Another interesting study has been reported at the American Physiological Society meeting held in New Orleans. A team of researchers has now examined the effects of oral contraceptives on female muscle mass, and found that oral contraceptive use impairs muscle gains in young women, and is associated with lower hormone levels. Many active young women use oral contraceptives (OC) yet this is the first time its effect on their body composition and exercise performance has been studied.
Dr. Chang-Woock Lee and Steven E. Riechman of Texas A&M University did this work, along with Mark A. Newman at the University of Pittsburgh. They studied seventy-three generally healthy women between the ages of 18-31 who completed a 10-week whole-body resistance exercise training program in two groups. Group 1 consisted of 34 women who used oral contraceptives (OC). Group 2 consisted of 39 women who did not take birth control pills (non-OC). The women were encouraged to consume at least 0.5 grams of protein per pound of body weight per day (a third more than is called for by the U.S. government nutritional guidelines) to make sure they consumed enough calories and protein to promote muscle growth.
The young women were on a very aggressive muscle-building campaign; participants exercised three times per week for ten weeks under the supervision of exercise physiologists. They performed a variety of exercises to include chest press, lat pull down, leg extension, triceps extension, arm curl and abdominal crunch. Exercise was done using standard exercise machines and each volunteer performed three sets of 6-10 repetitions per exercise at 75 percent of their maximum strength. Body composition was determined using hydrostatic weighing.
At the conclusion, researchers found that there were significant differences in lean mass gains. However, other muscle responses such as strength gains and arm/leg circumferences were similar between the OC and non-OC users. Resting/fasting blood concentrations of the anabolic hormones were significantly lower in women taking OC vs. non-OC users throughout the study period. At the same time, plasma concentrations of cortisol (catabolic hormone) were elevated. In addition, those OC users had reduced DHEA hormone at the end of the training period. By contrast, the other participants’ levels did not change.
According to the researchers, “We were surprised at the magnitude of differences in muscle gains between the two groups, with the non-OC women gaining more than 60% greater muscle mass than their OC counterpart.”
Dave
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4 comments:
I had a post from an anonymous poster Stabbysox who put a link in the post, and because of the commercial nature of most links I won't post them.
Sorry Stabbysox. In answer to your question, I didn't feel that the numbers you mention were critical to the article, and because they confused me (and would confuse most readers), I left that part of their press release out of my blog. I don't believe it affects the article; perhaps it even has a positive effect on the "readability" of the piece,
Dave
that article shows the error of the reported research overlaps lots from group to group? do realistic stats truly make the results significant (and thusly, the research sham vs wham)? or was the linked article itself wrong?
in this way i was curious about your interpretation of the news.
Hi Stabby,
I just wrote the publisher and asked for a detailed copy of the research. If we get it, I'll publish a link.
Dave
Just spoke to them . . . They are at their annual meeting in New Orleans where this work is being presented. They will "get back to me" when the meeting concludes. Let's hope this happens,
Dave
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