Join Kelsey Wells' New 4-Week Glute-Boosting Challenge

It's easy to lose workout motivation toward the end of the year. The days become shorter, your to-do list becomes longer (thanks, holidays) and cold weather can make a Netflix binge more appealing than the gym. If you tend to let your fitness routine fizzle out at the end of the year only to do a 180 when January 1 rolls around, you're far from alone.

Inspired by that common lack of motivation, the Sweat app launched three new goal-driven, challenge programs to keep you moving. They're intended to give you something to work toward and provide workouts you'll actually enjoy completing along the way. (Related: The SWEAT App Just Launched 4 New Beginner-Friendly Workout Programs)

In addition to a two-week HIIT Energy Boost Challenge led by Kayla Itsines, and a four-week Boxing Fit Challenge with Monica Jones, Sweat launched a two-week Strong Glutes Challenge with Kelsey Wells. To complete the challenge, you won't have to commit to lengthy workouts or even leave your house provided you have basic equipment at home. The sessions range from 15 to 35 minutes and require dumbbells, a barbell, a resistance band, and/or a bench.

The program is also somewhat customizable, so you can tailor it to how ambitious you're feeling. It's made up of four workouts per week, split into glutes and quads, glutes and hamstrings, glutes and abs, and an (optional) upper body workout. But you also have the option to cherry-pick any of the workouts if you want to try them without following the plan. Everything is targeted to an intermediate fitness level. (Related: This 15-Minute Lower-Body Strength Workout from Kayla Itsines Will Reignite Your Gym Motivation)

The strong emphasis on glute strength in this challenge isn't just about looks. "Through my new Strong Glutes Challenge program, I want to help teach women the fundamentals of building lower body strength," states Wells in a press release. "I chose a glute focus because developing strong and functional glutes has so many incredible benefits — from helping to protect your back and improving your posture, to improving your balance and stability, as well as physical performance." (Related: Kayla Itsines' SWEAT App Just Added Four New HIIT Programs That Have Something for Everyone)

If you're on the fence about whether to go for it, you can get a taste of what to expect. This Shape-exclusive workout inspired by the program is intended to promote balance and stability throughout your body by strengthening your quads and glutes. You'll complete glute activation exercises followed by a triset (a group of three exercises) and burnout (a final move to exhaust your muscles), all within 15 minutes. Best of luck.

15-Minute Express Glutes and Quads Workout

How it works: To warm-up, complete three to five minutes of cardio, such as jogging in place or skipping. When possible, follow up the cardio with dynamic stretches such as leg swings and torso twists. Then, complete the activation exercises three times through, resting for 30 seconds between sets. Complete the triset three times through, resting 30 seconds between sets. Complete one set of the burnout exercise. Finally, cool down with three to five minutes of walking and static stretching.

You'll need: A resistance band and yoga mat.

Resistance Band Donkey Kick

A. Start on all fours on a yoga mat with a resistance band looped around upper thighs. Ensure that knees are below hips, hands are below shoulders, and spine is neutral. Draw shoulder blades down and back.

B. Inhale. Exhale and gently draw ribs to hips to engage core. Keeping knee bent and foot flexed, elevate right leg until thigh is in line with spine.

C. Inhale. Lower right leg to return to start but without allowing knee to rest on the mat.

Complete 15 reps. Switch sides; repeat.

Resistance Band Squat Walk

A. Start standing with feet slightly further than shoulder-width apart, toes pointed slightly outward, with a resistance band looped around legs above knees. Looking straight ahead, bend at hips and knees to squat, ensuring that knees remain in line with toes. Ensure that back remains within a 45- to 90-degree angle to hips.

B. Ensuring that hips remain level, take a step right foot out.

C. Step left foot in toward right foot to return to original squat position.

Switch sides; repeat without standing up out of squat between reps. Continue alternating for 20 total reps, inhaling for one repetition and exhaling for one repetition.

Repeat donkey kicks and squat walks for three sets total, resting for 30 seconds between sets.

Double Pulse Sumo Squat

A. Start standing with feet just wider than shoulder-width apart, toes pointed slightly outward. Draw pubic bone to belly button (engage pelvic floor).

B. Inhale. Looking straight ahead, bend at both hips and knees, ensuring that knees remain in line with toes. Continue bending knees until thighs are parallel with the floor in a full squat. Ensure that torso remains as upright as possible.

C. Push through heels and extend legs slightly. Bend knees to return to a full squat position.

D. Exhale. Push through heels and extend legs to return to the starting position. Glutes, hamstrings, and quadriceps should feel tension throughout the movement.

Continue squatting and pulsing for 40 seconds.

Lateral Lunge

A. Start standing with feet just wider than shoulder-width apart.

B. Inhale. Keeping right foot on the floor, take a big step to the left. As foot lands, bend left knee, ensuring that right leg remains straight.

C. Exhale. Extend left knee and transfer weight onto right foot. Step left foot inwards to return to the starting position.

Switch sides; repeat. Continue alternating for 40 seconds.

Single-Leg Glute Bridge and Knee Hug

A. Begin lying face up on a yoga mat with knees bent. Bring one knee to chest, holding it in place with hands, ensuring that spin is in a neutral position.

B. Inhale. Exhale and using glutes to initiate movement, push heel into the mat to lift hips until only upper back remains of the floor, creating a straight line from shoulder to knee. Core should remain engaged and glutes and hamstrings should feel tension throughout movement.

C. Inhale. Return to starting position.

Repeat for 20 seconds. Switch sides; repeat.

Repeat sumo squats, lunges, and glute bridges for three sets total, resting for 30 seconds between sets.

Resistance Band Squat Pulse

A. Start standing with feet further than hip-width apart, with a resistance band looped around lower thighs, and toes pointed slightly outward.

B. Inhale. Looking straight ahead, bend at both hips and knees, ensuring that knees remain in line with toes. Continue bending knees until thighs are parallel with the floor in a full squat. Ensure that back remains within a 45- to 90-degree angle of hips.

C. Exhale. Push through hells and extend legs slightly.

D. Bend knees again to return to full squat.

Continue to pulse for one minute.