Exercise during diet provides multiple benefits: ① preserves and builds muscle mass, ② boosts metabolism long-term, ③ accelerates fat burning, ④ prevents rebound (most important), ⑤ improves mood and energy. Recommended: ① week 1–4: light walking 30 min/day (5x/week), ② week 5–8: add light strength (bodyweight, 2–3x/week), ③ week 9+: increase intensity gradually, ④ avoid: extreme cardio that depletes energy. Even 30 min walking daily significantly improves results vs herbs alone.