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Thursday 5 April 2012

b. Some definitions to understand the Tabata training


Before talking about Tabata training, you need to have some basic understanding about some definitions.

                                          i.    Interval training

Interval training is a type of physical training that involves bursts of high intensity work. This high intensity work is alternated with periods of rest or low activity, the eponymous intervals.




A workout session that involves repeated short, fast-paced bouts of exercise separated by short rest intervals.




This a combination of high intensity exercise followed by a period of low intensity activity (rarely complete rest).




                                         ii.    HIIT

This type of exercise aims to focus on cardio training. High Intensity Interval Training is based on alternate of short, extremely intense intervals with recovery intervals. The ratio between effort and recovery is usually 1:2 (ie you recover twice the time of intense effort). Recovery period can be total rest, or continuing the exercise with low intensity. For example, if you perform sprints, the recovery period can be done by running very slowly. A HIIT session lasts for 10-30 minutes. Above, it’s hard to maintain a sufficient intensity, and it becomes more “interval training”. Some extreme HIIT, like TABATA, can be performed in just 4 minutes, with a ratio 2:1 (twice the time for intense exercise compared to rest intervals).

For instance, you can sprint two series of 5 prints, at 85-90% of your maximum speed, for 30 s. In between intervals, you can rest by walking 30s to 60s. This type of sessions is supposed to be exhausting, therefore at the end of the interval bouts you should be out of breath and your heart should pump hard.

Because of its intensity, for beginners, a progressive and adaptive period must be carefully scheduled. You need at least 3 or 4 sessions to adjust the intensity of efforts and the duration of bouts. Compared to continuous endurance training, it is proven that HIIT or HIIE (High Intensity Intermittent Exercise) improve performance and improve capacity of the muscles to burn extra fat. (source: http://www.ncbi.nlm.nih.gov/pubmed/21113312)

So, basically, the difference between interval training and HIIT is that the intensity is higher and the recovery period ratio is smaller.

If you do 10x400m running at 90% intensity (VO2max) with 1mn rest, it’s interval training.

If you do 8x100m running at 150% intensity (VO2max) with less than 30s rest, it’s HIIT.





                                        iii.    EPOC

After cardiovascular exercise or weight training, the body continues to need oxygen at a higher rate than before the exercise began. This sustained oxygen consumption is known as “Excess Postexercise Oxygen Consumption” (EPOC). Originally referred to as an oxygen debt, this postexercise state was first hypothesized by A.V. Hill and H. Lupton in 1922. Hill and Lupton theorized that the body needs to replace the oxygen used by working muscles during mild to intense bouts of exercise. More recently, researchers have used the term EPOC to describe the several different events that occur as the body restores itself to homeostasis, or rest. During EPOC the body is restoring itself to its pre-exercise state, and thus is consuming oxygen at an elevated rate. This means that energy is also being expanded at an elevated rate.


In recovery, oxygen (EPOC) is used in the processes that restore the body to a resting state and adapt it to the exercise just performed. These include: hormone balancing, replenishment of fuel stores, cellular repair, innervation and anabolism.

EPOC is accompanied by an elevated consumption of fuel. In response to exercise, fat stores are broken down and free fatty acids (FFA) are released into the blood. In recovery, the direct oxidation of free fatty acids as fuel and the energy consuming re-conversion of FFA's back into fat stores both take place.


                                       iv.    VO2max

VO2 max (also maximal oxygen consumption, maximal oxygen uptake, peak oxygen uptake or aerobic capacity) is the maximum capacity of an individual's body to transport and use oxygen during incremental exercise, which reflects the physical fitness of the individual.


Vo2 Max - maximum oxygen uptake (Engine Size - how big is the engine?) This is the ability of the circulatory system to transport oxygen and of the muscular system to extract and use oxygen. Vo2 max is an excellent indicator of aerobic fitness, but a poor predictor of performance within a homogenous group of athletes.

MAX VO2 functionally represents the maximum amount of oxygen that can be removed from circulating blood and used by the working tissues during a specified period. World class endurance athletes generally have high readings.

Maximum Oxygen Update (Max VO2) values for selected groups and individuals are as follows:

General Population, Female, Aged 20-29: 35-43 ml/kg/min

General Population, Male, Aged  20-29:    44-51

US College Track, Male:                             57.4

College Students, Male:                             44.6

Highest Recorded Female (Cross-Country Skier): 74

Highest Recorded Male (Cross-Country Skier):  94




VO2 max is greatly limited by genetics, but still can be improved up to 20%, maybe 30% in extreme cases  (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2991639/table/tab1/)



                                        v.    MAS or MAV

Maximal Aerobic Velocity (MAV) or MAS (Speed) is the speed of movement at which one reaches 100% oxygen consumption (VO2max). Usually, you can sustain this pace for 4mn to 8mn. This is pretty easy to measure when you run, or cycle, or perform rowing. For weight circuit training or cardio strength resistance, it’s become harder to evaluate. However, with a portable heart monitor (type polar), you can have a good estimation of the intensity you are working out. 

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