Strength and muscle mass development after a resistance‑training period at terrestrial and normobaric intermittent hypoxia Benavente Bardera, Cristina Padial Puche, Paulino Scott, B. R. Almeida1¡, F. Olcina, G. Pérez‑Regalado, S. Feriche, B. Hypobaric hypoxia Biomarkers Performance This study investigated the effect of a resistance training ( RT) period at terrestrial (HH) and normobaric hypoxia (NH) on both muscle hypertrophy and maximal strength development with respect to the same training in normoxia (N). Thirtythree strength-trained males were assigned to N ( FiO2 = 20.9%), HH (2,320 m asl) or NH ( FiO2 = 15.9%). The participants completed an 8-week RT program (3 sessions/week) of a full body routine. Muscle thickness of the lower limb and 1RM in back squat were assessed before and after the training program. Blood markers of stress, inflammation (IL-6) and muscle growth (% active mTOR, myostatin and miRNA-206) were measured before and after the first and last session of the program. Findings revealed all groups improved 1RM, though this was most enhanced by RT in NH (p = 0.026). According to the moderate to large excess of the exercise-induced stress response (lactate and Ca2+) in HH and N, results only displayed increases in muscle thickness in these two conditions over NH (ES > 1.22). Compared with the rest of the environmental conditions, small to large increments in % active mTOR were only found in HH, and IL-6, myostatin and miR-206 in NH throughout the training period. In conclusion, the results do not support the expected additional benefit of RT under hypoxia compared to N on muscle growth, although it seems to favour gains in strength. The greater muscle growth achieved in HH over NH confirms the impact of the type of hypoxia on the outcomes. 2024-07-26T11:29:00Z 2024-07-26T11:29:00Z 2024-06-25 info:eu-repo/semantics/article Benavente, C. et. al. Pflugers Arch - Eur J Physiol 476, 1221–1233 (2024). [https://doi.org/10.1007/s00424-024-02978-1] https://hdl.handle.net/10481/93525 10.1007/s00424-024-02978-1 eng http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Atribución 4.0 Internacional Springer