Just about any type of exercise will help to fight fatigue, but how long you do it, the quality of movement and the frequency will also play a relevant part in its efficacy.
We all know the last thing tired people want to do is work out. If you are attempting to get more exercise to gain more energy, it is important to schedule the time to do so, as remaining sedentary will also make you remain tired. The best thing to do is to get up and partake of some sort