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The Definitive Guide To High Intensity Interval Training (HIIT)


The Definitive Guide To High Intensity Interval Training (HIIT)

What is HIIT, Why it works and How does it benefit the body?

Long gone are the days when working hard was deemed as a desirable virtue. The schedules of today call out for smart work. Why not stop killing ourselves by training more and devoting the time saved, to our families?And in this journey, HIIT (High Intensity Interval Training) can be your go-to training program.

What is HIIT?

Known by a variety of names that include Wind Sprints, High Intensity Intermittent Exercise (HIIE) or Sprint Interval Training (SIT), and catchy names like Body for Life workout, HIIT is an enhanced form of interval exercise. The intervals are basically alternating periods of workout – Short and intense, spaced by Long and less intense. The lesser intense period or the recovery period, is usually called EPOC or Excess Post-exercise Oxygen Consumption.

You can opt to simply do exercises such as burpees; but if you want to add a little more challenge to your routine, then it is wise to add HIIT equipment such as a kettlebell to your exercises.

The Strategy Behind: Maximum output in limited time [1]

USP: Fast paced, non-stereotypical, no equipment necessary

Background: It was developed during the 70s by track coaches to prepare runners for greater efficiency. In those days people knew it by the name of Fartlek” training, which stood for Speed Play  in Swedish.

Over the time, four kinds of regimen have been developed independently by various coaches and hence the names, Peter Coe regimen, Tabata regimen, Gibala regimen, Timmons regimen, though the results are almost same.

Exercise Session of HIIT

An ideal session of 4-30 mins comprises of warm up, 3-10 reps of high intensity workout (90% of heart capacity) of  30-40 seconds duration. The reps are separated by periods of medium intensity workout (50% of heart capacity) of 15-20 seconds duration. The closing ceremony is of course a 5 minutes cool down phase. Beginning with a ratio of 4:1, athletes gradually advance to 2:1 ratio of work to rest.

Though after the intense session you’ll not feel like cutting up on the recovery period, but still, its my duty to remind you not to over-train yourself. Recovery period is utterly crucial as this is the time your body needs to replenish lost oxygen. Precisely that’s why your heart rate is still hyped up when you are recovering from an intense workout.

People call it an advanced level of aerobic exercise but ever wondered what they mean by that?

Well, our body has two kinds of energy systems – Aerobic and Anaerobic. Similarly, muscles are also of two types – Slow twitch (aerobic) and Fast twitch (anaerobic). In usual cardio workouts, slow twitch muscles are trained. But we never push our limits to anaerobic, ignoring the fast twitch muscles and that exactly makes all the difference.

When you train with HIIT, aerobic system provide energy first but it gets depleted very fast due to the high intensity. As a result, anaerobic system gets down to work and lends energy as a debt to the aerobic system. In the process, you are training your fast twitch muscles which in return raises your endurance level.

So, when you are in the recovery period, your body is still burning calories to replenish the debt and hence, your heart rate is still on a high.

Evidently, its like a quick way to get fit, though not an easy quick way.

Who should do it : Only those people whose primary concern is boosting cardiovascular fitness and endurance without the loss of lean muscle mass they already have. With that I’m already assuming you are able to exercise 20-30 minutes continuously to upto 70% of your estimated maximum heart rate. If not, please get your requisites in place first.

Who should not do it :

  • Folks suffering from cardiovascular problems or
  • Health concerns (physical) that could limit their ability to exercise at very intense levels
  • People new to aerobic exercise or not in good shape already

If you fall into any of these categories then, HIIT is not for you—at least not for now. For any doubts, you must always consult your physician first.

General guidelines

  • Always warm up and cool down for at least 5 minutes
  • A burning sensation in your muscles will serve as an indicator of entry into anaerobic zone
  • In case of chest pains or breathing difficulties, cool down immediately but don’t stop or else you might faint due to a sudden shock
  • HIIT should only be done twice in a week and never more than that
  • Your diet must have 20% carb content to be able to generate energy for the intense sessions
  • Weight workouts: Your weight workouts must not be very heavy and voluminous if you are going for HIIT
  • Don’t go for it if your primary goal is to lose body fat
  • Make sure you have a good recovery system

You can find some beginner workout routines from here.

Isn’t it another name of CrossFit Training?

