Now they just use suppliments or foods for the same effect,many players now,what are we gonna do pinch their as on the way to the court with a Pova Preseason Index (PPD) and say maybe we have to test you now.Did someone say vasodialotor.
So for athletes It appears the drug has two main effects.
One of them changes mitochondrial function allowing more fat (long chain fatty acids) to be burned without overloading the system.
Physiologically fats are very efficient at storing energy because they don't soak up water. However as anyone who's turned 40 and suddently has a few extra kilograms around the belly can tell you. The body prefers to burn anything else before going into Beta-oxidation and using that stored fat.
If you are trying to lose fat weight the trainers will tell you to calculate your target heart rate and try to sustain that for 30 minutes. This is a proxy for a physiological condition where your body is using energy at a rate where burning fat is prefered. If you work harder than this, your body will not burn fat because the B-oxidation step is a bottleneck that prevents enough energy to meet demand from releasing. Therefore the body will go into anaerobic mode and burn glycogen without sending it through the electro transport chain and form lactic acid instead. Conversely if you work less hard than this the body, will not bother burning the fat because it doesn't need that much energy and can get by with burning free glucose/glycogen completely. So the tdrug expands the energy consumption range where burning fat is prefered physiologically
The other effect is that it's a vasodilator. So it increases blood flow letting muscles work harder without lactic acid build up.
Both these effects are useful in a match but they are equally important in training. You can build your muscles and work harder for longer.