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REHIT: a 10-minute sprint workout on a bike or rower

Short answer: REHIT is about 10 minutes of easy pedaling with two all-out sprints of up to 20 seconds each. In the first study, three sessions a week for six weeks improved aerobic fitness in inactive young adults. You're working hard for about 40 seconds and easy the rest of the time. It works best alongside easy cardio and strength training, not instead of them.

What REHIT means

REHIT stands for reduced-exertion high-intensity interval training. It's a kind of sprint interval training: very short all-out efforts with easy recovery in between. All-out means as hard as you can possibly go, not just hard.

Classic sprint workouts used four to six all-out sprints of 30 seconds, and many people find those brutal. REHIT asks for much less: two sprints of up to 20 seconds in a session of about 10 minutes. The researchers were looking for the least hard exercise that still improves fitness.

What the research found

The first REHIT study came out in 2012, led by Richard Metcalfe. Twenty-nine healthy but inactive young men and women took part. Fifteen did 10-minute sessions on a stationary bike, three times a week for six weeks, and the rest kept their usual routine. Each session was easy pedaling with two all-out sprints (one in the very first session). The sprints lasted 10 seconds in week 1, 15 seconds in weeks 2 and 3, and 20 seconds in the last three weeks.

Aerobic fitness went up by about 15 percent in the men and 12 percent in the women. Insulin sensitivity, a measure of how well the body handles blood sugar, went up by 28 percent in the men (Metcalfe and colleagues, 2012). With 15 people training, it was a small study.

Later, the same researchers argued that workouts with fewer and shorter sprints give health benefits no worse than the classic version (Vollaard and Metcalfe, 2017). A pooled analysis of 38 sprint training studies found that fitness gains weren't smaller when a session had fewer sprints (Vollaard, Metcalfe and Williams, 2017). A 2024 review described REHIT as two or three all-out sprints of 20 to 30 seconds in a 10-minute session, and said it has been shown to improve metabolic and heart health markers (Metcalfe and Vollaard, 2024).

Keep the limits in mind. Most REHIT studies are small and short, and most used bikes. Rowing versions have only been tested in single sessions with active young adults. Those show how the body responds that day, not what happens over months (Clausen and Astorino, 2024, 2026).

A REHIT session on a bike

You need a bike where you can set a heavy resistance quickly, such as a stationary bike with a resistance knob, or an air bike.

  1. Warm up for about 3 minutes of easy pedaling.
  2. Sprint 1: 20 seconds all-out. Turn the resistance up and pedal as hard as you can.
  3. Recover for about 3 minutes of very easy pedaling at low resistance.
  4. Sprint 2: 20 seconds all-out.
  5. Cool down for about 3 minutes of easy pedaling until your breathing settles.

That's about 10 minutes. If you're new to all-out work, start with 10-second sprints and build to 20 over a few weeks, as the first study did.

A REHIT session on a rower

A rowing machine works too, if you already row with good form. All-out rowing takes skill. When you're tired, the stroke can fall apart and strain your back.

  1. Warm up for about 4 minutes of easy rowing. Practice the order of the stroke: legs, then body swing, then arms.
  2. Three sprints of 20 seconds, all-out but with control.
  3. Row very easily for about 3 minutes between sprints.
  4. Cool down for about 2 minutes.

This version takes about 13 minutes. If your form breaks during a sprint, ease off. A clean stroke matters more than the last few seconds.

How often to do it

The first study used three sessions a week. One or two is plenty for most people, especially if you also lift and do easy cardio. Leave at least a full day between all-out sessions.

If you lift, do REHIT after your strength session or on another day. Hard cardio in the hours before a heavy squat or hinge session can hurt your lifting. A pooled analysis of combined training found that the cost to strength gains depended on the type, frequency and length of the cardio, and that running led to clear losses where cycling didn't (Wilson and colleagues, 2012). That research looked at gains over weeks, not the gap within a day, so treat four hours between hard cardio and heavy lifting as a cautious rule of thumb.

