Four weeks of supplementation with a multi-nutrient product increases lean mass and muscular performance in resistance trained men

Methods Using a randomized, double-blind design, 30 healthy men (mean ± SD age, height, weight, % body fat: 25.7 ± 6.7 y, 178.0 ± 6.4 cm, 84.4 ± 10.7 kg, 18.9 ± 7.0%) were matched for age, resistance training history, daily caffeine intake, weekly meat consumption, bench press strength, bench press endurance, and percent body fat and then randomly assigned to ingest 2–3 scoops per day of SP250 or placebo for one month. Body composition (DEXA), muscular performance (1-RM bench press and repetitions to failure [RTF: 3 sets × baseline body weight, 60-sec rest between sets]), and clinical blood chemistries were measured at baseline and after four weeks of supplementation and training. Subjects were required to maintain their normal dietary habits and follow a specific, progressive overload resistance training program (4-d/wk, upper body/ lower body split) during the study. Data were analyzed via repeated-measures ANOVA and (where necessary) Fisher LSD post-hoc tests. Statistical significance was set a priori at p ≤ 0.05. Results Significant between group differences over time were noted in: RTF (SP250: +28.2%; 29.1 ± 15.8 [wk 0] to 37.3.0 ± 20.0 reps [wk 4] vs. placebo: +12.0%; 29.1 ± 12.1 [wk 0] to 32.6 ± 12.1 reps [wk 4], P < 0.04), lean mass (SP250: +2.1%; 66.58 ± 8.57 [wk 0] to 68.00 ± 9.16 kg [wk 4] vs. placebo: +0.3%; 59.93 ± 3.62 [wk 0] to 60.08 ± 3.94 kg [wk 4], P < 0.01), upper extremity lean mass (SP250: +5.5%; 9.27 ± 2.34 [wk 0] to 9.78 ± 2.62 kg [wk 4] vs. placebo: +0.3%; 7.88 ± 1.27 [wk 0] to 7.90 ± 1.51 kg [wk 4], P < 0.03), and % body fat (SP250: -0.9%; 22.8 ± 8.2 [wk 0] to 21.9 ± 8.4% [wk 4] vs. placebo: +0.9%; 20.0 ± 6.6 [wk 0] to 20.9 ± 7.7% [wk 4], P < 0.04) (Figure 1). Both groups had significant (~6%) increases in 1-RM bench press from wk 0 to wk 4, however, no betweengroup differences were noted (P < 0.30). No changes in systemic hemodynamics (heart rate, systolic and diastolic blood pressures) or clinical blood chemistries (glucose, blood urea nitrogen, creatinine, sodium, potassium, serum protein, albumin, globulin, A:G ratio, bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, total cholesterol, HDL-cholesterol, triacylglycerol, VLDL-cholesterol, LDL-cholesterol) were noted between groups over time.