I have written about high-intensity short-interval training several times, because more and more research is teaching us how to maximize our exercise benefits. Research has proven that it’s a very effective way of exercising. So how can you use this principle when exercising to get the best results?
The secret is revealed in the reviewed research.(Cochran AJ,et al. 2014). These researchers compared:
High-intensity short interval training performed on a stationary bike, done either for 30 seconds with 4 minutes of rest in between intervals repeated 4 times.
One set of continuous exercises that were matched for total energy output and required 4 minutes to complete as fast as possible.
Strangely enough, even though energy output was the same, the results were not!
After the first exercise session both protocols produced similar increases in markers of AMPK, p38 MAPK and PGC-1alpha mRNA expression. These are proteins related to mitochondrial energy production in muscles. These proteins were also measured after six weeks of exercising three times per week. Here are the surprising results:
The continuous exercise protocol did not produce the same increase in these markers after six weeks as the short interval protocol with rest in between sets did. It turns out that intermittent stimulus is important for maximizing muscle adaptation.
If you want maximum results from exercise it needs to be short, very intensive intervals. You need rest in between the intervals to recover.
When you exercise this way your actual exercise time will be very short, only two minutes per session.
Walking has been promoted as an easy way to lose weight and stay in shape, but is it really effective? That is exactly what the reviewed researched investigated.
The participants a total of 4511 adults aged 18-64 years were included in the study(Fan JX, et al. 2013). The body mass index (BMI) were measured and accelerometers were used to evaluate minutes per day of high intensity bouts of walking of either 10 minutes or more, or less than 10 minutes. This was compared with lower intensity walking of 10 minutes or more per day and lower intensity walking of less than 10 minutes per day.
It was found that both higher intensity short-duration or walking long-duration were related to reduced BMI or risk of overweight/obesity. Neither the short walks or the long walks of lower intensity were found to have a positive effect on BMI or risk of overweight/obesity.
The message is that even less than 10 minutes of walking per day can help you prevent weight gain if it is high intensity walking. This is another example showing that it is the intensity of the exercise you do that is important, not the time you spend doing it. The more intense you exercise, the less time you need to spend doing it.
We all know that physical activity provides numerous health benefits. A recent study which included 32,269 women examined the relationship between both vigorous and non-vigorous physical activity and its effects on postmenopausal breast cancer risk (Leitzmann MF, et al, 2008).
It was interesting that it was only vigorous activity in lean women that was found to be associated with reduced risk for postmenopausal breast cancer. The same relationship was not found for women with a body mass index of greater than or equal to 25.
Vigorous activity can be a variety of things. Some of the things that researchers mentioned were running, biking uphill and competitive tennis, but there are of course other things you can do as well. You want to keep in mind when you exercise to do it hard enough so that you get your heart rate elevated and you start to breathe heavier.
If you exercise harder, you also need to spend less time exercising to get in shape. That is why top athletes usually incorporate interval training in their routine which means short bursts of high intensity exercise alternating with low intensity or rest.
Leitzmann MF, et al. Prospective study of physical activity and risk of postmenopausal breast cancer. Breast Cancer Res. 2008 Oct 31;10(5):R92.