I don't believe that sit-ups or crunches are must-haves in any core routine. In fact, I steer away from them in favor of other functional core exercises that build a strong midsection, and this "core ...
If you’re a little hazy on the difference between sit-ups vs. crunches, you’re not alone. They both strengthen your core, but the details on how they differ and the benefits of each can be confusing. ...