Metabolic responses to whole-body vibration: effect of frequency and amplitude.

PURPOSE: This study assessed the effect of whole-body vibration (WBV) of varying frequency and amplitude on metabolic responses during WBV treatment and subsequent aerobic exercise. METHODS: Eight men and eight women (21.0 ± 1.9 years) underwent one no-WBV (NV) and six WBV at 30 Hz/low amplitude (30L), 30 Hz/high amplitude (30H), 40 Hz/low amplitude (40L), 40 Hz/high amplitude (40H), 50 Hz/low amplitude (50L), and 50 Hz/high amplitude (50H). During each protocol, subjects performed ten sets of ten body weight squats with 1-min rest period between sets on a vibration platform with a load that represented one of the six frequency-amplitude combinations. Each WBV treatment was immediately followed by 20 min of cycle exercise at 65 % VO2peak. Oxygen uptake (VO2) and rates of carbohydrate (COX) and fat oxidation (FOX) were measured during both the WBV session and subsequent exercise. RESULTS: During WBV, VO2 was higher (p < 0.05) in 40H, 50L and 50H than NV and in 50H than 30L, 30H and 40L. COX was higher (p < 0.05) in 40H, 50L, and 50H than NV, whereas FOX remained indifferent across all protocols. During subsequent exercise, VO2 was higher (p < 0.05) in 50L and 50H than NV and in 50H than 30L. No between-protocol differences were seen for COX or FOX. CONCLUSION: WBV combined with body weight squats can augment VO2 at 40 Hz of high amplitude and 50 Hz of both low and high amplitudes. This metabolic potentiation remains in effect during subsequent aerobic exercise. WBV did not affect fat oxidation across all vibratory loads.

Acute Resistance Exercise Performance Is Negatively Impacted by Prior Aerobic Endurance Exercise.

Ratamess, NA, Kang, J, Porfido, TM, Ismaili, CP, Selamie, SN, Williams, BD, Kuper, JD, Bush, JA, and Faigenbaum, AD. Acute resistance exercise performance is negatively impacted by prior aerobic endurance exercise. J Strength Cond Res 30(10): 2667-2681, 2016-The purpose of the present study was to examine acute resistance exercise (RE) performance after 4 different aerobic endurance (AE) protocols. Eleven healthy, resistance-trained men (21.0 ± 1.2 years) performed a control RE protocol and 4 RE protocols 10 minutes after different AE protocols in random sequence. The RE protocol consisted of 5 exercises (high pull, squat, bench press, deadlift, and push press) performed for 3 sets of 6-10 repetitions with 70-80% of one repetition-maximum (1RM) with 3-minute rest intervals in between sets. The AE protocols consisted of treadmill running at velocities corresponding to: (a) 60% of their V[Combining Dot Above]O2 reserve (V[Combining Dot Above]O2R) for 45 minutes (P1); (b) 75% of their V[Combining Dot Above]O2R for 20 minutes (P2); (c) 90-100% of V[Combining Dot Above]O2R in 3-minute intervals (1:1 ratio) for 5 sets (P3); and (d) 75% of V[Combining Dot Above]O2R (4.5 mph) uphill (6-9% grade) for 20 minutes (P4). Completed repetitions, average power and velocity, heart rate (HR), and ratings of perceived exertion (RPE) were assessed each set. Protocols P1-P4 resulted in 9.1-18.6% fewer total repetitions performed compared with the control RE protocol with the squat experiencing the greatest reduction. Average power and velocity were significantly reduced for the high pull, squat, and bench press after most AE protocols. Ratings of perceived exertion values for the high pull and squat were significantly higher in P1-P4 compared with control. Heart rate was significantly higher during RE after P1-P4 compared with control by 4.3-5.5%. These results indicate acute RE performance is significantly compromised in healthy men after AE exercise of different type, intensity, and duration with largest reductions observed after high-intensity interval exercise.