Cardio and running
HIIT Workout: 5 Routines, How Often and What It Really Does
Published October 20, 2026
A HIIT (high-intensity interval training) workout alternates short bursts of hard effort, typically 20 seconds to 4 minutes, with easier recovery periods, for a total of 10 to 25 minutes. Two to three sessions a week improve cardiovascular fitness (VO2 max) at least as well as longer moderate cardio and lead to similar fat loss in less time.
HIIT became famous for being efficient, then infamous for being overdone. Here's what the research shows, five routines to choose from, and how to fit HIIT into a week without wrecking your recovery.
What the research shows
- Same adaptations, less time. Gibala and colleagues (2006) showed that 2 weeks of sprint interval training (about 2.5 hours in total) produced muscle and performance adaptations similar to traditional endurance training (about 10.5 hours).
- VO2 max. A 2015 meta-analysis by Milanović and colleagues found that HIIT improved VO2 max more than continuous endurance training in healthy young-to-middle-aged adults. See VO2 max.
- Fat loss. Wewege and colleagues (2017) found HIIT and moderate continuous training produced similar reductions in body fat, with HIIT taking about 40 percent less time.
So HIIT isn't magic for fat burning, but it's a powerful, time-efficient tool for fitness.
How hard is "high intensity"?
| Method | Target during work intervals |
|---|---|
| Heart rate | 85-95% of max heart rate (heart rate zones) |
| Perceived effort | 8-9 out of 10: you can't say more than a few words |
| Sprint intervals | All-out (only short efforts of 10-30 s) |
Routine 1: Beginner (walk/jog or bike) — 20 minutes
- 5 min easy warm-up
- 6 x (1 min hard / 2 min easy)
- 5 min easy cool-down
Routine 2: Bodyweight HIIT at home — 16 minutes
Tabata-style: 20 s work / 10 s rest x 8 = 4 minutes per block; 4 blocks with 1 minute rest between.
| Block | Exercise |
|---|---|
| 1 | Jumping jacks or step jacks |
| 2 | Squat (or jump squat) |
| 3 | Mountain climbers |
| 4 | Burpees (or step-back burpees) |
Note: true "Tabata" protocols were all-out cycling sprints. At home, most people work at a hard but sustainable level.
Routine 3: Norwegian 4x4 (running, rowing or cycling) — 35 minutes
- 10 min warm-up
- 4 x (4 min at ~85-95% HRmax / 3 min active recovery)
- 5 min cool-down
A classic for improving VO2 max.
Routine 4: Sprint intervals — 20 minutes (advanced)
- 10 min warm-up
- 6 x (20-30 s all-out sprint / 2-4 min very easy)
- Cool-down
Best on a bike, rower or hill to reduce injury risk.
Routine 5: Strength-cardio circuit — 20 minutes
EMOM (every minute on the minute) for 20 minutes, alternating:
- 12 kettlebell or dumbbell swings
- 10 push-ups
- 15 air squats
- 12 alternating reverse lunges
- 30 s rest
How often?
| Level | HIIT sessions per week | Other training |
|---|---|---|
| Beginner | 1 | 2-3 strength sessions + walking |
| Intermediate | 2 | Strength + easy cardio |
| Advanced | 2-3 | Plan around heavy leg days |
Most of your cardio should still be easy. Endurance athletes typically do around 80 percent of training at low intensity (Seiler, 2010). HIIT is the spice, not the meal.
Safety
- Warm up properly (warm-up exercises).
- Start with low-impact options (bike, rower, incline walking) if you're heavy, older or have joint issues.
- Talk to your doctor first if you have heart disease, high blood pressure, are over 50 and inactive, or have chest pain, dizziness or unusual breathlessness during exercise.
HIIT for weight loss
HIIT helps, but the calorie deficit does the heavy lifting. Combine 1 to 2 HIIT sessions with daily walking (walking for weight loss) and strength training.
Next steps
Runners can build HIIT into couch to 5k or a 10k training plan. For a 12-week plan that combines strength and conditioning (including sports preparation), see our programme.
Frequently asked questions
Is HIIT better than cardio?
HIIT improves fitness in less time and is excellent for VO2 max. Moderate cardio is easier to recover from and do daily. For fat loss, both lead to similar results when calories are controlled. A mix works best.
Can I do HIIT every day?
Not at true high intensity. Two to three sessions a week with easier days in between allow recovery. Daily walking or easy cycling complements HIIT.
How long should a HIIT session be?
The hard intervals usually add up to 4 to 20 minutes, so sessions including warm-up and cool-down last 15 to 35 minutes.
Is HIIT safe for beginners?
Yes, if you start with low-impact equipment (bike, rower, brisk uphill walking), moderate intensity and few intervals. Increase difficulty gradually and get medical clearance if you have health conditions.
Does HIIT burn fat after exercise?
HIIT slightly increases calorie burn for a while after exercise (often called EPOC), but the extra amount is modest. The main benefit is fitness and the calories burned during the session.
Can I combine HIIT and strength training?
Yes. Do them on separate days, or place HIIT after upper-body sessions. Avoid hard HIIT right before heavy leg training.
Studies cited
- Gibala MJ et al. (2006). Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. The Journal of Physiology. doi:10.1113/jphysiol.2006.112094
- Milanović Z, Sporiš G, Weston M (2015). Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials. Sports Medicine. doi:10.1007/s40279-015-0365-0
- Wewege M et al. (2017). The effects of high-intensity interval training vs. moderate-intensity continuous training on body composition in overweight and obese adults: a systematic review and meta-analysis. Obesity Reviews. doi:10.1111/obr.12532