Add Yahoo as a preferred source to see more of our stories on Google. While classic core exercises like sit-ups and crunches are certainly an effective way to train your abs, they are not the only way ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images If you ...

While classic core exercises like sit-ups and crunches are certainly an effective way to train your abs, they are not the only way. If you prefer to stay standing for your workouts, then this ...