Kind of gets your attention, doesn’t it?
A recent documentary from the BBC’s Horizon Team, (the same guys who gave us the fascinating doco on Fasting), looked at two main areas of exercise and their health benefits.
Firstly, using presenter Michael Mosley as the guinea pig, the team looked at the type and quantity of exercise required to reduce the risk of heart disease and diabetes.
There are two significant markers of health relating to the development of these two diseases, blood glucose levels and Maximum Volume of Oxygen Uptake.
Blood Glucose When we take food it, it starts to be broken down in the mouth (both mechanically by chewing, and chemically with saliva), and then continues to be broken down in the gut. The nutrients leave the gut and enter the blood stream. The blood then transports the nutrients from the broken down food to areas of the body where they are needed. The speed with which the body can deal with an intake of sugar/carbohydrate by transporting it from the blood into the cells is important for maintaining blood glucose levels. The body’s ability to maintain a healthy blood glucose level is a significant health marker.
When our body loses its ability to transport sugar from our blood into our cells, a chronic high blood glucose level develops, which becomes toxic, destroying cells in particular parts of the body. You would have heard of this condition, it’s called DIABETES.
Maximum Volume of Oxygen Uptake (Max VO2)
This is the maximum amount of oxygen we can uptake and use during aerobic activity (the type of activity that gets you huffing and puffing). A higher figure means our cardiovascular system is strong and helps reduce the risk of heart disease.
High-Intensity Interval Training (HIIT)-Just Three Minutes Per Week
Researchers have found that performing very high intensity exercise for very short periods of time improves the body’s ability to move glucose out of the bloodstream — where it can become toxic and lead to the build-up of dangerous visceral fat (fat surrounding organs) — and into muscle tissue, where it is of benefit.
They have found that just three twenty second intervals of this high intensity exercise, three times per week WILL HAVE SIGNIFICANT EFFECTS on both glucose levels and Max VO2.
The exercise is best performed on a stationary bike for ease of monitoring time and controlling the resistance, and to improve consistency of training.
Warmup Even though the “selling” point of the workout is 3 mins of exercise per week, you do actually need to do a bit more than that. You need to warm up first so that your body can reach close to maximal effort.
The Session Pedal hard, hard as you can, go like the clappers, for 20 seconds. Then take a breather. Then do it again, and again. Total is 1 minute of high intensity exercise.
Cool Down I’d advise at least a couple of minutes (though 5 mins would be better) of slow cycling to cool down to help pump your blood out of the working muscles more quickly.
Perform 3 times per week for 12 weeks and according to the latest research, you body’s ability to handle blood glucose will significantly improve.
The other area of exercise which the documentary looked at was incidental exercise, This exercise is part of everyday living: going to the coffee machine, the photocopier, taking the stairs instead of a lift, walking to the shops, washing your own car, household chores, and playing with the kids.
It’s quite easy to accumulate a net 500 calorie deficit a day by increasing your incidental exercise. Walk a little further and a little faster. This 500 calorie energy expenditure is not only important in burning excess body fat, but helps in ‘oiling the wheels’ of our body. Pumping the heart that little bit more, moving blood and oxygen around, contracting muscles are all essential in reducing the risk of heart disease and cancer, two of the big premature killers today.
The Bottom Line
The notion that three minutes a week of HIIT can replace all other exercise and cater for every aspect of fitness is not one that sits well with me. It is sufficient for some aspects of fitness, but the documentary tends to over simplify and gives a misleading message. HIIT would seem to be useful in modifying blood sugar levels, but other studies also show that just getting up and walking around every twenty minutes or so will do the same.
So, if what you want to get from exercise is a reduction in your risk of heart disease and diabetes, knock yourself out doing HIIT three times per week. I’d caution against this if you don’t’ have a good level of fitness already, and my advice would be to build up slowly to this very high level of intensity over a number of months. Like anything new, build up to new levels of intensity or volume slowly.
But if you exercise because you enjoy it, or it makes you feel good, or you like being strong, or you like the social interaction, or you like the clarity of thought you gain from running on your own and getting away form it all, you like your muscles, you like strong tendons, you like your joints to work well, you like the endorphins, you like sweating, you like training for an event and feeling a sense of achievement when you complete it, you don’t like the quick fix attitude of our society, don’t give up on the more traditional exercise routines just yet.
Do include more incidental exercise in your day, and by all means, include HIIT as part of your overall exercise plan, as long as you work up to it gradually. After all, it is only three minutes per week.