I would also advise you to buy parallel bars for training your back and chest muscles. This shell doesn't take up much space, but it contributes to muscle building and helps to improve posture and strengthen the spine. Also, some kind of leg trainer, cardio trainer to warm-up, for example, a treadmill, exercises on it will perfectly prepare you to work with heavier loads and, as a bonus, calories are burned. I drink some instant coffee before a workout (if you are gaining weight, add grass-fed milk and raw honey) or special coffee-based vitamins. In general, I strongly advise for an additional effect to develop a complex of cardio training (I advise the plank exercise), eat right, turn on vitamins and maintain a sleep schedule.