Guess you're a novice? Beginners must be gradual, with less weight and fewer times. Before exercise, they should warm up 15 minutes. Specifically, they should jog before starting to exercise, so that their bodies can gradually adapt to high-intensity training, so as not to be easily injured. When you exercise, you may feel a little heavy back pain, so you can't get quick success and instant benefit in fitness. Another point is that you can't exercise the same muscle group every day, that is, you can't practice biceps today and change to another muscle group tomorrow. Muscles can only be increased in the process of destruction and repair, and you should also give muscles a time to recover. It seems meaningless to practice biceps butt pain, because you are not practicing in one position at all. There is only one possibility. Your training is too heavy and involves thigh muscles. I wish you an early success!