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25 Minute Intermediate HIIT Workout

A fast-paced, equipment-free HIIT session with intervals, core work, and a short cool-down.

Warm-Up

Raise heart rate and prep joints for faster movement. 5 min.

Jumping Jack
Jumping Jack1 min
How to

A full-body cardio move that trains coordination, calves, shoulders, and hips.

  1. Stand tall with feet together and arms at your sides.
  2. Jump your feet out as you raise your arms overhead.
  3. Jump your feet back together as you lower your arms.
  4. Repeat at a steady pace, landing softly each time.
Form cues
  • Stay light on your toes
  • Keep your chest tall
Common mistakes
  • Landing hard with locked knees
  • Letting your arms swing out of control
High Knees
High Knees1 min
How to

A fast marching or running move that raises each knee to train your legs and raise your heart rate.

  1. Stand tall with feet under your hips and arms at your sides.
  2. Drive one knee up toward hip height as the opposite arm swings forward.
  3. Land softly on the ball of that foot.
  4. Switch quickly to the other knee and keep alternating.
  5. Keep a steady rhythm until the set ends.
Form cues
  • Stay tall through your chest
  • Land light and quick
Common mistakes
  • Leaning back as your knees lift
  • Stomping your feet into the floor
Inchworm
Inchworm1 min
How to

A full-body walkout that trains your core, shoulders, and hamstrings.

  1. Stand tall with feet hip-width apart.
  2. Hinge at your hips and place your hands on the floor.
  3. Walk your hands forward to a high plank.
  4. Pause with your body in a straight line.
  5. Walk your hands back to your feet and stand up.
Form cues
  • Brace your core in the plank.
  • Keep your legs as straight as you can.
Common mistakes
  • Letting your hips sag in the plank.
  • Rushing the hand walkout.
Bodyweight Squat
Bodyweight Squat1 min
How to

A bodyweight lower-body move that trains your quads, glutes, and hips.

  1. Stand with feet about shoulder-width apart and toes slightly out.
  2. Brace your core and keep your chest tall.
  3. Bend your knees and hips to lower into a squat.
  4. Push through your feet to stand back up.
Form cues
  • Keep your knees tracking over your toes
  • Keep your chest up
Common mistakes
  • Letting your knees cave in
  • Rounding your back as you lower
Push Up
Push Up1 min
How to

A bodyweight press that trains your chest, shoulders, triceps, and core.

  1. Start in a high plank with hands just wider than shoulders.
  2. Brace your core and keep your body in a straight line.
  3. Bend your elbows and lower your chest toward the floor.
  4. Press the floor away until your arms are straight again.
  5. Repeat for your reps.
Form cues
  • Keep your ribs down
  • Move your body as one piece
Common mistakes
  • Letting your hips sag
  • Flaring your elbows straight out

Circuit A

40s on / 20s off. Move quickly between exercises; use the 20s to breathe and reset.

Burpee
Burpee40 sec
How to

A full-body bodyweight move that combines a squat, plank, push-up, and jump to train power and conditioning.

  1. Stand with feet about hip-width apart and arms at your sides.
  2. Squat down and place your hands on the floor.
  3. Jump or step your feet back to a strong plank.
  4. Lower your chest toward the floor, then press back up.
  5. Jump or step your feet back in and stand tall.
  6. Jump up with arms overhead, then land softly and repeat.
Form cues
  • Brace before you jump back.
  • Land with soft knees.
Common mistakes
  • Letting your hips sag in the plank.
  • Crashing down into the floor.
Bodyweight Squat
Bodyweight Squat40 sec
How to

A bodyweight lower-body move that trains your quads, glutes, and hips.

  1. Stand with feet about shoulder-width apart and toes slightly out.
  2. Brace your core and keep your chest tall.
  3. Bend your knees and hips to lower into a squat.
  4. Push through your feet to stand back up.
Form cues
  • Keep your knees tracking over your toes
  • Keep your chest up
Common mistakes
  • Letting your knees cave in
  • Rounding your back as you lower
Push Up
Push Up40 sec
How to

A bodyweight press that trains your chest, shoulders, triceps, and core.

  1. Start in a high plank with hands just wider than shoulders.
  2. Brace your core and keep your body in a straight line.
  3. Bend your elbows and lower your chest toward the floor.
  4. Press the floor away until your arms are straight again.
  5. Repeat for your reps.
Form cues
  • Keep your ribs down
  • Move your body as one piece
Common mistakes
  • Letting your hips sag
  • Flaring your elbows straight out
3 rounds · 20 sec rest
1 min rest

Circuit B

40s on / 20s off. Keep your core braced; prioritize quality reps over speed.

