Usually the recommendations for HIIT workouts involve 20 second high intensity work followed by an equivalent or greater rest period. Or Tabata, which invoves 20 second work followed by a 10 second rest.

Would it still be considered HIIT if you are working at >95% HR for 4-5min, then rest for a couple of minutes, and repeat for several cycles? I read everywhere that if you can keep going for more than a minute then it's not really hugh intensity, but what if my heart monitor marks more than 95% for a continuous 5 minutes or more?

  • It seems unlikely that you can got that hard for that long. Are you sure the monitor is accurate? Commented Jun 3, 2014 at 20:13
  • 2
    where is the 95% coming from? Is this based on your gender/age etc or have you measured your own 100%?
    – Luis
    Commented Jun 3, 2014 at 21:47
  • 2
    If you are using 220-age, that is one of the worst myths in exercise science. Don't do that.
    – JohnP
    Commented Jun 4, 2014 at 18:31
  • I suggest you study up on the science of running to get a perspective on what's possible for the human body. Running at ">95% HR for 4-5min" is not only imprecise, but—as others have suggested—very unlikely. Commented Jul 4, 2014 at 8:34

2 Answers 2


What are your goals?

My experience (anecdotal and exercise physiology knowledge) says that for more broad ranging adaptions, 4-6 minute intervals are superior to very short term (i.e. 20 seconds).

6 minute intervals (at the highest relative intensities you would be able to maintain) largely stimulate both anaerobic (first 2-3 min) and aerobic pathways (last 2 -4 min).

Benefits of anaerobic training: Large glycolytic rates, adrenaline response, etc... which also help burn fatty acids post-workout.

Benefits of aerobic training: Improved cardiovascular conditioning, ability to burn more calories, improves ratio of calories burned from fat vs. carbs at given work rate.

Tabata intervals provide some of the former, but not much of the latter.

  • 1
    If I'm not mistaken, you're mixing something up. For one, anaerobic conditioning will probably come after some hard exercise, as aerobic is the default state and anaerobic kicks in when you're running out of oxygen...
    – Luis
    Commented Jun 4, 2014 at 5:23
  • Relative to intensity - 1) lowest intensities oxidize fat 2) 2nd lowest oxidize glycogen (carbs) 3) 2nd highest anaerobically break down glycogen 4) Highest intensities utilize ATP-Creatine Phosphate system. However, at a given intensity, the body will relatively utilized the anaerobic components more initially, and the aerobic components more as time goes by. When you jump on a treadmill at 12mph, initially your heartrate (i.e. aerobic energy usage) is low, but then over minutes ramps up (higher aerobic energy usage). That initial deficit is covered by anaerobic pathways.
    – Ze Apelido
    Commented Jun 4, 2014 at 17:11

Your body doesn't respond to numbers. Tabata and other HIIT exercises are meant to exhaust you faster than that; assuming you want to get the benefit from these and not just 'do' them you might need to find a way to increase intensity such that 4-5 minutes of continuous activity is simply not possible. Those 10 second breaks should quickly become something you are really looking forward to.

The most important take-away here is you should not live and die by an HR monitor, they can be useful but they don't provide the full picture. Also, do double check where these numbers are coming from, they sound awfully suspicious.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.