By far, SIT-UPs.
Best for reducing belly fat?
- Eat small meals 5 times per day.
- Drink a 1/2 – 1 gallon of pure water per day (not including coffee, tea, soft drinks, etc.)
- Work out 3Xs per week
- Do body-weight exercises e.g., jumping jacks, push-ups, mountain climbers, squats….. And don’t tell me you are too old. MODIFY them so you can do them with no injury. It’s very easy.