The effects of a commercially available botanical supplement on strength, body composition, power output, and hormonal profiles in resistance-trained males
 
 
Journal Title (Medline/Pubmed accepted abbreviation): J Int Soc Sports Nutr
Year: 2010
Volume: 7
Number:
Page numbers: 34
doi: 10.1186/1550-2783-7-34

Summary of Background and Research Design

Background:In preclinical and clinical studies, extracts of the fenugreek plant (ie, Trigonella foenum-graecum) lowered blood glucose levels and enhanced insulin sensitivity. Animal models report that ingesting fenugreek seeds improved lipid profiles by lowering low-density lipoprotein (LDL) and triglyceride levels and increasing high-density lipoprotein (HDL) levels. Additionally, animal studies demonstrated anabolic and ergogenic properties of fenugreek. However, there are no clinical trials that have evaluated the effects of fenugreek on human strength, exercise performance, or hormonal changes.

Hypothesis/purpose of study: The purpose of this study was to determine the effects of a fenugreek extract on strength, body composition, power output, and hormonal profiles in resistance-trained males.

Subjects:Male volunteers with more than 1 year's history in resistance training participated in the trial. Volunteers in the placebo group (PLA; n = 23) had a mean age of 20 year, body fat of 17%, and weight of 85 kg. Likewise, volunteers in the fenugreek group (FEN; n = 26) had a mean age of 21 years, body fat of 19%, and weight of 90 kg.

Experimental design: Randomized, double-blind, controlled

Treatments and protocol: Male subjects, matched by total body weight, were randomized to receive either daily placebo or 500 mg fenugreek extract supplementation (morning consumption, except for training days where taken prior to work out). Following a familiarization/practice session, subjects returned to perform a baseline testing session consisting of 1 repetition of maximum weight lifts on the bench press and 45° leg press (warm-up repetitions at 50% and 70% of expected maximum) with a 10-minute rest interval in between. In addition, subjects performed 30 minutes of cycling after a 15-minute rest from the strength assessments. A training regimen (4 days/week) and supplementation were then assigned. Subjects kept a food dairy for 4 days, refrained from exercise for 48 hours, and fasted for 12 hours before baseline and before each exercise testing session. Testing sessions were conducted after 4 and 8 weeks of training and supplementation. In addition to power output, body composition, strength (one repetition maximum [1-RM]), and muscular endurance (number of repetitions at 80% 1-RM) were assessed at each testing session. Hormone levels of free testosterone, dihydrotestosterone, insulin, leptin, cortisol, and estradiol were determined at each testing session. Chemistry profiles, hepatic function, and blood cell counts were also monitored.

Summary of research findings:
  • No differences were noted between the treatment groups for caloric intake, training volume, chemistry profiles, hepatic function, or hematologic parameters at baseline, week 4, or week 8.
  • There were no changes in body weight between groups at any timepoint.
  • There was a significant group x time interaction (P < .001) for body fat percentage. After multiple comparisons testing, there were significant decreases for FEN vs PLA at 4 weeks (-1.6% vs -0.3% compared with baseline) and 8 weeks (-2.3% vs -0.4% compared with baseline) (P < .001 in each case).
  • For lean mass, there was a nonsignificant increase for FEN vs PLA (group x time P = .057).
    • NOTE: Figures in Table 3 for lean mass were labeled as “kg,” but the numbers reported probably represent pounds.
  • For bench-press 1-RM, there was a significant group x time interaction (P = .008), but multiple comparisons did not show the increases for FEN vs PLA to be significant at any timepoint.
    • No significant changes were observed for number of repetitions at 80% 1-RM.
  • For leg-press 1-RM, there was a significant group x time interaction (P < .001), and multiple comparisons revealed a significant increase for FEN vs PLA at 8 weeks (P = .019).
    • No significant changes were observed for number of repetitions at 80% 1-RM.
  • There were no significant changes in peak power output. For mean power output, there was a significant group x time interaction (P = .036), but multiple comparisons did not show the increases for FEN vs PLA to be significant at any timepoint.
  • There were no meaningful changes in hormone levels between the 2 treatments.
  • There were no changes between groups for clinical safety variables.
    • Several participants experienced gastrointestinal discomfort and/or mild stomachaches, but these problems were all minor and may or may not have been related to the treatments.

Interpretation of findings/Key practice applications:

Fenugreek, in conjunction with resistance training, produced modest improvements in body composition. There was also a considerable improvement in leg-press 1-RM for FEN vs PLA. Although the mechanism of action is not established, fenugreek has the potential to improve body fat percentage over long-term resistance training. Interestingly, the reported anabolic properties of fenugreek were not supported by the hormone results of this study. However, further research is needed to evaluate different fenugreek extracts and dosages before discounting any anabolic properties. It is also not known whether fenugreek use over a period longer than 8 weeks or in untrained subjects would accentuate the potential benefits of fenugreek supplementation.
Google Tracking Google Plus Tracking Twitter Tracking