Influence of Second Generation Oral Contraceptive Use on Adaptations to Resistance Training in Young Untrained Women

Abstract

Influence of second generation oral contraceptive use on adaptations to resistance training in young untrained women. J Strength Cond Res 36(7): 1801-1809, 2022-The study purpose was to determine effects of using second generation oral contraceptives (OC) on muscle adaptations to resistance training in young untrained women. Twenty users and 18 nonusers of OC completed a 10-week supervised progressive resistance training program. Before and after the intervention, muscle cross-sectional area (mCSA) of the quadriceps was measured using magnetic resonance imaging and muscle fiber CSA (fCSA) was determined by immunohistochemistry. In addition, body composition (DXA, fat mass/fat-free mass), maximal isometric muscle strength (dynamometry), 5 repetition maximum (5RM) leg press strength, counter movement jump (CMJ) height, and average power using a modified Wingate test were determined. Serum hormone analysis ensured OC compliance and 4-day food records documented dietary intake. After the training period, quadriceps mCSA (OC: 11.0 6 6.0% vs. non-OC: 9.2 6 5.0%, p 5 0.001), type II fCSA (OC: 19.9 6 7.9% vs. non-OC: 16.6 6 7.2%, p 5 0.05), muscle strength (knee extension, knee flexion and 5RM, p , 0.001), and functional power (CMJ, AP, p , 0.001) were significantly increased with no significant difference between the groups. However, a tendency toward a greater increase in fat-free mass (FFM) in the OC group was observed (OC: 3.7 6 3.8% vs. non-OC: 2.7 6 3.5%, p 5 0.08). Collectively, use of second generation OCs in young untrained women did not significantly improve adaptations to 10 weeks of resistance training compared with nonusers. The trend toward greater gains in FFM in the OC group warrant future studies.

Molecular markers of skeletal muscle hypertrophy following 10 wk of resistance training in oral contraceptive users and nonusers

“…A 2-year randomized, controlled trial in female runners indicated that OC assignment was associated with a significant gain in lean mass relative to controls (38), and resistance-trained women using OCs increased lean mass significantly after eight weeks of resistance training whereas non-users did not (39). Furthermore, previous data from our lab demonstrated a greater response to resistance training in untrained 3 rd generation OC users compared to non-users following 10 weeks of resistance training (9), while the effect in 2 nd generation OC users were less pronounced, although trends towards greater gains in lean mass were reported (10). In addition, a recent study by Wallner et al showed a positive effect of providing EE and the progestin Dienogest in physiologic concentrations on human skeletal muscle cell proliferation and myogenic potential in vitro, supporting the notions of an anabolic effect of OCs (49).…”

“…This article presents data from a prospective cohort study that was designed primarily to assess the effect of 10-weeks resistance training on gain of muscle mass in 2 nd generation OC users and nonusers (10). Here, we assess the myogenic response to resistance training from muscle biopsies obtained from the study by Dalgaard et al 2020 (10). The study was carried out in accordance with the Declaration of Helsinki, approved by the Central Denmark Region Committees on Health Research Ethics (Journal no.…”

“…A detailed description of the study protocol has been reported previously (10). Shortly, a prospective cohort study was conducted where users (n=20) and non-users (n=19) of 2 nd generation OCs completed a 10-week supervised progressive resistance training intervention.…”

“…Subjects were recruited through posters distributed on the local university and through social media. All participants, who met the inclusion criteria (10) were invited to an introduction meeting, which included information on risks and benefits related to participation in the study, completion of a physical activity questionnaire, measurement of anthropometry, and a familiarization session to the laboratory tests. A detailed description of inclusion and exclusion criteria has been reported previously (10).…”

“…Thus, it is not known whether EE alone or combined with progestins (as in OCs) influences the regulatory proteins differently than the endogenous female hormones. However, these molecular pathways are promising candidates to explain the differences in the anabolic response observed between OC-users and non-users (9,10). A body of evidence from rodents demonstrates that administration of estrogen manipulates the proteolytic system and antiinflammatory response, thus enhancing recovery from muscle damage (27,28,45,47).…”