The aim of this study was to compare the effect of self-selected repetition duration (SELF), with and without volume load (VL) equalized with controlled repetition duration (CON) on muscle strength and hypertrophy in untrained males. We used a within-subjects design in which 20 volunteers (age: 24.7 ± 2.9 years) had one leg randomly assigned to CON (i.e., 2 s concentric, 2 s eccentric) and the other to SELF or to self-selected repetition duration with equalized volume load (SELF-EV). One repetition maximum (1-RM) and muscle cross-sectional area (CSA) were measured at baseline (Pre) and after (Post) resistance training (RT; 2Â/wk for 8 weeks). For the main study variables (1-RM and muscle CSA), a mixed-model analysis was performed, assuming repetition duration (SELF, SELF-EV and CON), and time (Pre and Post) as fixed factors and the subjects as random factor for each dependent variable (1-RM and CSA). All RT protocols showed significant increases in values of 1-RM from Pre (CON: 73.7 ± 17.6 kg; SELF: 75.9 ± 17.7 kg; and SELF-EV: 72.6 ± 16.9 kg) to Post (CON: 83.4 ± 19.9 kg, effect size (ES): 0.47; SELF: 84 ± 19.1 kg, ES: 0.43; and SELF-EV: 83.2 ± 19.9 kg, ES: 0.57, P < 0.0001). Muscle CSA values increased for all protocols from Pre (CON: 12.09 ± 3.14 cm 2 ; SELF: 11.91 ± 3.71 cm 2 ; and SELF-EV: 11.93 ± 2.32 cm 2 ) to Post (CON: 13.03 ± 3.25 cm 2 , ES: 0.29; SELF: 13.2 ± 4.16 cm 2 , ES: 0.32; and SELF-EV: 13.2 ± 2.35 cm 2 , ES: 0.53, P < 0.0001). No significant differences between protocols were found for both 1-RM and CSA (P > 0.05). Performing RT with SELF, regardless of VL, was equally effective in inducing increases in muscle strength and hypertrophy compared to CON in untrained men. Subjects Anatomy and Physiology, KinesiologyHow to cite this article Chaves TS, Pires de Campos Biazon TM, Marcelino Eder dos Santos L, Libardi CA. 2020. Effects of resistance training with controlled versus self-selected repetition duration on muscle mass and strength in untrained men. PeerJ 8:e8697 Schoenfeld BJ, Ogborn DI, Krieger JW. 2015. Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis. Sports Medicine 45(4):577-585 DOI 10.1007/s40279-015-0304-0.Schoenfeld BJ, Ogborn D, Krieger JW. 2017. Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis.

N óbrega, SR, Scarpelli, MC, Barcelos, C, Chaves, TS, and Libardi, CA. Muscle hypertrophy is affected by volume load progression models. J Strength Cond Res 37(1): 62-67, 2023-This exploratory secondary data analysis compared the effects of a percentage of 1 repetition maximum (%1RM) and a repetition zone (RM Zone) progression model carried out to muscle failure on volume load progression (VL Pro ), muscle strength, and cross-sectional area (CSA). The sample comprised 24 untrained men separated in 2 groups: %1RM (n 5 14) and RM Zone (n 5 10). Muscle CSA and muscle strength (1RM) were assessed before and after 24 training sessions, and an analysis of covariance was used. Volume load progression and accumulated VL (VL Accu ) were compared between groups. The relationships between VL Prog , VL Accu , 1RM, and CSA increases were also investigated. A significance level of p # 0.05 was adopted for all statistical procedures. Volume load progression was greater for RM Zone compared with %1RM (2.30 6 0.58% per session vs. 1.01 6 0.55% per session; p , 0.05). Significant relationships were found between 1RM and VL Prog (p , 0.05) and CSA and VL Prog (p , 0.05). No between-group differences were found for VL Accu (p . 0.05). Analysis of covariance revealed no between-group differences for 1RM absolute (p , 0.05) or relative changes (p , 0.05). However, post hoc testing revealed greater absolute and relative changes in CSA for the RM Zone group compared with the %1RM group (p , 0.001). In conclusion, RM Zone resulted in a greater VL Pro rate and muscle CSA gains compared with %1RM, with no differences in VL Accu and muscle strength gains between progression models.

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We conducted a systematic review to synthesize evidence of the effect of nature-based adventure (NBA) interventions on depressive symptoms. Our search was conducted in April 2021 and utilized the following databases: MEDLINE (PubMed), PsycINFO, SPORTDiscus, CINAHL, Google Scholar, and Clinicaltrials.gov. Forty-two studies ( n = 2,689 participants) with different designs, published between 1979 and 2021, were included. Collectively, results suggest highly variable effects of NBA interventions on depressive symptoms, ranging from reductions in mean depression scores of up to 64% to increases in means scores of up to 18%. Patient adherence to interventions was also variable, and serious adverse events (e.g., leg fractures) did occur. Despite variability across studies, research generally showed that mountain-based and surfing interventions, coupled with other forms of care, may substantially reduce adults’ depressive symptoms more than usual care alone or no intervention, highlighting the potential benefits of some NBA activities for individuals experiencing depressive symptoms.