Born To Grow? Hereditary Influences on Muscular Adaptations

Authors

• Chris X. Parnell, Lehman College City University of New YorkFollow
• Adam E. Mohan, Lehman College City University of New YorkFollow
• Aidan Hopper, Lehman College City University of New YorkFollow
• Daniel Montenegro, Lehman College City University of New YorkFollow
• Alec Piñero, Lehman College City University of New YorkFollow
• Rune Segtnan, Lehman College City University of New YorkFollow
• Brad J. Schoenfeld, Lehman College City University of New YorkFollow

Abstract

GNYACSM Original Research Abstract

Born To Grow? Hereditary Influences on Muscular Adaptations

CHRIS X. PARNELL, ADAM E. MOHAN, AIDAN HOPPER, DANIEL MONTENEGRO, ALEC PINERO, RUNE SEGTNAN, BRAD J. SCHOENFELD

Applied Muscle Development Laboratory; Department of Exercise Science and Recreation; CUNY Lehman College; Bronx, NY

Category: Graduate

Advisor / Mentor: Schoenfeld, Brad J. (brad.schoenfeld@lehman.cuny.edu)

ABSTRACT

The individual variability in muscular adaptation to resistance training (RT) is a well-documented phenomenon, with genetic factors hypothesized to play a significant role. However, the extent to which heritable factors influence muscle hypertrophy remains equivocal due to the paucity of empirical evidence. PURPOSE: This study aimed to investigate the influence of heredity on muscular adaptations measured at baseline and after a standardized training protocol in untrained college-aged males with varying proportions of West African (WA) ancestry (n=19) or Central European (CE) ancestry (n=13). METHODS: In a prospective cohort-study design, 32 male subjects participated in an 8-week, supervised, standardized whole-body RT program occurring twice per week. Pre-post changes in fat-free mass (FFM) and regional muscle thickness (MT) of the upper and lower limbs were assessed by bioelectrical impedance analysis and ultrasound, respectively. Saliva-based DNA testing and hierarchical linear regression were then used to determine if genetic ancestry predicted muscle growth beyond baseline levels (p < 0.05) RESULTS: Following the 8-week protocol, FFM increased from 64.29 ± 8.74 kg to 65.08 ± 8.24 kg (mean change 0.82 kg; d = 0.10, WA 68.18 ± 8.840 kg; CE 59.52 ± 4.27 kg). Regionally, triceps MT increased from 38.43 ± 9.63 mm to 41.84 ± 9.27 mm (d = 0.36); however, no significant between-group difference was observed between groups when adjusted for baseline MT (𝒇2 = 0.097, p = .110). Conversely, lateral quadriceps 50% MT increased from 43.98 ± 7.00 mm to 46.50 ± 7.31 mm (d = 0.35). Between-group comparison indicated, CE ancestry was associated with greater hypertrophic gains compared to WA after adjusting for baseline MT (B = -0.022, 95% CI [-0.041, -0.004]; 𝒇2 = 0.22, p =.021). No corrections for multiple comparisons were performed and findings are considered exploratory. CONCLUSION: Results suggest a potential association between ancestry and regional, rather than systemic, muscular adaptations. However, due to the exploratory nature of this analysis and the small sample size, these findings are preliminary associations rather than causal mechanisms. Larger, more diverse cohorts are needed to clarify the influence of heritage on RT-induced hypertrophy.

Recommended Citation

Parnell, Chris X.; Mohan, Adam E.; Hopper, Aidan; Montenegro, Daniel; Piñero, Alec; Segtnan, Rune; and Schoenfeld, Brad J. (2026) "Born To Grow? Hereditary Influences on Muscular Adaptations," International Journal of Exercise Science: Conference Proceedings: Vol. 15: Iss. 8, Article 3.
Available at: https://digitalcommons.wku.edu/ijesab/vol15/iss8/3