Monitoring muscle damage markers during a four-week downhill walking exercise program

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Strength gain through eccentric isotonic training without changes in clinical signs or blood markers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cardiac autonomic responses induced by a single bout of exercise with flexible pole

Background: Flexible poles are tools used to provide rapid eccentric and concentric muscle contractions. It lacks in the literature studies that analyze acute cardiovascular responses in different exercises performed with this instrument. It was investigated the acute effects of exercise with flexible poles on heart period in healthy women. Methods: The study was performed on 32 women between 18 and 25 years old. It was evaluated the heart rate variability (HRV) in the time (SDNN, RMSSD and pNN50) and frequency domain (HF, LF and LF/HF ratio). The subjects remained at rest for 10 minutes. After the rest period, the volunteers performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 60 minutes and HRV were analyzed. Results: It was observed no significance changes in the time domain (SDNN: p = 0.14; RMSSD: p = 0.8 and pNN50: p = 0.86) and frequency domain indices (LF (nu): 0.4; LF (ms2): p = 0.34; HF (nu): p = 0.4; HF (ms2): p = 0.8 and LF/HF ratio: p = 0.3) between before and after single bout of exercise with flexible pole. Conclusion: A single bout of exercise with flexible pole did not significantly change cardiac autonomic regulation in healthy women.

A single bout of exercise with a flexible pole induces significant cardiac autonomic responses in healthy men

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acute effects of flexible pole exercise on heart rate dynamics

Introduction: Exercise with flexible poles provides fast eccentric and concentric muscle contractions. Although the literature reports significant muscle chain activity during this exercise, it is not clear if a single bout of exercise induces cardiac changes. In this study we assessed the acute effects of flexible pole exercise on cardiac autonomic regulation.Methods: The study was performed on 22 women between 18 and 26 years old. We assessed heart rate variability (HRV) in the time (SDNN, RMSSD and pNN50) and frequency (HF, LF and LF/HF ratio) domains and geometric indices of HRV (RRTri, TINN, SD1, SD2 and SD1/SD2 ratio). The subjects remained at rest for 10 min and then performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 60 min and HRV was analyzed.Results: We observed no significant changes in time domain (SDNN: p=0.72; RMSSD: p=0.94 and pNN50: p=0.92) or frequency domain indices (LF [nu]: p=0.98; LF [ms(2)]: p=0.72; HF [nu]: p=0.98; HF [ms(2)]: p=0.82 and LF/HF ratio: p=0.7) or in geometric indices (RRTri: p=0.54; TINN: p=0.77; SD1 p=0.94; SD2: p=0.67 and SD/SD2: p=0.42) before and after a single bout of flexible pole exercise.Conclusion: A single bout of flexible pole exercise did not induce significant changes in cardiac autonomic regulation in healthy women. (C) 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier Espana, S.L.U. All rights reserved.

Eccentric torque-producing capacity is influenced by muscle length in older healthy adults

Considering the importance of muscle strength to functional capacity in the elderly, the study investigated the effects of age on isokinetic performance and torque production as a function of muscle length. Eleven younger (24.2±2.9years) and seventeen older men (62.7±2.5years) were subjected to concentric and eccentric isokinetic knee extension/flexion at 60°.s-1 and 120°.s-1 through a functional range of motion. The older group presented lower peak torque (Nm) than the young group for both isokinetic contraction types (age effect, p<0.001). Peak torque deficits in the older group were near 30% and 29% for concentric and eccentric contraction, respectively. Concentric peak torque was lower at 120.s-1 than at 60.s-1 for both groups (angular velocity effect, p<0.001). Eccentric knee extension torque was the only exercise tested that showed an interaction effect between age and muscle length (p<0.001), which suggested different torque responses to the muscle length between groups. Compared with the young group, the eccentric knee extension torque was 22% to 56% lower in the older group, with the deficits being lower in the shortened muscle length (22-27%) and higher (33-56%) in stretched muscle length. In older men, the production of eccentric knee strength seems to be muscle length-dependent. At more stretched positions, older subjects lose the capacity to generate eccentric knee extension torque. More studies are needed to assess the mechanisms involved in eccentric strength preservation with aging and its relationship with muscle length.