20-minute full-body HIIT workout

About this workout

This 20-minute HIIT workout is designed to maximise calorie burn and build functional strength without any equipment. High-intensity interval training alternates between periods of intense effort and brief recovery, making it one of the most time-efficient ways to exercise.

Workout structure

• Warm-up: 3 minutes
• Main circuit: 15 minutes (3 rounds)
• Cool-down: 2 minutes

Each exercise is performed for 40 seconds, followed by 20 seconds of rest. Complete 3 full rounds of the circuit.

Warm-up (3 minutes)

Perform each movement for 45 seconds:

1. Marching on the spot - Lift knees high, pump arms
2. Arm circles - Large circles, both directions
3. Hip circles - Hands on hips, rotate in both directions
4. Bodyweight squats - Slow and controlled

Main circuit

Exercise 1: Jumping jacks

Duration: 40 seconds on, 20 seconds rest

How to perform:

1. Stand with feet together, arms by your sides
2. Jump feet out wide whilst raising arms overhead
3. Jump feet back together, lowering arms
4. Repeat at a quick, steady pace

Modification: Step out to each side instead of jumping (low impact)

Exercise 2: Push-ups

Duration: 40 seconds on, 20 seconds rest

How to perform:

1. Start in a high plank position, hands slightly wider than shoulders
2. Lower your chest towards the floor, keeping your body in a straight line
3. Push back up to the starting position
4. Keep your core engaged throughout

Modification: Perform on knees or against a wall

Exercise 3: High knees

Duration: 40 seconds on, 20 seconds rest

How to perform:

1. Stand tall with feet hip-width apart
2. Drive one knee up towards your chest
3. Quickly switch legs, pumping your arms
4. Maintain a quick pace, landing softly on the balls of your feet

Modification: March on the spot with high knees (no jumping)

Exercise 4: Squat jumps

Duration: 40 seconds on, 20 seconds rest

How to perform:

1. Stand with feet shoulder-width apart
2. Lower into a squat position, keeping weight in your heels
3. Explode upward, jumping off the ground
4. Land softly, immediately lowering into the next squat

Modification: Regular bodyweight squats without the jump

Exercise 5: Mountain climbers

Duration: 40 seconds on, 20 seconds rest

How to perform:

1. Start in a high plank position
2. Drive one knee towards your chest
3. Quickly switch legs, as if running horizontally
4. Keep your hips low and core tight

Modification: Slow down the pace or step feet in rather than jumping

Cool-down (2 minutes)

Hold each stretch for 20-30 seconds:

1. Standing quad stretch - Pull heel towards glutes
2. Forward fold - Reach towards toes, let head hang
3. Chest opener - Clasp hands behind back, open chest
4. Deep breathing - 5 slow, deep breaths

Tips for best results

• Stay hydrated: Have water nearby and take sips during rest periods if needed
• Focus on form: Quality over speed, especially as you fatigue
• Breathe: Exhale on the effort, inhale on the recovery
• Listen to your body: Take extra rest if needed, but push yourself

Progression

Once this workout feels manageable:

• Increase work intervals to 45 seconds
• Add a 4th round
• Reduce rest periods to 15 seconds
• Add more challenging exercise variations

When to do this workout

This HIIT workout can be done:

• First thing in the morning to boost metabolism
• During a lunch break for an energy boost
• In the evening to relieve stress

Allow at least 48 hours between HIIT sessions for recovery. 2-3 times per week is optimal for most people.