You’re ready to burn fat, gain lean muscle, and feel unstoppable –in as little as 21 days. NO GYM.Natural Program delivers a 21 day workout challenge that includes high intensity cardio workouts to torch calories, compound strength exercises to build metabolism boosting muscle, and core exercises to tighten your mid-section—all in just 20 minutes per day.
No gym required. You don’t even need any equipment. All you need is your body weight, commitment and a little motivation. You’ll be performing high intensity cardio exercises, full body strength movements, and core exercises that target every muscle in your body (legs, glutes, core, back, chest, shoulders, arms) to torch calories and increase EPOC (after burn).
Transform Your Body in 21 Day Workout Challenge
1. Jumping Jacks
Muscles Targeted: Full body, legs (inner/outer thighs), core, shoulders, cardiovascular system
How to do it:
- Stand tall with feet together, arms at your sides, core lightly engaged, chest up.
- Jump your feet out wide (shoulder-width or slightly wider) while raising both arms straight overhead — form an “X” shape with your body.
- Land softly on the balls of your feet — bend knees slightly to absorb impact.
- Jump feet back together while lowering arms to your sides — return to start.
- Repeat continuously — keep rhythm fast but controlled.
- Time/Reps: 30–45 seconds continuous (or 30–50 reps)
Why it works: This classic plyometric exercise instantly spikes your heart rate for rapid calorie burn, sharpens coordination and shoulder mobility, activates the lateral plane of the legs (inner and outer thighs) for toning, and acts as the ideal dynamic warm-up. It primes your entire body—muscles, joints, and nervous system—for the higher-intensity work ahead, making the rest of the circuit more effective and safer.
2. Bodyweight Squats
Muscles Targeted: Quads, glutes, hamstrings, core.
How to do it:
- Stand with feet shoulder-width apart (or slightly wider), toes turned out 10–30°.
- Engage core — chest up, shoulders back, gaze forward.
- Push hips back and bend knees — lower until thighs are parallel to floor (or as low as comfortable).
- Keep knees tracking over toes — no caving inward.
- Drive through heels to stand tall — squeeze glutes hard at the top.
- Sets/Reps: 3 sets of 10–15
Why it works: Known as the king of lower-body exercise, bodyweight squats build serious functional strength, sculpt and round the glutes, tone the thighs (front, back, and sides), boost metabolism through large muscle group recruitment (high calorie burn), improve hip mobility, enhance posture, and create a rock-solid foundation for nearly every other movement in the challenge and in daily life.
3. Plank with Leg Lifts
Muscles Targeted: Full core (transverse abdominis, rectus abdominis, obliques), glutes, hamstrings, shoulders, lower abs
How to do it:
- Get into a strong forearm plank with your elbows under your shoulders and forearms parallel to the floor.
- Brace your core and glutes to keep your hips up and back flat.
- Lift your right leg 6–12 inches off the floor, keeping it straight or slightly bent for comfort.
- Squeeze your right glute hard at the top and hold for one second, keeping your hips level.
- Lower your leg slowly and with control to avoid letting your hips drop.
- Alternate legs continuously or do 30 seconds on one side before switching.
- Sets/Reps: 3 sets of 10–15 per leg
Why it works: This dynamic plank variation deeply engages the deep core stabilizers (transverse abdominis), fires up the glutes and posterior chain (hamstrings and lower back), strengthens the lower abs, improves hip extension strength, and enhances overall stability and posture — all while maintaining a mildly elevated heart rate for extra calorie burn and core endurance.
4. Alternating Jump Lunges
Muscles Targeted: Quads, glutes, hamstrings, core, cardiovascular system
How to do it:
- Start in a lunge position: right leg forward, both knees bent about 90°, with the back knee hovering just above the floor.
- Jump explosively upward, switching legs in the air so that your left leg is now forward and your right leg is now back.
- Land softly in a lunge position, absorbing the impact with your bent knees to protect your joints (front knee over ankle, back knee hovering).
- Continue alternating legs in a fast but controlled rhythm, using power from your legs and glutes rather than momentum.
- Sets/Reps: 3 sets of 30 (15 per leg).
Why it works: Plyometric power accelerates fat burn through explosive movement, deeply tones and shapes the legs and glutes (quads, hamstrings, and gluteus maximus/medias), improves balance, coordination, and unilateral leg strength, and creates significant afterburn (EPOC) for continued calorie expenditure long after the workout ends.
5. Burpees
Muscles Targeted: Full body — legs, glutes, core, chest, shoulders, arms, cardio system.
How to do it:
- From standing, squat down, placing hands flat on the floor in front of you.
- Kick your feet back into a high plank position (body straight, core tight).
- Perform a quick push-up (lower chest to floor and push back up; skip for beginners or do from knees).
