Just read a few studies elsewhere, but I found this one most significant as it had a decent sample size.
Oral Contraceptive Use Impairs Muscle Gains in Young Women
Chang Woock Lee1, Mark A. Newman2 and Steven E. Riechman1,3
1 Health and Kinesiology, Texas A&M University, College Station, TX
2 Human Energy Research Laboratory, University of Pittsburgh, Pittsburgh, PA
3 Nutrition, Texas A&M University, College Station, TX
ABSTRACT
Background: Many active young women use oral contraceptive (OC) yet its effect on their body composition and exercise performance has not been thoroughly studied. We examined the effects of oral contraceptive on muscle responses to resistance exercise training (RET).
Methods: 2 groups of 18-31 year old subjects (OC: n=34, no OC: n= 39) underwent 10 week whole-body RET (3x/week, 3 sets, 6-10 reps, at 75% of max strength). Body composition was determined using hydrostatic weighing. Blood samples were taken before/after the training and assayed for DHEA, DHEAS, cortisol, and IGF1.
Results: There were significant differences in lean mass gains (OC: 2.1±2.1%, no OC: 3.5±3.2% / OC: 1.0±1.0kg, no OC: 1.6±1.4kg, p<0.05). Plasma concentrations of DHEA, DHEAS, and IGF1 were significantly lower and cortisol was elevated in OC (DHEA: OC 9.5±4.4, no OC 13.6±4.6 / DHEAS: OC 1451±685, no OC 2196±1008 / IGF1: OC 163±42, no OC 239±126 / cortisol: OC 33.4±10.8, no OC 24.3±9.4, ng/ml, p<0.05). There also were significant differences in lean mass gains depending on androgenicity of the progestin in OC (low=2.5%, medium/high=0.3%, P<0.05).
Conclusion: Oral contraceptive use impaired muscle gains in young women which was associated with lower DHEA, DHEAS and IGF1 and higher cortisol. The diminished lean mass gain may be related to the androgenicity of progestin which may bind to androgen receptor and inhibit its function.
Notice the authors do not even tell us which brands of BC had the most androgenic form of progestin, so we don't even know which one to avoid the most. Thanks.
Oral Contraceptive Use Impairs Muscle Gains in Young Women
Chang Woock Lee1, Mark A. Newman2 and Steven E. Riechman1,3
1 Health and Kinesiology, Texas A&M University, College Station, TX
2 Human Energy Research Laboratory, University of Pittsburgh, Pittsburgh, PA
3 Nutrition, Texas A&M University, College Station, TX
ABSTRACT
Background: Many active young women use oral contraceptive (OC) yet its effect on their body composition and exercise performance has not been thoroughly studied. We examined the effects of oral contraceptive on muscle responses to resistance exercise training (RET).
Methods: 2 groups of 18-31 year old subjects (OC: n=34, no OC: n= 39) underwent 10 week whole-body RET (3x/week, 3 sets, 6-10 reps, at 75% of max strength). Body composition was determined using hydrostatic weighing. Blood samples were taken before/after the training and assayed for DHEA, DHEAS, cortisol, and IGF1.
Results: There were significant differences in lean mass gains (OC: 2.1±2.1%, no OC: 3.5±3.2% / OC: 1.0±1.0kg, no OC: 1.6±1.4kg, p<0.05). Plasma concentrations of DHEA, DHEAS, and IGF1 were significantly lower and cortisol was elevated in OC (DHEA: OC 9.5±4.4, no OC 13.6±4.6 / DHEAS: OC 1451±685, no OC 2196±1008 / IGF1: OC 163±42, no OC 239±126 / cortisol: OC 33.4±10.8, no OC 24.3±9.4, ng/ml, p<0.05). There also were significant differences in lean mass gains depending on androgenicity of the progestin in OC (low=2.5%, medium/high=0.3%, P<0.05).
Conclusion: Oral contraceptive use impaired muscle gains in young women which was associated with lower DHEA, DHEAS and IGF1 and higher cortisol. The diminished lean mass gain may be related to the androgenicity of progestin which may bind to androgen receptor and inhibit its function.
Notice the authors do not even tell us which brands of BC had the most androgenic form of progestin, so we don't even know which one to avoid the most. Thanks.