3-Day HIIT Circuit

Overview

HIIT (High-Intensity Interval Training) circuits alternate short bursts of maximum effort with brief rest periods. This format keeps heart rate elevated throughout, creating significant calorie burn both during and after sessions (the EPOC effect). Three days per week is enough to drive fat loss without burning out — rest days allow the body to recover and adapt.

This programme is suitable for complete beginners with reasonable cardiovascular fitness, and intermediates who want variety. If you struggle to complete the first week, rest for longer between exercises — do not sacrifice form for pace.

Schedule

Warm-Up Protocol

Never skip the warm-up before HIIT — jumping straight into high-intensity work without preparation significantly increases injury risk. 5 minutes of brisk walking, then jogging on the spot (30 seconds), arm circles, leg swings, and 5 squat thrusts before starting.

Week 1–4: Foundation Circuits

Each circuit: perform each exercise for 40 seconds, rest 20 seconds between exercises. Complete 3 rounds with 90 seconds rest between rounds.

Day 1: Circuit A — Lower Body Emphasis

Day 2: Circuit B — Upper Body Emphasis

Day 3: Circuit C — Full Body

Week 5–8: Intensification Phase

Increase to 4 rounds per circuit. Reduce rest between exercises from 20 seconds to 15 seconds. Increase work intervals from 40 to 45 seconds. Replace standard burpees with burpee broad jumps for extra intensity.

Week 7–8: Advanced Version

Add a 4th round and reduce between-round rest to 60 seconds. Swap any exercise you find easy for a harder variation (e.g., regular push-up → clap push-up, squat jump → tuck jump).

Progression

HIIT progression is measured in rounds, work-to-rest ratios, and exercise difficulty. Each week, aim to push slightly harder during the 40-second work windows — every session should be uncomfortable but completable. Resting mid-set is fine; stopping the clock is not.

Cutting Modifications

HIIT is already optimised for cutting — high calorie burn per session. On a cut, the most important modification is to ensure adequate carbohydrates before HIIT sessions (20–30g of fast carbs 30–45 minutes before training). Fasted HIIT sounds efficient but leads to suboptimal performance and may increase muscle protein breakdown. Reduce to 3 rounds if energy is very low rather than skipping sessions entirely.