21-Day Abs Challenge: Day 21

This expert-backed routine will help you become a stronger, more efficient runner.

Danielle Zickl and Gifs by Julia Hembree Smith |

You did it! You made it through 21 days of lockdown. Now go forth and smash your final workout! Day 21 is here, get moving…

By now you probably know that runners need strong cores to maintain efficient running form and posture. But you might not realise that those muscles around your middle are one of the first parts to fire up when you start running.

“Your core is your power center, the home base of your body,” says Lindsey Clayton, RRCA run coach and instructor at Barry’s Bootcamp in New York City. “Having a strong core stabilises your body as you run, and adds power to your arms and legs to drive your body forward.”

To give you some extra motivation for building your core, we put together this 21-day ab challenge with the goal of boosting your overall strength so you can head into winter training with more speed and efficiency than before.

But before you start, Clayton has some words of advice: You don’t have to power through each move or do them as fast as humanly possible. Instead, take your time and breathe through them, fully inhaling and exhaling through each rep. Performing each move with control will help you reap the most rewards.

functional training abs challenge
Designed by Freepik

How to do this challenge:

Each workout listed below is its own circuit. Do Workout 1 on day one, Workout 2 on day two, Workout 3 on day three, so on and so forth. Once you finish Workout 6 on day six, start back at the beginning. Cycle through Workouts 1 through 6 every day for 21 days straight.

Clayton recommends performing each exercise for 50 seconds with a 10-second rest in between each round. For the first 15 days, aim to complete 2 to 3 rounds, and work up to completing 3 to 4 rounds for the last 15 days. As always, check with your doctor before starting any new exercise program and stop at any point if something feels off.

People photo created by yanalya – www.freepik.com

Workout 21


Lie facedown with your legs extended and your hands placed on the ground next to you on each side of your head. Lift your arms, chest, and legs off the floor, extending your arms out in front of you. Contract your glutes and thighs and relax your shoulders and neck. Lower back down and repeat for a total time of 50 seconds.

Windshield Wiper

Lie faceup on the ground with your arms straight out from your sides so body forms a “T” and your legs straight up toward the ceiling. Keep your abs braced and lower your legs to the right as far as you can without lifting your shoulders off the floor. Swing your legs to the left and lower as far as possible without lifting shoulders. Continue alternating from side to side for a total time of 50 seconds.

Mountain Climber

Start in a high plank position with your arms straight, wrists over shoulders, and body forming a straight line from your head to your ankles. Engage your core and draw your left knee as far as you can toward your right elbow. Bring your left foot back to starting position. Then draw your right knee as far as you can toward your left elbow. Continue alternating between legs as fast as possible for a total time of 50 seconds.

Russian Twist

Sit on the floor with your knees bent and your feet off the floor. Lean back so that your torso and upper body are at a 45-degree angle. With your elbows bent and your hands together, rotate your torso from one side to the other for a total time of 50 seconds.

Jackknife With Stability Ball

Start in a high plank position with your shoulders over your wrists, but instead of placing your feet on the floor, rest your shins on a stability ball. Engage core to pull the stability ball toward your chest and lift your hips up as you roll the ball forward to your feet. Return to starting position and repeat for a total time of 50 seconds.

READ MORE ON: 21-day challenge abs abs challenge abs workout coronavirus covid-19 indoor training indoor workout

Copyright © 2024 Hearst