Get your upperbody and core chiseled with this 15-day pull-up bar challenge. It is beginner-friendly so, as long as you access to a pull-up bar, you can take it up! The rules are simple: hit the given amount of reps by splitting the total into as many sets and taking as much rest as you need. Make it challenging - do as fewer sets as you possibly can. 2 Minutes rest between sets is the recommended rest time.

On core days while doing knee-ins with twists make sure you tighten up your abs and bring your knees up as high as you can to get the most out of the exercise. Can't do twists just yet? Start by bringing your knees up without a twist first until you feel confident you can add the twisting motion.