Squat (lunge): Add a dumbbell and try not to let your knees exceed your toes. So the suggestion here is to consult the coach to standardize the movements and let him design a set of movements. If you are a private teacher, I suggest you finish ten years of classes and get familiar with the movements. It's enough to find a feeling, and you don't need long-term employment. Take my own club as an example. A coach's personal monthly fee is 3000 yuan, and the head coach is 5000 yuan. This price is too expensive to be worth it. Basically, the process of going to the gym is 5 minutes warm-up+anaerobic training (40 minutes -60 minutes)+20 minutes aerobic training+final stretching! ! ! Usually it is to adjust the diet structure (don't say it, otherwise it will be a lot)+sleep. Therefore, the fitness industry is really uncomfortable, and the level of coaches is uneven: either bodybuilders know the profession, do not know the business, and do not understand the needs of users; Either a small white face-the total muscle mass is not much, there are lines, and it needs maintenance (personally tried).