90 Seconds A Day of HIIT Might Be All You Need

man and woman passing an exercise ball while doing sit ups at a gym

Evan Stevens

We know that HIIT can be used to improve parameters of health in diseased individuals, but can it work in healthy individuals/a whole population, and if so, how might it work?

The first talk of the session examined just that by having individuals perform single leg cycling tests; one leg would perform short, higher intensity intervals (4 x 5 minutes at 65% of max wattage) and the other leg would perform longer, continuous exercises ( 30 minutes at 50% max wattage).

Biopsies from each leg were taken and analyzed, as well, whole body measures were taken during each exercise protocol to see how the body changed when stressed differently.

Related Article: A Fun Alternative: Trampoline Workouts

90 Seconds A Day Study

Legs that underwent HIIT showed increases in mitochondrial protein markers greater than moderate intensity continuous training (MICT) in the whole muscle but did not lead to changes in muscle fibre type (type I being slow and type II being fast twitch).

On a whole body level HIIT led to an increased heart rate and increased amount of lactate production (a by-product of working harder).

The researchers wanted to push the workload even shorter and see if the effects of HIIT were still beneficial. They had participants conduct a specific workout:

Two minute warm up + 30 second  work + two minute rest + 30 second work + two minute rest + 30 second work + three minute cool down, three times a week.

Work was done at 86% of the participants’ max heart rate.

So can less than 15 minutes of exercise (90 seconds of total hard work) three times a week translate to better health outcomes even when compared to continuous?

The results seem to indicate so; as little at 90 seconds of hard work resulted in a 19% increase in VO2 Max (in regular, non-elite individuals) over the MICT comparison group, there was an increase in insulin sensitivity that was on par with the MICT group as well as matched increases in stroke volume and cardiac output.

The only area where MICT was better than this HIIT protocol was in body composition where small but significant changes to muscle mass and body fat percentages were noted in the MICT group that were not seen in the HIIT group.


So, form a pure metabolic health standpoint it would seem that HIIT is a viable alternative to improving population health, which goes in the face of most public health models of exercise that calls for moderate continuous exercise. Less work can be used to get the same health outcomes which is great news for people who don’t have the time for or are easily discouraged by longer bouts of exercise.

Take Away:

As little as 90 seconds of really hard work, three times a week can be just as beneficial for metabolic health as longer continuous exercise.

Start tracking your fitness activity and heart rate:

Fitbit Surge Heart Rate Tracker

Related Article: How HIIT Changes Our Body

You Might Like:

Woman performing HIIT outside

Can HIIT Improve Mental Health?

High intensity interval training (or HIIT for short) has fast become one of the most common forms of exercise on the planet. Used by athletes and regular gym goers alike, it has been applauded for...
Someone jump roping

How to Incorporate HIIT in Every Workout

Over the last few years, high-intensity exercise modalities have become super popular. Think about the rise of CrossFit or even the creation of Orange Theory. Both of these workouts are incredibly popular, and both incredibly...
woman walking

The Effects of Sleep Quality and HIIT

Moji Kaviani Quality of sleep appears to be positively associated with both physical and psychological health (Halson, 2016; Lastella et al., 2012). Therefore, numerous studies examined the relationship between physical activity and sleep suggesting that...
woman running stairs

5 Ways HIIT Improves Fitness in Women

Alyssa Bialowas Research poll after research poll, male and female adults express that one of the biggest barriers they face to frequent exercise is lack of time. One common assumption is that exercise and physical...
The Predictors of Longevity You Need to Care About

The Predictors of Longevity You Need to Care About

Yoga warrior pose

12 days of Fitness: 12 Holiday workouts to crush this Christmas

Exercise partners congratulating each other during workout

Exercise After Menopause: What You Need To Know

Family outdoors

Stop Taking Loans on Your Health


New Research on How to Prevent Alzheimer’s Now


Habit Stacking: How to Build Exercise Habits


Best Time to Work Out Based on Sleep Animal


How to Workout to Promote Longevity


Home Based Exercise Goals – Improve Your Fitness and Mental Fortitude

Reset your health

Now Is the Time to Reset Your Health

Leave a Reply