MusclePharm Sports Science Institute, MusclePharm Corp., 4721 Ironton St. Building A, Denver, CO 80239 USA ; Metropolitan State University, Denver, CO USA.
MusclePharm Sports Science Institute, MusclePharm Corp., 4721 Ironton St. Building A, Denver, CO 80239 USA.
J Int Soc Sports Nutr. 2015 Feb 21;12:12. doi: 10.1186/s12970-015-0074-y. eCollection 2015.
Pre-workout supplements (PWS) have increased in popularity among athletic populations for their purported ergogenic benefits. Most PWS contain a "proprietary blend" of several ingredients, such as caffeine, beta-alanine, and nitrate in undisclosed dosages. Currently, little research exists on the safety and potential side effects of chronic consumption of PWS, and even less so involving female populations. Therefore, the purpose of the present study was to examine the safety of consuming a dose-escalated PWS over a 28-day period among active adult females.
34 recreationally active, adult females (27.1 ± 5.4 years, 165.2 ± 5.7 cm, 68.2 ± 16.0 kg) participated in this study. Participants were randomly assigned to consume either 1 (G1) or 2 (G2) servings of a PWS daily or remain unsupplemented (CRL) for a period of 28 days. All were instructed to maintain their habitual dietary and exercise routines for the duration of the study. Fasting blood samples, as well as resting blood pressure and heart rate, were taken prior to and following the supplementation period. Samples were analyzed for hematological and clinical chemistry panels, including lipids.
Significant (p < 0.05) group by time interactions were present for absolute monocytes (CRL -0.10 ± 0.10; G1 + 0.03 ± 0.13; G2 + 0.01 ± 0.12×10E3/uL), MCH (CRL -0.13 ± 0.46; G1 + 0.36 ± 0.52; G2 -0.19 ± 0.39 pg), creatinine (CRL 0.00 ± 0.05; G1 -0.06 ± 0.13; G2 -0.14 ± 0.08 mg/dL), eGFR (CRL -0.69 ± 5.97; G1 + 6.10 ± 15.89; G2 + 14.63 ± 7.11 mL/min/1.73), and total cholesterol (CRL -2.44 ± 13.63; G1 + 14.40 ± 27.32; G2 -10.38 ± 15.39 mg/dL). Each of these variables remained within the accepted physiological range. No other variables had significant interactions.
The present study confirms the hypothesis that a PWS containing caffeine, beta-alanine, and nitrate will not cause abnormal changes in hematological markers or resting vital signs among adult females. Although there were statistically significant (p < 0.05) group by time interactions for absolute monocytes, MCH, creatinine, eGFR, and total cholesterol, all of the results remained well within accepted physiological ranges and were not clinically significant. In sum, it appears as though daily supplementation with up to 2 servings of the PWS under investigation, over an interval of 28 days, did not adversely affect markers of clinical safety among active adult females.
在运动人群中， 健身补剂（PWS）因其所谓的运动表现益处而越来越受欢迎。大多数健身补剂含有“专利混合”的几种成分，如咖啡因、β-丙氨酸和硝酸盐，剂量未公开。目前，关于长期摄入健身补剂的安全性和潜在副作用的研究很少，涉及女性人群的研究则更少。因此，本研究的目的是在 28 天的时间内，检查活跃成年女性摄入递增剂量的健身补剂的安全性。
34 名有规律运动的成年女性（27.1±5.4 岁，165.2±5.7cm，68.2±16.0kg）参与了这项研究。参与者被随机分配每天服用 1 份（G1）或 2 份（G2）健身补剂，或不服用补剂（CRL），持续 28 天。所有参与者在研究期间都被要求保持他们的习惯性饮食和运动习惯。在补充期前后，抽取空腹血样，测量静息血压和心率。样本用于分析血液学和临床化学指标，包括血脂。
绝对单核细胞（CRL -0.10±0.10；G1+0.03±0.13；G2+0.01±0.12×10E3/uL）、平均红细胞血红蛋白量（MCH）（CRL -0.13±0.46；G1+0.36±0.52；G2-0.19±0.39pg）、肌酐（CRL 0.00±0.05；G1-0.06±0.13；G2-0.14±0.08mg/dL）、肾小球滤过率（eGFR）（CRL-0.69±5.97；G1+6.10±15.89；G2+14.63±7.11mL/min/1.73）和总胆固醇（CRL-2.44±13.63；G1+14.40±27.32；G2-10.38±15.39mg/dL）等变量均出现了显著的组间时间交互作用（p<0.05）。这些变量均在可接受的生理范围内。没有其他变量出现显著的交互作用。
本研究证实了以下假设，即含有咖啡因、β-丙氨酸和硝酸盐的健身补剂不会导致成年女性的血液学标志物或静息生命体征出现异常变化。虽然绝对单核细胞、MCH、肌酐、eGFR 和总胆固醇等变量的组间时间交互作用具有统计学意义（p<0.05），但所有结果均在可接受的生理范围内，且无临床意义。总之，在 28 天的时间内，每天摄入最高 2 份研究中使用的健身补剂，似乎不会对活跃成年女性的临床安全性标志物产生不利影响。
