How fast can you start putting on muscle?


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The traditional view is that it takes at least 6-8 weeks of hard resistance training before your muscles start getting bigger. You’ll see strengths gains long before that, the theory goes, but they come from neural factors (basically the “contract” signal from your brain gets the message to your muscle fibres more effectively). In the last few years, though, that orthodoxy has been challenged by a few studies that claimed to see muscle increases after just a few weeks of training. A new study from the University of Oklahoma, published in the European Journal of Applied Physiology, should help settle the debate. They set out to do a study with three key characteristics:

  1. Hard training: the subjects trained three times a week for eight weeks. The program was leg press, leg extension and bench press. Each exercise was three sets to failure with two minutes rest, with the weight chosen so that failure occurred after 8 to 12 reps in each set.
  2. Frequent testing: instead of just doing before-and-after measurements, the testers measured strength and muscle cross-sectional area every week for eight weeks.
  3. Sensitive measurement: a tape measure won’t cut it. They used a CT scanner to measure the muscle cross-sectional area at the midpoint of the thigh.

Here’s what they found:

The top line is muscle size, bottom is strength. The first two data points are the pre-training baseline measurements. It’s possible that the initial jump in muscle size after the first week (i.e. after just two training sessions) is predominantly due to swelling associated with muscle soreness. But the soreness had totally dissipated by week 3, so by then we’re unquestionably dealing with actual hypertrophy. By the end of the eight weeks, the total increase in muscle size (CSA) was 9.6%. Two comments. First, I was curious as to why they included bench press when all the measurements are on the legs. In discussing why an earlier study failed to see gains quite this early, the researchers note that

subjects only performed one exercise (leg extensions), so the training stimulus was not as great as that in the present study.

Does this mean that upper-body training can contribute to lower-body hypertrophy, perhaps by tweaking anabolic hormone levels and ramping up whole-body protein synthesis? I’m not sure — if anyone can clarify, please do so in the comments section. Second, this training program is hard. Three times a week, three sets of three exercises may not sound that tough — but every set is to failure (much like the controversial low-weight approach advocated by Stu Phillips, actually). If you really want to put on muscle quickly, you have to work hard.

7 Replies to “How fast can you start putting on muscle?”

  1. If CT scanner time was inexpensive, you’d want to have one intervention per study. However, putting 25 people in a CT scanner eight times is probably not inexpensive and perhaps they sort of hedged their bets by studying an upper and a lower body intervention. That way you can have two, perhaps three articles out of one data set. Makes sense from the viewpoint of the traditional theory too. If there is a delay in onset of muscle growth, you’d want to know if this is the same for different parts of the body.

    If this is so, the remark about previous studies having only one leg exercise refers to the subjects in this study having to perform two leg exercises.

  2. @Felice: Thanks for that link — it’s exactly what I was wondering about. (For those who haven’t clicked: the study compared training JUST an arm muscle with training the same arm muscle along with strenuous leg weights that prompted significant increases in growth hormone, IGF-1, and testosterone. There was NO difference in arm strength or hypertrophy between the two groups.)

    I should clarify that in the study that I blogged about above, they only tested leg strength and hypertrophy. The subjects performed bench press, but unless I’m missing something there was no outcome or measurement related to the upper body.

    Which brings me to @RH’s comment: that’s certainly a reasonable hypothesis! We’ll have to see whether another study from the same group emerges in the next few months… However, as I re-read the paper, I suspect that may not be the case, as the scanning was done with a “peripheral quantitative computed tomography” scanner, and “the scan was taken at the midpoint of the thigh.” I’m not a CT expert, but it sounds to me like the subjects didn’t get full-body scans. (Though there may well be a completely different set of upper-body measurements that wasn’t even mentioned in this paper.)

    It’s worth noting that the West et al. paper than Felice linked to was only published in the Jan. 2010 issue of JAP, while this study was submitted in August 2010. That suggests that whether whole-body elevation of anabolic hormones affects local hypertrophy was considered an “open question” during the design and data collection of the study.

  3. Different theory: Perhaps they figured that an eight week hardcore training progamme that sends you away wit bulky legs and a chicken chest just isn’t going to attract volunteers.

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