- Jump your feet forward toward your hands to return to the squat position.
- Explode upward into a vertical jump and reach arms overhead (clap optional).
- Land softly with bent knees, then immediately repeat the sequence.
- Sets/Reps: 3 sets of 10–15
Why it works: This is the ultimate full-body HIIT move — it torches massive calories, builds total-body strength and muscular endurance, engages every major muscle group, and is one of the most efficient fat-burning exercises available. It delivers high cardiovascular demand and significant afterburn, making it a metabolism booster in any workout.
6. Push-Ups
Muscles Targeted: Chest, triceps, shoulders, core.
How to do it:
- Start in a high plank position with hands slightly wider than shoulder-width apart.
- Your body should be in a straight line from head to heels.
- Lower your chest toward the floor, bending your elbows at a 45-degree angle from your torso.
- Keep your body rigid and lower yourself until your chest is just above the floor.
- Push up powerfully, fully extending your arms without locking your elbows.
- Maintain tension in your chest and triceps.
- Repeat with control—no bouncing or sagging.
- Sets/Reps: 3 sets of 10–15
Why it works: Push-ups build upper-body pushing strength (chest, triceps, shoulders), boost overall metabolism through large muscle recruitment, and engage the core intensely for stability — creating a balanced, toned physique that complements the lower-body and posterior work in the challenge. They also improve functional strength for daily life and enhance posture when done with proper form.
7. Superman
Muscles Targeted: Lower back (erector spinae), glutes, upper back (rhomboids, traps), shoulders (rear delts), core.
How to do it:
- Lie face down with your arms straight and your legs together.
- Your forehead should lightly touch the floor.
- Engage your core and glutes and lift your arms, chest, and legs off the floor simultaneously.
- Aim for a lift of 2–6 inches. A higher lift isn’t necessarily better; focus on control.
- Squeeze your shoulder blades and glutes together hard at the top.
- Hold for one to two seconds while keeping your neck neutral (gaze slightly down or forward).
- Lower yourself slowly, returning to the starting position without fully resting.
- Repeat with smooth, controlled movements—no momentum or jerking.
- Sets/Reps: 3 sets of 10–15, or hold the top position longer for an isometric challenge.
Why it works: Superman is specifically designed to strengthen the entire posterior chain (lower back, glutes, upper back, and core), which is often weak from prolonged sitting or forward-focused training. It improves posture, balances out front-core work (like sit-ups), reduces injury risk (especially lower-back issues), and helps create a strong, defined back and lifted glutes—essential for a symmetrical, athletic physique.
8. Sit-Ups
Muscles Targeted: Rectus abdominis (upper & middle abs), hip flexors, transverse abdominis (deep core stabilizer).
How to do it:
- Lie flat on your back on a mat or soft surface — knees bent, feet flat on the floor hip-width apart.
- Place hands behind your head (elbows wide and pointing out, or lightly touching ears) or cross arms over chest for less neck strain.
- Engage your core by drawing your navel toward your spine and pressing your lower back gently into the floor.
- Lift your shoulders and upper back off the floor, curling up until your shoulder blades clear the mat. Don’t sit fully up; focus on curling your torso.
- Pause for one second at the top and squeeze your abs hard (imagine pulling your ribs toward your hips).
- Slowly lower back down, keeping control and tension in your core.
- Repeat without fully resting at the bottom.
- Sets/Reps: 3 sets of 10–15
Why it works: This classic isolation exercise builds thickness and definition in the rectus abdominis (the “six-pack” muscle), strengthens hip flexors for better leg drive in other moves, and teaches precise core activation and control. While it won’t spot-reduce belly fat, it creates stronger, more visible abs once overall body fat decreases through diet and the challenge’s cardio/strength work.
9. Jump Rope
Muscles Targeted: Calves, quads, glutes, core, shoulders, cardiovascular system
How to do it:
- Stand with feet hip-width apart and imagine holding a jump rope.
- Jump lightly on your feet while making small, quick circles with your wrists (like you’re turning rope).
- Keep your jumps low and quick, and land softly on the balls of your feet to reduce impact.
- Stay upright with your core tight, chest up, shoulders relaxed, and gaze forward.
- Maintain a steady, controlled pace — no wild arm swings; the motion comes from wrists and light bounces.
- Adjust the rope length so the handles reach the armpits when standing on the middle.
- Duration: 3 rounds of 2 minutes with 30–60 second rests.
Why it works: Jump rope is one of the most efficient cardio exercises ever — it burns massive calories in minimal time, dramatically improves coordination, agility, foot speed, and endurance, tones the calves/quads/glutes, engages the core and shoulders for stability, and creates a powerful fat-burning effect through high heart-rate demand and afterburn.
Share this 21 day workout challenge with all your friends. They will thank you later as they burn fat!
