Different bodybuilders spend different amounts of time during their exercises at gym. Some spend an hour, some spend an hour and a half and some even spend 2 hours at gym during the training sessions. Question arises, which training session length is optimum and can bring you best results. Studies have shown that our testosterone level reaches at peak in about 45 minutes and then starts decreasing after an hour. So it means training length of 45 minutes can get us good results. Even if you desire to have more exercise, you can divide your workout lengths into 45 minutes per session for morning and evening.
Another question is that how fast or slow you need to perform your repetitions. Different people have different views about this. Some say that you need to perform your repetitions slowly and some say you need to do them fast. My experience tells that performing repetitions faster can bring you good results provided that you have proper control over your repetitions. When I tried to perform the repetitions slowly, very slowly, i found that I started losing muscles instead of gaining them. But when I tried otherwise, I started to get good results but keep in mind that proper control is important. I performed repetitions faster but I was able to control them properly. Besides controlling, you must also make sure that you keep your angles right. What I mean is that every exercise has certain angles which need to be followed to make sure we do it rightly. So if we can control our angle, we can get the real worth of exercise.
So summing up, you need to keep your training session for 45 minutes in length and also make repetitions faster provided that you control your weights and do exercise at right angles. If we lose angle or deviate significantly, our body starts losing its shape and sometimes even look funny because of improper shape. So follow the instruction of control and keeping correct angles to get best results.