We’ve been saying for a minute (pun intended!) that short, high intensity exercise is more effective than long, low intensity exercise. There are countless studies showing this but last week a 12-week study (1) from the esteemed McMaster University in Hamilton, Ontario, Canada made big, big waves. Esquire, GQ, and big shots like the New York Times took notice of this--and you should too!
In this study, a total of 60 seconds (three sets at 20 seconds each) of super strenuous work on an exercise bike proved to be as effective as forty-five minutes (yes forty-five!) at a moderate intensity effort. Cardiorespiratory fitness, insulin sensitivity, and muscular cellular energy all improved the same amount for each protocol.
To examine cardiorespiratory fitness (the interplay between your heart and lungs), VO2max (max amount of oxygen inhaled) was used. Both groups improved their max oxygen uptake by 19%. High cardiorespiratory fitness is important because a lack of it has been shown to be a very strong factor for not only cardiovascular disease but also all-cause mortality (2).
Insulin sensitivity (your body’s ability to regulate blood sugar) was measured with blood sugar tolerance tests 72 hours before and after each exercise session. Both the high intensity exercise and low intensity exercise protocols improved insulin sensitivity dramatically. High insulin sensitivity is vital for health to have a healthy metabolism and prevent the development of type 2 diabetes.
To test the body’s ability to output more energy, citrate synthase (an enzyme that is a catalyst for aerobic metabolism, meaning metabolism that requires oxygen) was looked at. In both exercise routines, citrate synthase showed a marked increase. This is important because the more citrate synthase you have, the better your mitochondria (cellular energy powerhouses) can function and the more of them there can be. A reduced amount of mitochondria has been associated with subnormal fat metabolism and subnormal insulin sensitivity (3).
If you want to improve your body and not spend a ton of time doing it, do some high intensity exercise. You can get all the benefits of extra workout time in under an hour a week with our program, The Full Body Lift Off. We know you want to improve your health and we walk you through how to do it with easy to follow guidelines and direct coaching. Give a high intensity workout a shot and hit us up in the comments to let us know how it goes!