Just three minutes a week of exercise can make you fit. That’s 180 seconds out of 604,800. This involves just three minutes of High Intensity Training (HIT) a week for four weeks and the results can be seen in dramatic improvement in insulin sensitivity (on the order of 24%), and aerobic fitness. Aerobic fitness has consistently been shown to be a very powerful predictor of future health. There are various forms of HIT, depending on the intensity and duration of the effortful bursts, and your fitness goals. High Intensity Training usually includes a number of shorts bursts of intense and effortful exercise with short recovery breaks in between. The 3 minutes of High Intensity Training can be broken up for further ease and convenience. Just do one minute every couple of days or so. And go ahead and break up that minute into three 20 second sessions.
When you do HIT, you’re using not just your leg muscles, but also your upper body including arms and shoulders, so that 80% of your body’s muscle cells are activated, compared to 20-40% for walking or moderate intensity jogging or cycling. Active exercise also seems to be needed to break down the body’s stores of glucose, deposited in your muscles as a substance called glycogen. Smash up these glycogen stores and you create room for more glucose to be sucked out of the blood and stored.
After you eat, your digestion starts putting glucose into your bloodstream. This causes the pancreas to release insulin. If your insulin sensitivity reduces, the pancreas has to release more and more insulin to keep blood glucose levels stable. Abnormally low insulin sensitivity is known as insulin resistance and it is a main risk factor for metabolic syndrome, which increases the risk for coronary artery disease, stroke, and type 2 diabetes. Hence aerobic fitness is of utmost important. Remember, in HIT, ‘intense’ means ‘intense’. In fact it means that, if the three minutes are to be effective, they must hurt. It’s all-out effort, taking you well out of your comfort zone. That level of discomfort makes some activities better-suited to intense training than others. Cycling and swimming seem to work well, but running could be less effective. The pounding involved in repeated sprinting could lead to injuries, depending on a runner’s experience and stride mechanics. However, it’s suggested that if you have any medical conditions, please talk to your doctor about it first.