Weight training
As with many kinds of exercise, weight training people should drink enough water. Some say a weight training person should drink about 200ml of water every 15 minutes. Drinking a "sports drink" similar to Gatorade does not help more than water for water needs but may help with some kinds of salts that you may need after exercise. If a very large amount of water is used it is possible to drink too much water, so the use of care is important.