A strong back and abs go great together like summer and barbecues. And you’re going to want both. Especially when you’re on vacation and hitting up all those barbecues, pool parties and other shirt-optional events.

Shaping up the large muscle groups at the center of your body isn’t just a vain, aesthetic thing: Both are key for warding off injuries and preventing aches and pains that come from working out other muscles and everyday living.

However, you may feel like vacation is a time to take a break. Its easy to create excuses not to workout – especially when you’re faced with a gym-less hotel. But with the following exercise you have zero excuses not to work on these important muscle groups. A week’s worth of binge-eating at barbecues can do some serious damage when it comes to your hard-earned physique.

And to build a strong back and core, you don’t need any equipment – just two small hand towels, a slick surface and your own body weight. The bonus is you’ll come back from vacation stronger and ready to take on a new week at Elite.

Towel Plank Knee Tucks

Benefits: Builds core, cardiovascular and back strength

Sets/Reps: 3×15

  • Press out through heels, sliding legs out into a full plank position.
  • Avoid sagging or lifting hips—body should make a line from heels to head.
  • Brace abs in tighter and slide legs back in to start position (knees still hovering). That’s one rep. 

Want to try more variations? Pair the following exercises together and create a full workout. 

Towel Plank Variations

Side-to-Side Glider Plank

Sets/Reps: 3×15

  • Assume a plank position with your elbows bent 90 degrees and feet shoulder-width apart on hand towels.
  • Move your left foot in an arc away from your body, and then pass it beneath your body, to your right.
  • Do all your reps; then repeat with your right leg.

Mountain Climber

Sets/Reps: 3×15

  • Take the two small towels and fold them into squares and step on them with the balls of your feet.
  • Place your hands on the ground and drive your right leg back.
  • Quickly switch so your right leg is in front and your left leg is back (like you are doing mountain climbers).

Superman Planks

Sets/Reps: 3×15

  • Assume a plank position with your elbows bent 90 degrees and feet shoulder-width apart on hand towels.
  • Drag left knee toward your left elbow.
  • Return to starting plank position and then drag right knee toward right elbow.