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Whole-body vibration (WBV) augments the musculoskeletal effects of resistance exercise (RE). However, its acute effects on bone turnover markers (BTM) have not been determined. This study examined BTM responses to acute high intensity RE and high intensity RE with WBV (WBV+RE) in young women (n=10) taking oral contraceptives in a randomized, cross-over repeated measures design. WBV+RE exposed subjects to 5 one-minute bouts of vibration (20 Hz, 3.38 peak–peak displacement, separated by 1 minute of rest) prior to RE. Fasting blood samples were obtained before (Pre), immediately post WBV (PostVib), immediately post RE (IP), and 30 minutes post RE (P30). Bone ALP did not change at any time point. TRAP5b significantly (p<0.05) increased from the Pre to PostVib, then decreased from IP to P30 for both conditions. CTX significantly decreased (p<0.05) from Pre to PostVib and from Pre to P30 only for WBV+RE. WBV+RE showed a greater decrease in CTX than RE (-12.6 ± 4.7% vs. -1.13 ± 3.5%). In conclusion, WBV was associated with acute decreases in CTX levels not elicited with resistance exercise alone in young women.

The adaptive mechanisms underlying the well described effect of low-intensity resistance exercise (RE) with blood flow restriction (BFR) to increase muscle strength and muscle mass in humans are not fully understood. Although the influence of Akt/mTOR signalling and a stimulating effect on protein synthesis have been demonstrated, the potential role of myogenic satellite cell activation has not been examined. In the present study BFR RE was hypothesized to activate myogenic satellite cells (SC) expressing Pax-7. PURPOSE:To examine the effect of short-term low-intensity RE with BFR on the activation of Pax7 + SC in relation to muscle cell growth and myonuclei distribution.METHODS: 10 young men (23 ±2 yrs) completed 7 sessions of BFR knee extensor resistance exercise (20% 1-RM load) in 5 days. Training consisted of 4 sets of isolated knee extensor contractions (20% 1-RM loads) to concentric failure during concurrent blood flow restriction (100 mmHg cuff pressure). Muscle biopsies were obtained (VL) at baseline (pre) and day 8 (post 2 days resting). SC expressing Pax-7, myonuclei density and muscle fiber area were assessed by immunohistochemistry.

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