Because of tradition, abdominal exercises are often executed in long sets of 50, 100, or even 200 repetitions. Friends even turn it into a contest: - "I did 4 sets of 200!" - "Really? I did 6 of 300." Who would get the best results from their abdominal exercises in this scenario? No one. Here's why. Long sets of abdominal exercises are not optimal if you want six pack abs. It's basic physiology: muscles grow better on heavy, medium-repetition (about 8-12) sets. Would you train your chest using 4 sets of 200 repetitions? I thought so. Abdominal muscles are no different, and they need to grow if you want them to show. But let's say you can do 12 crunches. Do you stop there (since sets of 8-12 work best)? Of course not. You need to make the crunches harder by increasing the weight you lift every repetition. But how? By positioning your arms differently. Following are 3 arm positions you can use with all abdominal exercises to make them harder and more effective at building six pack abs. 1. Arms along your sides. Can't get any easier. 2. Arms crossed across your chest. Intermediate difficulty. 3. Hands behind your head. 4. Arms overhead. Can't get any harder without adding external weights. 5. Arms crossed across your chest, with some external resistance (a plate or a heavy book, for example). So, keeping with the crunch example, once you hit 12 repetitions with your arms along your sides, start your next set with your arms crossed across your chest. Again, once you can do 12 repetitions with your arms crossed across your chest, start your next abdominal exercise set with your arms overhead. Once your can do 12 repetitions with your arms overhead, you'll want to use some form of external weight (dumbbell, plate, dictionary, etc.). You can hold it across your chest (some people feel more comfortable that way) or at arm's length, overhead. The same principle also applies to all abdominal exercises: when you hit 12 repetitions, increase the difficulty by changing your arm's position. Next time you're about to start a set of 200 crunches, try crossing your arms across your chest. See how many repetitions you can perform this way, and how the burn in your abdominals feel. Then drop me a line at my website below.