If you don't have access to a gym or any weights, this is the perfect strength-training workout — all you need is a wall. Certified personal trainer Caroline Girvan shared this bodyweight workout to target your butt, legs, abs, and arms that's just two exercises: wall sits and elbow planks. Just because it's simple doesn't mean it's not intense. You'll hold each of those exercises for 60 seconds, and let me just tell you — I tried this workout and my muscles were shaking after the first two minutes. This workout was hard, but awesome! It's OK if you can't hold these moves for the full minute. Girvan said to take breaks when you need and count how many breaks you take, so the next time you do this workout, you can try to improve. Find a wall and let's go!