1) So crunches don't work?
Yes, crunches work your abs but they are ton of better exercises to do for your core. People waste time doing a crazy amount of crunches when they should be doing more effective moves. For example, a study conducted by Peter Francis, Ph.D., and Jennifer Davis, M.A., at the San Diego State University Biomechanics Lab showed that the vertical chair knee raise stimulates up to 210% more abdominal activity than a regular crunch! What’s more, compared to crunches, deadlifts and squats are much more effective for your core and they burn way more calories giving you more bang for each rep you perform.
2) How should I train for maximum fat loss?
Go hard and go heavy. High intensity exercise training has been shown to stimulate lipolytic hormones, including growth hormone and epinephrine, which promote greater post-exercise energy expenditure and fat burning.1 This after-burn effect following intense exercise bouts is associated with a boost in metabolism and is referred to as EPOC or excess post-exercise oxygen consumption. Studies show that high-volume, whole-body resistance training significantly elevates resting energy expenditure up to 72 hours post exercise in both trained and untrained subjects.2,3 As shown by Bo-Han Wu and Jung-Charng Lin in a study conducted at the National Taiwan Normal University, EPOC after training with heavier weights (75% of 1RM) is higher than after training with lighter weights (50% of 1RM). The study also demonstrated that the increased energy expenditure after heavier strength training is mainly derived from fat burning.
3) Why is belly fat so hard to lose?
Everyone is different, but in general your stomach is one of the top areas your body loves to store fat. Unfortunately, it’s also one of the last areas to go when you’re eating right and exercising hard. When I was competing in bodybuilding, my abdominals (lower abs to be specific) were the last body part to get etched out before a show. Changes in hormonal levels due to aging, stress and lack of proper sleep add more unwanted belly fat to your physique. There is no such thing as spot reduction and fat loss (in the abdominals and any other region) is a factor of nutrition, exercise and overall caloric expenditure.