Mountain Climber
Mountain Climber40 sec
How to

A fast plank move that trains your core, shoulders, and hip flexors.

  1. Start in a high plank with hands under shoulders and legs straight.
  2. Brace your core and keep your body in a straight line.
  3. Drive one knee toward your chest, then quickly step it back.
  4. Alternate knees at a steady pace for the set.
Form cues
  • Keep your hips low
  • Push the floor away
Common mistakes
  • Letting your hips bounce high
  • Dropping your head or rounding your shoulders
Alternating Reverse Lunge
Alternating Reverse Lunge40 sec
How to

A stepping lunge that trains your legs and glutes while challenging balance.

  1. Stand tall with your feet hip-width apart.
  2. Step one foot back and lower until both knees bend.
  3. Push through your front foot to stand back up.
  4. Repeat on the other side, alternating each rep.
Form cues
  • Keep your chest tall
  • Front knee tracks over toes
Common mistakes
  • Leaning forward as you lower
  • Letting your front knee cave inward
Plank
Plank40 sec
How to

A core hold that trains your abs, shoulders, and glutes while you keep a straight body line.

  1. Place your forearms on the floor with elbows under shoulders.
  2. Step both feet back and lift into a straight line from head to heels.
  3. Brace your abs and squeeze your glutes.
  4. Hold the position and breathe steadily.
  5. Lower your knees to the floor to finish.
Form cues
  • Keep your ribs pulled down
  • Push the floor away
Common mistakes
  • Letting your hips sag
  • Lifting your hips too high
3 rounds · 20 sec rest

Cool-Down

Bring breathing down and open up hips, quads, and chest. 2 min.

Child's Pose
Child's Pose40 sec
How to

A kneeling rest stretch that relaxes your back, hips, and shoulders while you breathe.

  1. Kneel with your big toes together and knees apart.
  2. Sit your hips back toward your heels.
  3. Reach your arms forward and lower your chest to the floor.
  4. Rest your forehead down and relax your neck.
  5. Hold the stretch and breathe slowly.
Form cues
  • Let your hips sink back
  • Keep your neck relaxed
Common mistakes
  • Forcing your hips down
  • Holding your breath
Standing Quad Stretch
Standing Quad Stretch40 sec each side
How to

A standing thigh stretch that targets the front of your hip and quad on one leg.

  1. Stand tall and hold a wall or chair for balance if needed.
  2. Bend one knee and hold your ankle or foot behind you.
  3. Keep your knees close and gently draw your heel toward your glute.
  4. Hold the stretch and breathe slowly.
  5. Release with control, then switch legs.
Form cues
  • Stand tall through your chest
  • Keep your knees close
Common mistakes
  • Arching your lower back
  • Pulling the knee out to the side
Chest Opener Stretch
Chest Opener Stretch40 sec
How to

A standing stretch that opens your chest and shoulders with a steady hold.

  1. Stand tall with your feet hip-width apart.
  2. Clasp your hands behind your back or hold a towel.
  3. Gently straighten your arms and lift your chest.
  4. Hold the stretch and breathe slowly.
  5. Release your hands and relax your shoulders.
Form cues
  • Keep your ribs down
  • Lift through your chest
Common mistakes
  • Arching your lower back
  • Forcing your arms too high
Compound Moves That Spike Your Heart Rate

Compound Moves That Spike Your Heart Rate

Burpees, mountain climbers, and high knees recruit full-body musculature while demanding rapid ATP-PC and glycolytic energy system output, maximizing caloric burn in minimal time. Push-ups and squats anchor the session with compound strength stimulus, ensuring you build muscle while conditioning your cardiovascular system simultaneously.

What HIIT Actually Demands From Your Body

What HIIT Actually Demands From Your Body

Intermediate HIIT exposes your anaerobic threshold repeatedly, forcing your cardiovascular system to recover under fatigue — the exact stress that elevates post-exercise oxygen consumption (EPOC) for hours after training. The inchworm and alternating reverse lunge demand hip flexor mobility and single-leg stability, two limiting factors that separate intermediate athletes from beginners.

Structure Built Around Work-to-Rest Ratios

Structure Built Around Work-to-Rest Ratios

The 18-minute main block uses interval sequencing to progressively load your system before the dead bug and glute bridge shift focus to posterior chain and deep core stabilization — preventing compensation patterns that develop when global fatigue sets in. To personalize intensity, shorten rest intervals by 5 seconds each week to drive progressive overload without adding a single extra rep.

25 Minute Intermediate HIIT Workout | Mighty Nimble | Mighty Nimble