Effects of Moderate-Intensity Endurance and High-Intensity Intermittent Training on Anaerobic Capacity and VO2 Max
Title and Abstract
Tabata I. et. al. Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Med Sci Sports Exerc. (1996) 28(10):1327-30.
This study consists of two training experiments using a mechanically braked cycle ergometer. First, the effect of 6 wk of moderate-intensity endurance training (intensity: 70% of maximal oxygen uptake (VO2max), 60 min.d-1, 5 d.wk-1) on the anaerobic capacity (the maximal accumulated oxygen deficit) and VO2max was evaluated. After the training, the anaerobic capacity did not increase significantly (P > 0.10), while VO2max increased from 53 +/- 5 ml.kg-1 min-1 to 58 +/- 3 ml.kg-1.min-1 (P < 0.01) (mean +/- SD). Second, to quantify the effect of high-intensity intermittent training on energy release, seven subjects performed an intermittent training exercise 5 d.wk-1 for 6 wk. The exhaustive intermittent training consisted of seven to eight sets of 20-s exercise at an intensity of about 170% of VO2max with a 10-s rest between each bout. After the training period, VO2max increased by 7 ml.kg-1.min-1, while the anaerobic capacity increased by 28%. In conclusion, this study showed that moderate-intensity aerobic training that improves the maximal aerobic power does not change anaerobic capacity and that adequate high-intensity intermittent training may improve both anaerobic and aerobic energy supplying systems significantly, probably through imposing intensive stimuli on both systems.
Background
In recent years, training and the Internets have become interval crazy. Everybody wants to do nothing but interval training all the **** time (with some even proclaiming that any non-interval training is not only useless but downright detrimental).
Now, I’ve written extensively about this in what must be about a 12 part series on Steady State vs. Interval Training here on the site. I’m not going to rehash the entirety of that series, mind you; go read it. But simply, both intervals and steady state have their place in training. Arguments that one is inherently or always superior to the other has more to do with marketing than reality.
But among other aspects of this particular meme, the idea of the Tabata protocol (often abbreviated Tabatas) gets bandied about all the time. And the problem is that people are using the term to describe something that they don’t really understand. What has happened is that a bunch of people who don’t really know what they are talking about have written so much about the protocol that what it actually is or accomplishes has been completely diluted.
So I figured I’d undilute it by actually examining the study that the whole set of claims and supposed ‘protocols’ are based on. Because, as is so often the case, what people think they are doing as ‘Tabatas’ are nothing like what the actual study did. And most people who think they are doing the Tabata protocol are doing absolutely nothing of the sort.
As a bit of history, the protocol was actually originally developed by a Japanese speed skating coach and later studied by researchers; I bring this up because speed skating is actually a very peculiar sport in a lot of ways (something that I have insight into as I’ve spent the last 5 years training full time as a skater). But I’m not going to get that into detail here; I simply mention it for completeness.
The Study
The study set out to compare both the anaerobic and aerobic adaptations (in terms of one parameter only, VO2 max) to two different protocols of training. The study recruited 14 active male students who were, at best moderately trained (VO2 max was roughly 50 ml/kg/min which is average at best; elite endurance athletes have values in the 70-80 range).
All work including the pre- and post tests were done on a mechanically braked bicycle ergometer; this is an important point that is often ignored and I’ll come back to in the discussion. Every test or high-intensity workout was proceeded by a 10 minute warm-up at 50% of VO2 max (This is maybe 60-65% maximum heart rate).
The two primary tests were VO2 max and the maximal accumulated oxygen deficit (this is a test of anaerobic capacity, basically people with higher anaerobic capacity can generate a larger oxygen deficit) and then subjected to one of two training programs.
The first program was a fairly standard aerobic training program, subjects exercised 5 days/week at 70% of VO2 max for 60 minutes at a cadence of 70 RPMs for 6 straight weeks. The intensity of exercise was raised as VO2 max increased with training to maintain the proper percentage. VO2 max was tested weekly in this group and the maximal accumulated oxygen deficit was measured before, at 4 weeks and after training.
The second group performed the Tabata protocol. For four days per week they performed 7-8 sets of 20 seconds at 170% of VO2 max with 10 seconds rest between bouts, again this was done after a 10 minute warm-up. When more than 9 sets could be completed, the wattage was increased by 11 watts. If the subjects could not maintain a cadence of 85RPM, the workout was ended.
On the fifth day of training, they performed 30 minutes of exercise at 70% of VO2 max followed by 4 sets of the intermittent protocol and this session was designed to NOT be exhaustive. The anaerobic capacity test was performed at the beginning, week 2, week 4 and the end of the 6 week period; VO2 max was tested at the beginning and at week 3, 5 and the end of training.
Results
For group 1, the standard aerobic training group, while there was no increase in anaerobic capacity, VO2 max increased significantly from roughly 52 to 57 ml/kg/min (I say roughly because the paper failed to provide vaules, I’m going by what’s in the graphic below). Frankly, given the lack of anaerobic contribution to steady state training, the lack of improvement in this parameter is absolutely no surprise.
For group 2, both the anaerobic capacity and VO2 max showed improvements. VO2 max improved in the interval group from 48 ml/kg/min to roughly 55 ml/kg/min (see graphic below). It is worth noting that the interval group was starting with a lower value and may have had more room for improvement. Also note that they still ended up with a lower Vo2 max than the steady state group.
I’ve put Figure 2 from the paper (showing improvements in VO2 max) below
click this link to see the graph
http://www.bodyrecomposition.com/wp-...2009/07/vo2max
As I noted, pay attention to the fact that the Tabata group (black line, filled circles) started lower than the steady state group, they also still ended up lower than the steady state group. As well, note that pattern of improvement, the Tabata group got most of their improvement in the first 3 weeks and far less in the second three weeks. The steady state group showed more gradual improvement across the entire 6 week period but it was more consistent. As the researchers state regarding the Tabata group
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