One intense minute: what interval training can and cannot do

The study by Jenna Gillen and Martin Gibala with three 20-second sprints (2016), meta-analyses in heart patients, safety and a simple programme for beginners

2 min read

Translated from the Albanian original by the editors. Shqip

Download PDF Share
Illustration: waves of breath, a symbol of short, intense efforts
Original illustration by the lexoshpejt editors. Not a historical photograph or object.
Settings

Line spacing

Typeface

Appearance

High-intensity interval training, known as HIIT, alternates short periods of hard effort with periods of rest or light movement. For example: 30 seconds of cycling as fast as possible, then two minutes at an easy pace, and so on several times.

The one-minute study

In 2016 the Canadian researchers Jenna Gillen, Martin Gibala and colleagues compared two ways of training in 27 young men who were mostly sedentary. For 12 weeks, three times a week:

  • One group did 10 minutes on an exercise bike, with only three all-out 20-second sprints, so one minute of hard effort in total.
  • The other group did 45 minutes of moderate continuous cycling, plus warm-up and cool-down.

At the end, both groups had similar improvements in cardiorespiratory fitness, about 19 per cent, and in insulin sensitivity. The interval group spent five times less time.

In patients

A 2014 meta-analysis by Kassia Weston and colleagues, in patients with heart disease, high blood pressure, overweight and metabolic problems, found that supervised interval training improved cardiorespiratory fitness almost twice as much as moderate continuous training.

Lack of time is no excuse for not moving. But high intensity is no excuse for skipping caution.

The limits

  • Many studies are small and short, often with young people.
  • All-out sprints are unpleasant. Many people do not keep them up outside studies.
  • Intervals do not fully replace the benefits of daily movement and strength exercises.

Safety

People with heart disease, uncontrolled high blood pressure, or who have not been active for a long time should talk to their doctor before starting intense training. In patients, HIIT has been tested mainly under supervision.

A simple start

  1. Warm up for 3–5 minutes with walking or easy cycling.
  2. 30 seconds fast, hard enough that talking is difficult, but not to exhaustion.
  3. 90 seconds slow.
  4. Repeat 4–6 times, then cool down for 3–5 minutes.
  5. Twice a week is enough to start, along with daily walking.

Sources and further reading

  1. Gillen, J. B., Martin, B. J., MacInnis, M. J., Skelly, L. E., Tarnopolsky, M. A. & Gibala, M. J. (2016). Twelve weeks of sprint interval training improves indices of cardiometabolic health similar to traditional endurance training despite a five-fold lower exercise volume and time commitment. PLoS ONE, 11(4), e0154075. PubMed
  2. Weston, K. S., Wisløff, U. & Coombes, J. S. (2014). High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: A systematic review and meta-analysis. British Journal of Sports Medicine, 48(16), 1227–1234. PubMed

Read on