Affective and Perceptual Responses During an 8-Week Resistance Training to Failure Intervention at Low vs. High Loads in Untrained Women.

ABSTRACT: Anderson, AlOK, Voskuil, CC, Byrd, MT, Garver, MJ, Rickard, AJ, Miller, WM, Bergstrom, HC, and Dinyer McNeely, TK. Affective and perceptual responses during an 8-week resistance training to failure intervention at low vs. high loads in untrained women. J Strength Cond Res 37(3): 546-554, 2023-This study examined the effects of resistance training (RT) to failure on the perceptual and affective responses, intent-to-continue RT to failure in a self-initiated session, and affect-intent relationship. Twenty-three untrained women (mean ± SD : age 21.2 ± 2.2 years; height 167 ± 5.7 cm; body mass, 62.3 ± 16.2 kg) completed an 8-week, full-body RT to failure intervention at a low (30% 1RM; n = 11) or high (80% 1RM; n = 12) load. The Borg's rating of perceived exertion (RPE) scale was used to assess the acute (aRPE) and session (sRPE) RPE immediately after repetition failure and each training session, respectively. Immediately, 15-minute, and 60-minute postsession affective responses were assessed using the feeling scale (FS; -5 to +5), and intent to continue to RT was assessed on a scale of 0-100% intention. During week 4 (W4) and week 8 (W8), aRPE (W4: 18 ± 2, W8: 18 ± 2; p ≤ 0.032) and sRPE (W4: 17 ± 2, W8: 18 ± 1; p ≤ 0.018) were greater than that during week 1 (W1; aRPE: 17 ± 2; sRPE: 16 ± 2). The FS responses increased from immediately to 60-minute postsession during W4 ( p ≤ 0.019) and W8 ( p ≤ 0.049). The correlation between affect and intent-to-continue RT increased from W1 ( r = 0.416) to W8 ( r = 0.777). Regardless of load, untrained women reported similar perceptual, affective, and intention responses. These variables should be considered to improve RT program adoption and adherence in women.

Effects of Nitrate Supplementation on Muscle Strength and Mass: A Systematic Review.

ABSTRACT: Anderson, OK, Martinez-Ferran, M, Lorenzo-Calvo, J, Jiménez, SL, and Pareja-Galeano, H. Effects of nitrate supplementation on muscle strength and mass: a systematic review. J Strength Cond Res 36(12): 3562-3570, 2022-This systematic review examines the effect of dietary nitrate supplementation (SUP) on muscle strength and hypertrophy when combined with physical exercise. The databases PubMed, Web of Science, and MEDLINE were searched for full-text articles published between January 2000 and June 2020. For inclusion, studies had to report on the effects of SUP administered as acute or chronic doses together with a standardized exercise protocol on muscle strength and hypertrophy compared with placebo in healthy adults who were sedentary, physically active, or professional athletes. Twelve studies (1,571 subjects) were finally selected. In 5 studies, the SUP regime was acute, and in 7, it was chronic. SUP was nitrate-rich beetroot juice in 9 studies, a potassium nitrate capsule in 1, and increased dietary nitrate in 2. Ingested nitrate was 64-1,200 mg. Of the 12 studies, 6 observed an ergogenic effect of SUP compared with placebo. These findings indicate that muscle strength gains are possible provided the dose, format, frequency, period, and exercise test are appropriate. Best results were observed with a minimum acute dose of 400 mg of nitrate provided as beetroot juice/shot taken 2-2.5 hours before exercise involving low- and high-intensity muscle contractions. This SUP regime seems to improve muscle efficiency in terms of reduced phosphocreatine and energy costs (P-magnetic resonance spectroscopy) and improved time to exhaustion.