CHEAT: Do weights before HIIT or cardio

DEETS: There's a good reason to do weights first, cardio second – and not just because exhausting yourself in sprints will undermine your strength.

Weights use creatine phosphate and glucose sequentially for fuel while in high-intensity anaerobic exercise, the body initially uses up all of the glycogen in the skeletal muscle and the liver through the glycolysis pathway.

Once it's worked through this, and its glycogen-derived glucose, it relies on liver breakdown of proteins and lipolysis for energy. Doing aerobic exercise first exhausts creatine and glycogen reserves without burning much fat. The subsequent anaerobic session – weights or other – will then be bereft of reserves of energy needed for glycolysis. According to MedFitness, the best strategy for maximum fat burning is 30 minutes of weights followed by cardio, which will primarily use fatty acids for fuel.