Fast-velocity Resistance Training Improves Force Development and Mobility in Multiple Sclerosis.

This study aimed to analyze the benefits of a lower-limb fast-velocity concentric resistance training on rate of force development, mobility, and quality of life in people with Multiple Sclerosis. A randomized controlled trial was conducted in 30 people with Multiple Sclerosis, who were randomly assigned to either an experimental (n=18) or a control (n=12) group. The experimental group carried out 10-weeks of fast-velocity concentric resistance training, while the control group did not perform any intervention. Early and late rate of force development during knee extension in both legs, sit-to-stand and Timed Up and Go tests and quality life questionnaire were evaluated before and after intervention. The training program evoked an increase in early rate of force development in experimental group (0-30; Rightleg: 63.9%, p<0.001; ES=-1.4; Leftleg: 52.7%, p<0.001; ES=-1.0) compared to control group (showed modest increases). Furthermore, experimental group improved mobility after training (Sit-to-stand: 22.2%, p<0.001; ES=1.0; Timed Up and Go Test: 10.1%, p<0.001; ES=1.1) and increased the perception of quality of life after training, while control showed no changes. The fast-velocity concentric resistance training has the potential to improve early rate of force development and mobility after 10-weeks of training. In addition, the increase in self-perceived quality of life following this training modality demonstrates promising results in the Multiple Sclerosis population.

High-intensity Interval Training in Different Exercise Modes: Lessons from Time to Exhaustion.

To provide information for high-intensity interval training (HIIT) load, we compared the temporal variables of VO2 response at, and after, a time sustained at the exercise intensity corresponding to VO2max (Tlim) in different exercise modes. Forty-five trained male swimmers (11), rowers (13), runners (10) and cyclists (11) completed an incremental protocol to determine the velocity (vVO2max) or power (wVO2max) at VO2max and a square wave exercise from rest to 100% of vVO2max/wVO2max. The temporal variables of VO2 response were examined using a breath-by-breath gas analyzer. VO2 responses were not different between exercise modes, except for the percentage of VO2max at 50% of Tlim, which was ~6% higher in rowing compared to cycling (97.70±2.90 vs 92.40±5.69%, p=0.013). During the recovery period, both swimmers and rowers evidenced higher percentages of VO2max compared to cyclists at 30 s (65.1±10.4 and 65.7±5.6 vs 52.7±5.6%) and 60 s (41.7±10.8 and 38.4±5.4 vs 30.4±1.8%) time periods, all for p<0.01. Furthermore, swimmers presented higher time values to reach 50% VO2max compared to runners and cyclists (51.1±15.6 vs 38.1±6.7 and 33.8±4.7%; p<0.001). When training at 100% of VO2max intensity, fixed intervals for HIIT could be set freely. However, recovery periods based on time or intensity are exercise-mode dependent.

Comparative analysis of the ground reaction forces, during the support phase, in a group of pregnant women on their 3rd trimester of pregnancy and in a group pf not pregnant women

To analyze and compare the Ground Reaction Forces 9GRF), during the stance phase of walking in pregnant women in the 3rd trimester of pregnancy, and no pregnant women. Methods: 20 women, 10 pregnant and 10 non pregnant, voluntarily took part in this study.: GRF were measured (1000Hz) using a force platform (BERTEC 4060-15), an amplifier (BERTEC AM 6300) and an analogical-digital converter of 16 Bits (Biopac). Results: The study showed that there were significant differences among the two groups concerning absolute values the most significant differences were verified in the maximuns values of vertical force (Fz3,Fz1) and in the impulse of the antero-posterior force (Fy2), taxes of growth of the vertical force, and in the period of time for the antero-posterior force 9Fy) be null. Conclusions: It is easier for the pregnant to continue foeward movement (push-off phase). O smaller growth rates in what concerns to the maximum of the vertical force (Fz1) for the pregnant, can be associated with a slower speed of gait, as an adaptation stretegy to maintain the balance, to compensate the alterations in the position of ther center of gravity due to the load increase. The date related to the antrero-posterior component of the force (Fy), shows that there is a significant difference between the pregnant woman's left foot, which accuses a different functional behavior in each one of the feet, during the propulsion phase.