June 20, 2012
Sex-based comparison of protein synthesis following resistance exercise.

The title says it all.  Who is better able to recover following resistance training?  The results may surprise you (or even motivate you).

Introduction:  Researchers sought out to see whether men or women have higher rates of protein synthesis during the early (1-5) and late (24-48) hour recovery periods.  In addition to the resistance training, they also gave a dose of whey protein (25g) that is expected to induce maximal muscle protein synthesis.  A secondary aim of this study was to see if the large amount of testosterone released by men post-exercise (10 to 15 times higher in men than women) would have an additive effect on muscle protein synthesis that women would not be able to obtain.

Methods:  Eight men and eight women who were participating in regular physical activity took part in this study.  The bout of exercise was an intense bout with 5 sets of 10 reps at 90% of a persons 10 rep maximum on the leg press as well as 3 sets of 12 reps of leg extensions/leg curls supersets.  Upon finishing this workout, subjects were given 25g of whey protein.

Results:  Starting rates of protein synthesis were similar between men and women.  After exercise, protein synthesis increased in men and women at 1-3 hours and remained elevated at 26-28 hours after with no difference between the sexes.Testosterone was approximately 45 times greater in men than women fifteen minutes after exercise but did not have an effect on muscle protein synthesis more than that of women.

Discussion/Conclusion:  This study shows that there are similar rates of muscle protein synthesis as well as anabolic cellular signaling events between men and women following resistance training plus a 25g dose of whey protein in the earl and late phases of post-exercise recovery.  Even though men had a far greater increase in testosterone than women post-exercise, it was not enough to increase protein synthesis more than women.  Therefore, the anabolic effect of resistance exercise clearly is working through some other mechanism other than spikes in testosterone levels.

My input:  So, men do not have it easier when it comes to weight training anabolic responses.  Both sexes are primed equally for muscle recovery.  The fact that they looked at testosterone comparisons really added to the quality of this study.  It is important to note that the authors are referring to muscle protein synthesis during a recovery phase and not muscle protein synthesis in a long-term muscle building sense.  However, recovery is the first step to adding muscle.

West et al J Appl Physiol. 2012 Jun;112(11):1805-13 

January 5, 2012
Here is a very interesting figure published in Diabetologia last month showing that across all age ranges, men (the black dots) develop Type 2 Diabetes at a lower BMI than women.  The means were 31.83 kg/m(2) (SD 5.13) in men and 33.69 kg/m(2) (SD 6.43) in women polled from 51,920 men and 43,137 women.  Now that’s a strong sample size.  It is very important to note that it is only Caucasians that were reported here and this may be different for other ethnic groups.
Diabetologia. 2011 Dec;54(12):3003-6.

Here is a very interesting figure published in Diabetologia last month showing that across all age ranges, men (the black dots) develop Type 2 Diabetes at a lower BMI than women.  The means were 31.83 kg/m(2) (SD 5.13) in men and 33.69 kg/m(2) (SD 6.43) in women polled from 51,920 men and 43,137 women.  Now that’s a strong sample size.  It is very important to note that it is only Caucasians that were reported here and this may be different for other ethnic groups.

Diabetologia. 2011 Dec;54(12):3003-6.