Sunday, September 20, 2009

Interval training vs. Long slow: part 1

The traditional exercise theory for fatburning has been to get on a cardio machine and go for 30-60+ minutes at a slow pace. This is our "optimal" fat burning zone, so they say.

Also, for endurance training (marathon, 5k, etc) the theory has been to be able to run long distances you have to run long distances. (yes I said it)

There is new research proclaiming that interval training (shorter bouts of high intensity exercise with bouts of rest) burns more fat and produces the same cardiovascular/ endurance changes, if not slightly more than long slow training.

Here are some articles and a brief summary of what they found:


Wallman K, Plant LA, Rakimov B, Maiorana AJ. The effects of two modes of exercise on aerobic fitness and fat mass in an overweight population. Res Sports Med. 2009;17(3):156-70

Two groups were selected (either interval training and diet education (INT group), continuous aerobic exercise and diet education (CON group), or diet education only (DIET group)) and were found to have similar significant improvements in VO2 max and time to exhaustion on a graded exercise test. Only the INT group was found to have a large effect size for loss in android (belly) fat mass over time.


M J Gibala, J Little, M van Essen, GWilkin, K Burgomaster, A Safdar, S Raha and M Tarnopolsky Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance September 15, 2006 The Journal of Physiology, 575, 901-911.

Brief, intense exercise training may induce metabolic and performance adaptations comparable to traditional endurance training. Training decreased the time required to complete a bicycling test equally between both groups. Biopsy samples obtained before and after training revealed similar increases in muscle oxidative capacity, as reflected by the maximal activity of cytochrome c oxidase (COX) and COX subunits II and IV protein content (main effects, P ≤ 0.05), but COX II and IV mRNAs were unchanged. Training-induced increases in muscle buffering capacity and glycogen content were also similar between groups (main effects, P ≤ 0.05). Given the large difference in training volume, these data demonstrate that SIT is a time-efficient strategy to induce rapid adaptations in skeletal muscle and exercise performance that are comparable to ET in young active men.

Tremblay, Angelo, et al. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. Vol 43. no 7 (July). Pp 814-818. 1994

Researchers at Laval University in Quebec divided participants into two groups: long duration
and repeated short-duration exercisers.1 They had the long-duration group cycle 45 minutes
without interruption. The short-term interval group cycled in numerous short bursts of 15-90
seconds, while resting in between.
The long duration group burned twice as many calories, so you would assume they would burn
more fat. However, when the researchers recorded their body composition measurements, the
interval group showed that they lost the most fat.
In fact, the interval group lost 9 times more fat than the endurance group for every calorie
burned.


D. C. Poole and G. A. Gaesser, Response of ventilatory and lactate thresholds to continuous and interval training, Journal of Applied Physiology, Vol 58, Issue 4 1115-1121
We conclude that both continuous and interval training were equally effective in augmenting LT (lactate threshold), but interval training was more effective in elevating VT (Ventilatory threshold).

Talanian JL, Galloway SD, Heigenhauser GJ, Bonen A, Spriet LL. Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women. J Appl Physiol 102: 1439–1447, 2007.

In summary, seven sessions of HIIT over 2 wk induced marked increases in whole body and
skeletal muscle capacity for fatty acid oxidation during exercise in moderately active women. Exercise whole body fat oxidation increased by 36% (from 15.0 _ 2.4 to 20.4 _ 2.5 g) after HIIT. Resting muscle glycogen and triacylglycerol contents were unaffected by HIIT, but net glycogen use was reduced during the posttraining 60-min cycling trial. HIIT offers a mechanism to quickly increase muscle mitochondrial capacity, as well as whole body fat oxidation and V˙ O2 peak, in untrained individuals.

Tjønna, AE., Et al (2008). Aerobic interval training (AIT) versus continuous moderate exercise (CME). Circulation, 118, 346-354.

“Of all established risk factors, low aerobic exercise capacity appears to be the strongest predictor of mortality.5 We demonstrated here that high-intensity exercise (AIT) increased V˙O2max to a higher degree than moderate-intensity exercise (CME) in patients with the metabolic syndrome.“

“Physical activity and a healthy lifestyle promote insulin sensitivity, whereas a sedentary lifestyle and a Western diet are associated with insulin resistance. In our study, AIT promoted insulin sensitivity and cell function more than CME”

”The present study demonstrates that high-intensity exercise training is superior to moderate-intensity training in reversing risk factors of the metabolic syndrome.”

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Pretty interesting huh? To think that interval training for fewer minutes per week (at higher intensities) would provide so many benefits compared to long slow training. Americans have a "more is better" mentality these days, so it's hard for some people to get out of that thinking.

For further (anecdotal) proof let's take a look at a sprinter and an endurance athlete, like a marathon runner. Which person has the more appealing physique (more muscle mass and less body fat)? The sprinter of course. Why don't we train like that then? High intensity training is hard and people don't want to work hard. It's easier to go slow for 60 minutes rather than hard for 20. That's 40 minutes of your life you just waisted.

Photobucket

Next time I will post some different exercise protocols for interval training.

3 comments:

Unknown said...

Check out http://www.pponline.co.uk/encyc/training-plan-monitoring-your-training-intensity-40879

In long-term studys continous training at slower paces is more effective than the interval approach from a performance standpoint. It is hard to find long-term studies though, as most univeristy studies are engineered around 6 to 12 week due to students semester schedules.

steve said...

I love how you used a drugged up sprinter for the pic.

It's a a balance issue. Neither is superior to the other. Both need to be done. They provide different stimulus and adaptation. Even when they provide the same adaptation, i.e. increased mitochondria or aerobic capacity, they do so via different signalling pathways.

In terms of pure performance, the research shows that for interval/intense training to be the most beneficial it needs to be preceded by or combined with endurance work.

To what degree depends on what you are training for, but it's why even most of the elite sprinters will do 2-3mi jogs or extensive interval training during their offseason.

mikedickey123 said...

Steve, touche about the pic, but let's put in any anaerobic athlete and compare it to the typical endurance athlete and then compare body types.
What I was trying to disseminate here was that in this research, they clearly state that you can, at minimum, get similar results in health benefits when doing interval training or long slow training. The difference is the time you have to put in. Why would you workout or run for 2 hours when you can get it done in less time with less stress on your musculoskeletal system. Of course you would have to run/ bike distance, but not the 18+ miles in a normal end state marathon program. I ran my first marathon in just under 4 hours, not running in training more than 13.1 miles.

I'd be interested to see the research you were quoting if you have the links. thanks for the discussion