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 [1], 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.

This workout is also based in functional training. "The point of total-body strength training is to target muscle groups we use every day," Atkins explained. In other words, when you work your arms, legs, and core, you'll not only gain muscle tone and definition, but you'll also notice that everyday tasks (like moving from sitting to standing) feel easier. How's that for a payoff?

20-Minute, No-Equipment Total-Body Strength Workout

Directions: Complete each exercise for 40 seconds, followed by a 10-second recovery. You'll do two rounds total of each set with a one-minute rest in between rounds. Complete both rounds of the bodyweight set before moving on to the core finisher. Here's a seven-minute dynamic warm up to do before you begin. Cool down after your last set with these foam-rolling exercises [2] that will help restore your muscles.

Exercises:
Bodyweight Strength Set

• Split squat
• Plank row
• Dead bug and hollow hold
• Seal jacks

Core Set

• Plank reach
• Side plank

Split Squat

• Stand with both feet together. Take a step forward with your right foot like you're going into a lunge, allowing your left heel to come off the ground. Place your hands on your hips for stability.
• Slowly bend your knees until your right thigh is parallel to the floor and your left knee nearly touches the ground. (At the bottom of the move, both knees should be bent at about 90 degrees.) Keep your torso straight and core pulled in toward your spine.
• Drive through your feet to push back up to standing.
• Immediately go back into a split squat, and repeat for the full 40 seconds.
• Once the 40 seconds is up, rest and complete the move with your left leg forward.

Plank Row

• Start in a high plank position with your feet wider than your hips for added stability.
• With your core tight and your glutes engaged, exhale, stabilizing your torso as you lift your right elbow to row; feel your right shoulder blade sliding toward your spine as you bend your elbow up toward the ceiling.
• Keeping your neck long and energized, return your hand to the ground and repeat the movement on your left side.
• Continue alternating arms for 40 seconds.

Dead Bug and Hollow Hold

• Lie on your back with a neutral spine and your hips and knees at right angles. Press your left elbow into your left knee and, with your elbow straight, rest your right arm against the right knee.
• Press your lower back into the floor and draw your belly button into your spine. Lift your shoulders off the ground, while continuing to squeeze your abs and glutes.
• Keep your torso and spine stable as you lengthen your right arm and leg out until they are almost parallel to the floor.
• Pause briefly before bringing your arm and leg back to the starting position.
• Continue this movement for the full 40 seconds.
• Once the 40 seconds is up, rest and complete the move on the left side.

Seal Jacks

• Start with your feet together, and extend your arms straight out in front of your chest, palms facing in.
• Open your arms out to the sides as you jump your legs wide.
• Land on the balls of your feet, then quickly bring your legs and arms back to standing.
• Continue jumping out and in as quickly as possible for 40 seconds.

Plank Reach

• Begin in an elbow plank with your feet slightly wider than your hips for added stability.
• Reach your left arm straight out, tapping your fingers to the floor in front of you. Bring your arm back to the mat, then reach forward with your right arm.
• Continue alternating arms for 40 seconds.

Side Plank

• Begin by lying on your side. Bring your right elbow directly under your right shoulder. Engage your core, press your right elbow into the floor, and rise into a side elbow plank.
• Stack your heels or modify by staggering your feet so your left foot is just in front of your right.
• Reach your left arm up toward the ceiling, which will help you lift your waist.
• Hold for 40 seconds, and repeat the plank on the opposite side.