Have you ever wondered what the least amount of exercise you could do while still obtaining some sort of health benefit from it?
We live busier lives than ever and for some, the idea of exercising 30 minutes to an hour isn't realistic nor enjoyable. For most of us, we love our workout and look forward to it but that isn't the case for everyone. There are a lot of people who dread exercise or lack the time to exercise. It could be their job, family life or just a lack of priorities. I still believe that exercise should be one of your main priorities because it enhances every aspect of your life, but that isn't the point of the this discussion. The point of this post is to answer the question above:
What is the least amount of exercise you could do while still obtaining some sort of health benefit from it?
Luckily, we live in the age of the internet and I don't have to search through 100s of books to find the answer, instead, I can head to pubmed.com to search over 1000s of studies. And yes, you can definitely become Alice in Wonderland and fall down a rabbit hole, which tends to happen from time to time, but I digress.
While searching pubmed I came across a two day study from the Journal of Metabolism Clinical and Experimental. The study’s goal was to figure out whether or not a single maximal sprint bout could yield the same benefits as four maximal sprint bouts. They did this by having each participant (overweight male) in the study take part in three different 2-day trials. On the first day, they either took part in no exercise, four 30 second maximal sprints (SIT), or a two minute maximal extended sprint (ES). On day two of the trial, the participants had their fasting blood sample taken and had an oral glucose tolerance test to determine insulin sensitivity. Based off the results, the scientists concluded that a single sprint bout can increase fat oxidation in overweight/obese sedentary men versus the non exercise group (1).
However, the single sprint bout was not nearly as effective as the four maximal sprint bouts (SIT) when it was compared for fat oxidation (68% increase for SIT versus 38% for ES) (1). But, the extended sprint (ES) did improve insulin sensitivity versus the non exercise group which is needed for a nation suffering from Type II Diabetes (i.e insulin resistance. Furthermore, both workouts had positive impacts on fat loss compared to the non exercise group. Thus, the study shows us that even one sprint bout has benefits for fat loss versus not exercising.
So how could just one, two minute sprint increase fat loss and improve insulin sensitivity ?
Most likely it was due to the fight or flight response that the sprint imposed on the body. When your body enters this stress induced environment it secretes a bolus of hormones to help you produce the energy needed to sustain your energy output. One of these hormones is called noradrenaline (norepinephrine). When noradrenaline is secreted it activates hormone sensitive lipase which breaks down triglycerides (fat cells) into fatty acids and turns off the production of insulin so that your body can use it for energy. This reduction in insulin leads to improved insulin sensitivity which increases feelings of fullness from food. So next time you are short on time or willpower, hop on the nearest bike and push as hard as you can for 2 minutes and call it a day. It might not be the most effective workout routine, but as the study shows, it is still improving fat oxidation and insulin sensitivity, two things that are essential to living a long, healthy life.