insulin

We know that exercise is a critical part of a good cardio workout, but how much do we need? 45 minutes at least 3 times per week is the dogma we all follow.

You have to love our viewpoint here in the United States.  We don’t want to spend money on research to determine how much exercise is too much.  Nope.  We want to know just how little we have to do and still get a benefit.

Now, I’m not saying we shouldn’t be efficient with how we spend our time exercising, but this article begins to push the limits of efficiency.

For those who are patients of the clinic, read this blog regularly or have heard me speak at an event know I am a very big fan of short burst interval training.  For most, this means 30 seconds of high intensity exercise on something like a stationary bike or treadmill.  Perform 4, 6 or even 10 of these sessions with rest times in between and you have likely just met the demands for what you need to keep your heart healthy.

Most often, when I present this information to patients and groups I am speaking to, they are very happy to hear that hopping on the treadmill for 45 to 60 minutes and running through an entire album on your Walkman may be way overkill.  (Ok..so maybe it’s NOT your Walkman, but you can tell how long it’s been since I’ve been on a treadmill….).

This approach has been holding its own in the medical literature for the past few years (you can read up on the latest research in a previous article that can be read by clicking here) and I feel confident sharing this concept with others.  So, in summary, YES–5 minutes worth of actual exercise may be enough.

Keep in mind that this is NOT jogging for 30 seconds and taking a break.  This is a darn near all out burst for 30 seconds.  The rest time between sets is basically however long it takes your heart rate to return back to normal.  Overall, it’s pretty simple and could reasonably be completed in 20 minutes (shorter if your rest time improves).

But, as I mentioned in the beginning of this article, what if we could shorten this time even further?

I’m not ready to promote this as a standard approach to exercise for all of my patients, but this particular study certainly makes one ponder.  In this small study, researchers took 10 overweight or obese men and had them perform 3 2-day trials.  Here were the 3 types of exercise:

1. None.  Full blown couch potato.
2. 4 all out 30 second sprints, followed by 4 1/2 minute breaks.
3. 1 single intense exercise burst, matched in the amount of calories burned in group #2 (average 198 seconds).

Sounds pretty simple as far as designs go.  So what did they find?

• Insulin sensitivity was improved by 44.6%  in the single burst exercise compared to the couch potato.
• There was not much of a difference in insulin sensitivity between the short burst and couch potato.
• In the day following the interval training, fat oxidation was improved by 38%.
• Most striking, the day following exercise fat oxidation increased by 63% in the single burst (Tweet this).

Wow.

A mere 3 1/2 minutes of straight high intensity exercise led to a huge increase in fat burning the next day.  That’s under 4 minutes and slightly more than 3 minutes.

Granted, this study was done on a group of men who were arguably out of shape to begin with, but this is likely the population that needs the most help anyway.  So I don’t know if I’m ready to cut patients down to 3.5 minutes of exercise a day, but I will definitely keep my radar up on this one.

How much do YOU exercise per day?