What REHIT doesn't replace

  • Easy cardio. US guidelines ask adults for 150 to 300 minutes a week of moderate activity, or 75 to 150 of vigorous activity. Two 10-minute REHIT sessions don't get you there. See How much cardio you need.
  • Strength training. Sprinting doesn't build the strength that lifting does.
  • A fat-loss plan. A 10-minute session burns little energy on its own.

Who should be careful

All-out sprints push your heart rate and blood pressure very high for a short time. If you have heart disease or another health condition, or you get chest pain or unusual breathlessness when you exercise, check with your doctor first. If you've been inactive for a long time, build a few weeks of easy cardio before you sprint.

Stop right away if you feel chest pain, faintness or unwell.

Common mistakes

  • Sprinting at "hard" instead of all-out. REHIT depends on maximal efforts. If you could keep the pace up for a minute, it isn't all-out.
  • Pushing during recovery. The minutes between sprints should be very easy.

For another short, hard format, see Tabata done right.

How Axial Fit does it

  • Bike REHIT and Rowing REHIT, on the clock. Four minutes of easy pedaling or rowing, three all-out sprints with three minutes of very easy work between, and a two-minute cool-down: about 13 minutes. On the bike, turn the resistance up for each sprint and back down for each recovery.
  • Sprints that build up. Your first REHITs use 10-second sprints, then 15, then the full 20, like the first study. After each one it asks, "Could you have done another sprint?" Two sessions at a length without a No move you up. A No keeps you there.
  • Health questions first. REHIT opens once you've answered a short set of yes-or-no health questions. Rowing REHIT also asks you to confirm you can row easily for 10 minutes without pain and keep your form on hard strokes. Every hard session shows one line under End: "Chest pain, faintness or feeling unwell: stop now."
  • Only for gear you have. It suggests REHIT only on a bike or rower you've saved.
  • A day between all-out sessions. It suggests a full day between them and doesn't pick REHIT for you inside that window. In your first two weeks it suggests one hard session a week. If you start one anyway, it tells you once and leaves the choice to you.
  • After strength. When your days are full, it may place REHIT right after a strength session. Hard cardio goes after strength, or at least four hours before it.
  • Honest credit. REHIT counts toward your weekly cardio for its time, with extra credit only for the sprint seconds you actually did.

Sources

  • Metcalfe RS, Babraj JA, Fawkner SG, Vollaard NBJ, 2012. Towards the minimal amount of exercise for improving metabolic health: beneficial effects of reduced-exertion high-intensity interval training. European Journal of Applied Physiology, 112(7), 2767-2775. doi:10.1007/s00421-011-2254-z
  • Vollaard NBJ, Metcalfe RS, 2017. Research into the health benefits of sprint interval training should focus on protocols with fewer and shorter sprints. Sports Medicine, 47(12), 2443-2451. doi:10.1007/s40279-017-0727-x
  • Vollaard NBJ, Metcalfe RS, Williams S, 2017. Effect of number of sprints in an SIT session on change in VO2max: a meta-analysis. Medicine and Science in Sports and Exercise, 49(6), 1147-1156. doi:10.1249/MSS.0000000000001204
  • Metcalfe R, Vollaard N, 2024. Reduced-exertion high-intensity interval training (REHIT): a feasible approach for improving health and fitness? Applied Physiology, Nutrition, and Metabolism, 49(7), 984-992. doi:10.1139/apnm-2024-0024
  • Clausen RD, Astorino TA, 2024. Excess post-exercise oxygen consumption after reduced exertion high-intensity interval training on the cycle ergometer and rowing ergometer. European Journal of Applied Physiology, 124(3), 815-825. doi:10.1007/s00421-023-05309-x
  • Clausen RD, Astorino TA, 2026. Lower blood lactate concentration and more positive affective valence in response to reduced exertion high intensity training (REHIT) on the rowing ergometer compared to cycle ergometry. Perceptual and Motor Skills, 133(2), 495-509. doi:10.1177/00315125251352652
  • Wilson JM, Marin PJ, Rhea MR, Wilson SM, Loenneke JP, Anderson JC, 2012. Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research, 26(8), 2293-2307. doi:10.1519/JSC.0b013e31823a3e2d
  • US Department of Health and Human Services, 2018. Physical Activity Guidelines for Americans, 2nd edition. odphp.health.gov