When you’re starting to feel really good about your workout routine — like your endurance has increased, and every muscle in your body is getting stronger — that’s exactly the time to push yourself out of your comfort zone. That’s why Charlee Atkins, CSCS, founder of Le Sweat, developed this total-body strength circuit for the second half of POPSUGAR’s 4-Week Workout Challenge. It’s designed to push you to your limits, so you can continue to make progress on your goals.