But when you feel overworked, overwhelmed and struggling to make sense of the new norm, it is tough to exercise regularly – much less reap the benefits.
According to a study published in Medicine & Science in Sports & Training a 23-minute HIIT session per week can not only increase aerobic capacity, lower blood pressure and lower body fat … but an increase is almost as effective as doing three 23-minute sessions per week.
Researchers created three groups. One did HIIT a workout three times a week, another did a HIIT workout per week, the third did three moderate intensity per week, and the fourth group did nothing. (I have been part of a few research studies and have never been in the "do nothing" group.)
Both HIIT exercise groups lost more body fat than the other two groups, but one time per week. Weekly group lost almost as much ̵
There's still one big caveat: you can't just spin easily on a workout bike. You can't just breeze with the elliptical. You can't just knock out twelve reps with dumbbell bicep curls weighing five pounds while checking your email with your free hand.
Your HIIT training must be a real HIIT training.
HIIT stands for High Intensity Interval Training. The principle is simple. You go almost as hard as you can for a short period of time, and then "rest" for enough time to let yourself recover enough to go hard again.
In running words, it can mean sprinting for 30 seconds, jogging for 30 seconds, sprinting for another 30 seconds, etc. Here are many different HIIT options, some aerobic, others strength focused.
And here's a seemingly simple but annoyingly difficult example:
 Whatever HIIT training you do, remember that you have to go far beyond what feels comfortable. (Which means you should contact your doctor to make sure you are doing it.)
Your lungs need to burn. Your muscles need to burn. If it is not difficult – very difficult – then do not do a HIIT workout.
Roughly, the "on" effort should be 80 to 90 percent of the maximum heart rate, and the recovery period of 65 to 70 percent. (Generally, you can calculate your maximum heart rate by subtracting the age from 220.)
Or if you are doing longer "on" sessions, you can rest completely for shorter periods; it all depends on the training.
What will not vary is that a HIIT workout is not fun.
But again, you end the workouts in a third of the time it takes to grind you through an hour-long spin class.
And science says you will get significant benefits from doing it only once a week.
That gives you more time to be as efficient and effective as possible with everything else on your plate.
Posted on: March 27, 2020
The opinions expressed here by the Inc.com columnists are their own, not those of Inc.com.