Thursday, January 8, 2009

Switch to intervals to maintain your fitness with less training?

Well that is the implication of this study as I read it.

The researchers took some endurance athletes and replaced their regular endurance style training with "frequent high-intensity sessions each consisting of 8–12 30-s sprint runs separated by 3 min of rest".

There was a big reduction in training volume but these guys maintained their fitness and actually got more efficient at using energy....

Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume

We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training (45 km/wk) with frequent high-intensity sessions each consisting of 8–12 30-s sprint runs separated by 3 min of rest (5.7 ± 0.1 km/wk) with additional 9.9 ± 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower (P < 0.05) at running speeds of 11, 13, 14.5, and 16 km/h, respectively, in SET, whereas remained the same in Con. No changes in blood lactate during submaximal running were observed. After the IT period, the protein expression of skeletal muscle UCP3 tended to be higher in SET (34 ± 6 vs. 47 ± 7 arbitrary units; P = 0.06). Activity of muscle citrate synthase and 3-hydroxyacyl-CoA dehydrogenase, as well as maximal oxygen uptake and 10-km performance time, remained unaltered in both groups. In SET, the capillary-to-fiber ratio was the same before and after the IT period. The present study showed that speed endurance training reduces energy expenditure during submaximal exercise, which is not mediated by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training.


Anonymous said...

Watch out:

By the way, great blog.


Chris said...



Mark Twight's perspective is not one I'd argue with - he knows his stuff and has really been there.

I've referred to his changed view on these things before - 15 July 08 and 2 May 08.

This is still interesting research

Anonymous said...

I'd love to know whether the measured quantities actually translate into sustained and/or improved performance. A 30 minute run for distance both pre- and post- study would have been helpful.

I have been helping a buddy train for marathons, and bought into the intense interval/lower distance method of training that Mark Twight criticizes in the article cited by Alex. My friend really battled fatigue toward the end of his races and seemed to plateau rather quickly, and hasn't reached his goal of qualifying for Boston, despite being able to run some decent 5 and 10k times (sub 19 and sub 40, respectively).

We have transitioned to a more volume-oriented approach w/ a few intervals thrown in for the next marathon. It will be interesting to see the results.

Thanks for the great blog!

Chris said...

Thanks Ben. A 19 min 5K is pretty impressive!

Whiel I think that intervals can really boost VO2 etc and improve fitness I do think that if you are goign to run long you do need to train long too - at least occasionally. Even for things like being on your feet for 2 or 3 hours

Rob at Mountain Athlete has has posted some similar ideas - learning a lot from Twight.

Crossfit Endurance seem to be training peole for marathons and ultras on high intensity intervals but as I said I thibnk that at least occaisionally a marathoner will need some long runs.

Whether marathons and long runs are actually healthy is another issue ;-)

Anonymous said...

Most, if not all, studies on intervals are of short duration, no more than 6 weeks, I believe. There probably is a reason for that: performance improvement propbably stops at this stage and you have to go back to more traditional training to keep improving your endurance.

Anonymous said...

I like intervals, but let's not forget that the participants from this study were already well trained endurance athletes. It is as if they climbed to the top of a mountain and are now trying something new. Those who are at the bottom of the mountain can't expect to do the same.

Endurance training gets wrongly knocked by many today and that is unfortunate.


Chris said...

Incidentally I did a 5K race yesterday. Not in a great time but I ran the whole thing which was my aim and the conditions were rough - massive hill and strong winds.

Anyway, I suppose my point is that I don't ever run anything near 5K. I walk lots, do some sprints, circuits etc. If was was to do more long runs I am sure I'd have run faster, but I was happy with what I did.


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