8-9 o'clock should be the digestion process after meals. Proper exercise can help digestion and avoid fat accumulation.
Don't limit your exercise to a time period. Everyone who engages in sports knows that you can train most of the time every day (except when you eat, sleep and rest, of course! And the most effective degree of exercise is moderate and deep fatigue, and the effect is the most obvious! Especially effective for the increase of muscle mass!