Does Strength Training Boost Your Metabolism?

I've seen exaggerated claims pro and con about themuscle, leading to a significant increase in resting
question of strength training and metabolism. Somemetabolic rate (RMR).
authors imply that if you pump iron for a week orThis was stated by the authors of the Campbell
two you'll be able to pound down an extra Big Macstudy, who never made the 50 calorie per pound per
and quart of ice cream per day.day claim: "The increase in RMR is due to an increase
The most pessimistic authors declare that there isin the metabolic activity of lean tissue and not an
almost no increase in metabolism from strengthincrease in the amount of lean tissue mass".
training. In the middle the statement that gaining an[Campbell, 1994]. Various factors may cause this
extra pound of muscle boosts metabolism by aboutincrease, including repair of tissue damage, increased
50 calories per day is often made. So who's right?protein synthesis, etc. Using the 6 calorie per pound
The 50 calorie per day notion comes from looking atper day result as justification that there is very little
studies like that by Campbell, et al [Campbell, 1994],increase in metabolism is also a misinterpretation,
which showed about a 7% increase in metabolimsagain based on the wrong assumption that it's the
among participants in a 12 week resistance trainingextra pounds of muscle that matter.
program.So strength training will increase your metabolism, by
This amounts to around 150 calories per day, and themaking all your muscles a bit more active. This
participants gained on average about 3 pounds ofrevving up lasts at least a couple of days after
muscle, so it appears that each pound of muscletraining- the 7% boost mentioned above was
boosted metabolism by 50 calories per day. Similarmeasured 45 hours after the participants' last training
results have been found in other studies, e.g. [Pratley,session.
1995].Personally its not my main reason for doing it, I'm
On the other hand, the calorie consumption of muscleafter things like bone health and fighting off
has been directly measured and found to be about 6age-related decline in muscle. But I don't mind any
calories per pound per day[McClave, 2001]. Further,help my metabolically challenged old body can get.
each pound of fat burns up 2 calories per day, so ifReferences
you lose a pound of fat and gain a pound of muscle-Campbell, W, Crim, M, Young, V, and Evans, W.
there should only be a net boost in your metabolism"Increased Energy Requirements and Changes in
of 4 calories per day, as one author put it, maybeBody Composition With Resistance Training in Older
enough for a celery stick.Adults", American Journal of Clinical Nutrition,60: 167,
Based on this result, science writer Gina Kolata in her1994.
book claimed that strength training does not boost-Kolata, G, Ultimate Fitness: The Quest for Truth
metabolism Ultimate Fitness [Kolata, 2003], and similarabout Health and Exercise, Farrar Straus Giroux, 2003.
reasoning was used in an article in Runner's World by-McClave, Stephen A.; Snider, Harvy L., "Dissecting
well-known running writer Amby Burfoot.The Energy Needs Of The Body", Current Opinion In
The two results, both from careful scientific studies,Clinical Nutrition And Metabolic Care, 4(2):143-147,
seem to present a paradox. But it turns out the 502001.
calorie per day argument is a misinterpretation of the-Pratley R, et al, "Strength Training Increases Resting
Campbell results. It's not that 3 extra pounds ofMetabolic Rate And Norepinephrine Levels In Healthy
muscle boosted the participants metabolism 7%,50- To 65-yr-old Men", J. Appl Physiol., 79(3):818-23,
instead the strength training revved up all their1995.