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WOS: 000387111600008, PubMed ID: 28149412, It is important to verify the old findings of Cumming (1972) and Goldberg and Shephard (1980) who showed that stroke volume (SV) may be higher during recovery rather than during exercise, in order to organize the number of intervals throughout training sessions. The purpose of this study was to re-evaluate individual SV responses to various upright cycling exercises using the nitrous-oxide rebreathing method. Nine moderate to well-trained male athletes volunteered to take part in the study (maximal O-2 uptake (VO2max): 60.2 +/- 7 mL.min(-1).kg(-1)). Workloads ranging from 40-100% of VO2max were applied to determine individual peak SV (SVpeak) response. Results showed that SV responses were higher during exercise compared to recovery in all exercise loads from 40-100% of VO2max. Mean SV responses to individual SVpeak loads were also higher during exercise compared to recovery (122.9 +/- 2.5 versus 105.3 +/- 5.93 mL). The highest SV responses to 10 min exercises of 40-70% of VO2max were obtained in the 5th or 7.5th min of each stage (p= 0.05). Meanwhile, during 5 min exercises between 80-100% of VO2max, peak SV responses were observed in the 3rd min of loading (p= 0.05). In conclusion, individual SVpeak levels encountered over wide exercise intensity ranges showed that SVpeak development may also be correlated to exercise intensity corresponding to individual SVpeak loads.

WOS: 000330209300005, PubMed ID: 24511340, The purpose of this study was to investigate the short-term effects of static stretching, with vibration given directly over Achilles tendon, on electro-myographic (EMG) responses and vertical jump (VJ) performances. Fifteen male, college athletes voluntarily participated in this study (n=15; age: 22 +/- 4 years old; body height: 181 +/- 10 cm; body mass: 74 +/- 11 kg). All stages were completed within 90 minutes for each participant. Tendon vibration bouts lasted 30 seconds at 50 Hz for each volunteer. EMG analysis for peripheral silent period, H-reflex, H-reflex threshold, T-reflex and H/M ratio were completed for each experimental phases. EMG data were obtained from the soleus muscle in response to electro stimulation on the popliteal post tibial nerve. As expected, the dynamic warm-up (DW) increased VJ performances (p=0.004). Increased VJ performances after the DW were not statistically substantiated by the EMG findings. In addition, EMG results did not indicate that either static stretching (SS) or tendon vibration combined with static stretching (TVSS) had any detrimental or facilitation effect on vertical jump performances. In conclusion, using TVSS does not seem to facilitate warm-up effects before explosive performance.