Some people who want to lose some weight decide for the 5:2 diet. But should one exercise on their two “starvation” days?
So far, the small number of studies that have examined at the 5:2 diet have only used obese, sedentary populations. However, the evidence is much scarcer for active people. The results are more likely to be less obvious as training itself improves markers such as insulin sensitivity.
If you train on fasting days you are likely to considerably deplete your glycogen stores. In consequence, you wouldn’t be able to exercise at the same intensity as you would be on a non-fasting day, which means you’re likely to burn fewer calories and you wouldn’t get the improvements you want to achieve. This may also compromise your immune function. In all probability, you’re better off just training more smartly and eating well.