Your A-to-Z Guide to a Flat Belly
Brazilian researchers found that obese women who dieted, exercised, and took a 30-milliliter supplement of coconut oil every day carved more inches from their waistlines than did women who dieted and exercised but took soybean oil. (Just choose the virgin, or unprocessed, form of coconut oil.)
Increasing the speed of your crunches (while still maintaining good form) activates more muscles in your trunk than doing more leisurely reps, according to a study in the Journal of Strength and Conditioning Research.
Next: D-Do faster crunches