NO! Four major points that make HIIT different from CrossFit are:

  1. No weights in HIIT (usually), as the regime comprises of sprints, spinning, burpees and like, when on the other hand CrossFit is a combination of Weightlifting and Gymnastics.
  2. HIIT is not random unlike CrossFit where you get a new Workout Of Day for every session.
  3. HIIT has programmed resting periods while in CrossFit, its more like a race against time.
  4. HIIT does more good to Weightlifters than CrossFit since CrossFit involves usage of weights mainly.

Benefits of HIIT

1. Intermittent sessions with high and low intensity help develop focus.

2. Extremely time efficient as training time reduces to half with a positive influence on the outcome.

3. Increased VO2 or maximum volume of oxygen that the body can absorb due to anaerobic sessions incorporated. [2]

4. Boosts fatigue resistance in slow twitch muscles and has positive impact on activation speed of fast twitch muscles. As a result, overall muscle endurance gets boosted. [3]

5. You feel younger inside out. Due to HIIT, Human Growth Hormone levels get increased by 450%, a hormone that not only controls metabolism but also takes care of ageing. [4]

6. Since you rarely require any gym or equipment, you can do it almost anywhere.

7. No bulking up, only an athletic built. Are the ladies listening?!

8. Enhanced lactate potential of the muscles. Lactate potential refers to how fast the body is able to remove the waste of lactic acid produced during exercise which is linked directly to higher endurance levels.

9. Decreased risk of cardiovascular disorders. [5]

10. Fat loss and a leaner fit body. [6]

11. Improved skeletal muscle metabolism [7] and improved insulin action. [8]

12. An all round fit body with much better results in lesser time. [9]

There are multiple workouts to choose from when it comes to high interval training. For starters, you may consider jogging for 10 minutes to elevate your heart rate followed by workouts with multiple reps per exercise. You can do exercises like semi-stiff legged dumbbell deadlifts, thruster, elevated leg push-ups, kettlebell swings, and kipping pull-ups.


[1] Metcalfe RS, Babraj JA, Fawkner SG, Vollaard NB. Towards the minimal amount of exercise for improving metabolic health: beneficial effects of reduced-exertion high-intensity interval training. Eur J Appl Physiol. 2012 Jul;112(7):2767-75. doi: 10.1007/s00421-011-2254-z. Epub 2011 Nov 29. PMID: 22124524

[2] Tabata I, Nishimura K, Kouzaki M, Hirai Y, Ogita F, Miyachi M, Yamamoto K. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Med Sci Sports Exerc. 1996 Oct;28(10):1327-30. PMID: 8897392

[3] Martin J. Gibala, Jonathan P. Little, Martin van Essen, Geoffrey P. Wilkin, Kirsten A. Burgomaster, Adeel Safdar, Sandeep Raha and Mark A. Tarnopolsky. Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. doi: 10.1113/jphysiol.2006.112094. Sept, 2006 The Journal of Physiology, 575, 901-911.

[4] Stokes KA, Nevill ME, Hall GM, Lakomy HK. The time course of the human growth hormone response to a 6 s and a 30 s cycle ergometer sprint. J Sports Sci. 2002 Jun;20(6):487-94. PMID: 12137178

[5] Buchan DS, Ollis S, Young JD, Thomas NE, Cooper SM, Tong TK, Nie J, Malina RM, Baker JS. The effects of time and intensity of exercise on novel and established markers of CVD in adolescent youth. Am J Hum Biol. 2011 Jul-Aug;23(4):517-26. doi: 10.1002/ajhb.21166. Epub 2011 Apr 4. PMID: 21465614

[6] Trapp EG, Chisholm DJ, Freund J, Boutcher SH. The effects of high-intensity intermittent exercise training on fat loss and fasting insulin levels of young women. Int J Obes (Lond). 2008 Apr;32(4):684-91. doi: 10.1038/sj.ijo.0803781. Epub 2008 Jan 15. PubMed PMID: 18197184.

[7] Tremblay A, Simoneau JA, Bouchard C. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994 Jul;43(7):814-8. PMID: 8028502

[8] Babraj JA, Vollaard NB, Keast C, Guppy FM, Cottrell G, Timmons JA. Extremely short duration high intensity interval training substantially improves insulin action in young healthy males. BMC Endocr Disord. 2009 Jan 28;9:3. doi: 10.1186/1472-6823-9-3. PubMed PMID: 19175906; PubMed Central PMCID: PMC2640399.

[9] Stephen H. Boutcher. High-Intensity Intermittent Exercise and Fat Loss. J Obes. 2011; 2011: 868305. Published online 2010 November 24. doi: 10.1155/2011/868305 PMCID: PMC2991639