Xu Junhai, Farney Tyler M, Nelson Arnold G
School of Kinesiology, Louisiana State University, Baton Rouge, LA, USA.
Department of Health & Kinesiology, Texas A&M University-Kingsville, Kingsville, TX, USA.
Int J Exerc Sci. 2020 May 1;13(2):744-754. doi: 10.70252/WHOM9599. eCollection 2020.
Supplements are widely used in recreational and professional participants; however, their claimed benefits are hardly to test. This study compared the total lifted numbers and post-exercise estimated MVO while subjects were treated with either Muscle Sentry (MS) or placebo (PL), in a 7-day washout period. Participants (11 women, 10 men, 20-24 years) performed 3 sets to failure chest and leg press exercises at 8 RM with 2 min rest between sets. Each exercise was performed four times (2 × MS, 2 × PL) at the same time of the day separated by 48 h. The supplementation was ingested 40 min prior to perform the exercise. Prior to the exercise and immediately after each set, both HR and BP were obtained. The rate pressure product (RPP) was then calculated to determine estimated MVO. Daily RPP and total weight lifted (chest + leg) for each supplementation were averaged. Normalized RPP was the ratio of averaged RPP and averaged total weight lifted. No treatment effect on chest, leg and total lift numbers, normalized post RPP (NPRPP), normalized RPP (NRPP) (p=0.94, 0.86, 0.87, 0.87, 0.43 respectively); No treatment effect on total lift numbers, NPRPP, NRPP for gender (p=0.87, 0.95, 0.96 respectively). Ingestion of Muscle Sentry 40 min prior to do 3 sets to failure of both chest and leg presses had no effect upon either total lift numbers or estimated MVO. This suggests that, in some instances, the benefits of Muscle Sentry are less than those claimed by the manufacturer.
补充剂在休闲和专业运动参与者中广泛使用;然而,其宣称的益处很难得到验证。本研究比较了受试者在接受肌肉哨兵(MS)或安慰剂(PL)治疗、为期7天的洗脱期内的总举重次数和运动后估计的最大摄氧量(MVO)。参与者(11名女性、10名男性,年龄20 - 24岁)以8RM的重量进行3组直至力竭的胸部和腿部推举练习,组间休息2分钟。每项练习在一天中的同一时间进行4次(2次MS,2次PL),间隔48小时。在进行运动前40分钟摄入补充剂。在运动前以及每组运动后立即测量心率(HR)和血压(BP)。然后计算速率压力乘积(RPP)以确定估计的MVO。计算每种补充剂的每日RPP和总举重重量(胸部 + 腿部)的平均值。标准化RPP是平均RPP与平均总举重重量的比值。胸部、腿部和总举重次数、运动后标准化RPP(NPRPP)、标准化RPP(NRPP)均无治疗效果(p值分别为0.94、0.86、0.87、0.87、0.43);性别在总举重次数、NPRPP、NRPP方面均无治疗效果(p值分别为0.87、0.95、0.96)。在进行3组直至力竭的胸部和腿部推举练习前40分钟摄入肌肉哨兵对总举重次数或估计的MVO均无影响。这表明,在某些情况下,肌肉哨兵的益处小于制造商所宣称的。