It is almost ubiquitous now that exercise is good for you. Whether it is low intensity, high intensity, resistance or otherwise, each and all exercise has its benefits. But is there an upper limit?

Many people will have heard of over-training. And if it is prolonged it can be a significant detriment to performance, but what causes the drop in performance and is it bad for your overall health and function?

A recent publication from Swedish researchers looked to understand what happens at a cellular and metabolic level when we increase exercise to excessive levels. Over a 4 week period they gradually increased their exercise volumes and intensities to determine whether High intensity inveral training sessions would continue to have beneficial effects on mitochondrial function (the energy centre of cells) and our ability to regulate glucose (the energy source). What they found was fascinating.

As exercise loads increased our ability to use and regulate glucose and produce energy through mitochondria is enhanced until exercise loads reach a tipping point of being excessive. In this study they tried to push the envelope, asking the participants to perform all out efforts repeatedly day after day. What they found was that once you reached this point your mitochondrial function reduced significantly and disturbed your glucose and insulin regulation. So not only did performance go down, but your general metabolic health was being adversely affected. So much so that the glucose and insulin regulation of the these participants started to look similar to that of type 2 diabetes patients. And although these subjects were not elite athletes, they researchers were also able to demonstrate in elite populations that there is a disruption in their glucose regulation and insulin secretion. 

So does hard training hard a bad idea for your health?

In short no. Training hard will provide for significant benefits to your health and physical function. What is not great for your health is training that is ever increasing and constantly intense. The body requires opportunities to recover and days in which the physical activity that you undertake is less than maximal. 

In short to maximise the physical and health benefits you get from your training be sure to have harder and easier days in your program and look to explore measuring your general health with a medical professional when you notice that your training may be dropping off in performance  despite being maintained at a high intensity and especially if it has been increasing in volume over time. 

To read the article head to: https://www.cell.com/cell-metabolism/fulltext/S1550-4131(21)00102-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1550413121001029%3Fshowall%3Dtrue