Each group should be exhausted during training, starting from the first time! Because the novice's physical fitness is limited, you can't just warm up two groups and add up the weight bit by bit like a professional athlete. Ordinary people in groups 3-4 are already very tired. So be exhausted from the start!
Suppose you practice 10 times in each group. The first 8 times are as standard as possible, and the last 2 times can be borrowed. In a word, we must do our best. The first eight are bedding, which makes the muscles congested and swollen, and the last two are stimulating the muscles at the peak. Experienced bodybuilders greet others to protect their last two extreme thrills!
After a full rest, the next group can do 10 times. Don't use the professional athlete's 1 minute rest method, or you won't have the strength to lift this number in the next group. It is suggested that the interval is about 2 minutes, and then gradually compress the interval of J.
I hope it helps you.