power from recent data (or do a fresh three‑minute all‑out test). That is a solid field estimate of MAP.
- Multiply by 1.20. That is your target wattage for each one‑minute work bout.
- Pair each hard minute with one minute of very easy spinning below half of MAP.
- Stop a set when you miss the target by ten per cent. Two quality sets are plenty.
- Add one repeat per set each week until you reach ten total hard minutes. Then change stimulus.

## Stick with the simple 120 % rule for bread‑and‑butter VO₂ work. Save lab‑heavy formulas for research projects or special cases. Your riders will adapt faster and recover on schedule.

## Read the abstract (PMID 40525689)

[https://pubmed.ncbi.nlm.nih.go...](https://pubmed.ncbi.nlm.nih.gov/40525689/)

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## On my mind: Getting in shape is rented, not owned

Last month I tried to “bank” fitness. Big Sunday ride, felt invincible, so I skipped two easy spins, grabbed take‑away twice and stayed up late. By Friday my legs were bricks, heart rate was up, and every pedal stroke cost double. Miss a few payments and the landlord always notices.

Fitness has a daily rent. Drop one payment and the others tighten. Skip two and performance slides. Skip three and you start over with interest.

Treat these dues like brushing your teeth. Non‑negotiable, automatic, barely noticed until they lapse. Block them into your diary, back them with alarms, and check them off each Sunday. Momentum builds quietly, then suddenly.

Pay today’s rent. Tomorrow’s ride will feel lighter, and next month’s goal will thank you for it.