Sex-specific response to whole-body vibration training: a randomized controlled trial.

A few studies have indicated that males and females respond differently to whole-body vibration (WBV) training. However, the existing insights are still insufficient and they cannot be transferred to sex-specific practice planning. To evaluate the effect of 5-week WBV training on neuromuscular [countermovement jump (CMJ), squat jump (SJ)] and cardiovascular [heart rate and blood pressure] data, taking into account sex-specific effects. This is a comparative experimental study including 96 healthy adults, divided into two groups: a WBV group (25 females and 24 males) and a control group (27 females and 20 males). The participants attended nine to ten training sessions (twice a week for 5 weeks), each lasting approximately 30 min. Both groups performed the same exercise routine on the vibration training device. For the WBV group, the training device was vibrating during the whole training session, including the breaks. For the control group, it was turned off. Maximum jump height (H, cm) and maximum relative power (MRP, kW/kg) were noted during CMJ and SJ performed on a force plate. Resting (sitting) heart rate (bpm) and blood pressure (mmHg) were measured twice, before and after the intervention. For each parameter, Δdata (= before - after) was calculated. Interactive effects of sex (2) vs group (2) vs session (2) were noted only in males and they only concerned ΔSJMPR and ΔCMJH: compared to the control group, the WBV group had better ΔSJMPR (1.39 ± 3.05 vs -2.69 ± 4.49 kW/kg, respectively) and ΔCMJH (0.50 ± 6.14 vs -4.42 ± 5.80 cm, respectively). No sex-specific effect of WBV on neuromuscular (CMJ and SJ) or cardiovascular (heart rate and blood pressure) data was found.

Repeated-sprints exercise in daylight fasting: carbohydrate mouth rinsing does not affect sprint and reaction time performance.

To determine the effect of carbohydrate mouth rinsing (CHO-MR) on physical and cognitive performance during repeated-sprints (RS) after 3 days of intermittent fasting (abstaining from food and fluid 14 h per day). In a randomized and counter-balanced manner 15 active healthy males in a fasted state performed a RS-protocol [RSP; 2 sets (SET1 and SET2) of 5×5 s maximal sprints, with each sprint interspersed with 25 s rest and 3 min of recovery between SET1 and SET2] on an instrumented non-motorized treadmill with embedded force sensors under three conditions: i) Control (CON; no-MR), ii) Placebo-MR (PLA-MR; 0% maltodextrin) and iii) CHO-MR (10% maltodextrin). Participants rinsed their mouth with either 10 mL of PLA-MR or CHO-MR solution for 5 s before each sprint. Sprint kinetics were measured for each sprint and reaction time (RTI) tasks (simple and complex) were assessed pre-, during- and post-RSP. There was no statistical main effect of CHO-MR on mean power, mean speed, and vertical stiffness during the sprints between the PLA-MR and CON condition. Additionally, no statistical main effect for CHO-MR on accuracy, movement time and reaction time during the RTI tasks was seen. CHO-MR did not affect physical (RSP) or cognitive (RTI) performance in participants who had observed 3 days of intermittent fasting (abstaining from food and fluid 14 h per day).

Repeated Sprints in Fasted State Impair Reaction Time Performance.

OBJECTIVE: The aim of this study was to assess the effects of 3-day Islamic intermittent fasting (3d-IF) on cognitive performance and serum levels of neurotrophic factors (brain-derived neurotrophic factor [BDNF] and vascular endothelial growth factor [VEGF]) before and after repeated sprints. METHODS: Twenty-one physically active male Muslims (29.8 ± 5.9 years, exercising 4 ± 1.5 times/week) were randomly assigned to one of 2 experimental sessions: the control or nonfasting session (CS) or the fasting session (FS). These 2 sessions occurred 7 days apart in a counterbalanced crossover design. In both conditions, the test was performed at the same time of day, approximately 1 hour before sunset. In the FS, the test occurred on the third day of the 3d-IF and involved the participants' performance of the following: (a) two series of 5 maximal 5-second sprints and (b) 2 cognitive tasks: One Touch Stockings (OTS) and reaction time (simple and complex RTI). RESULTS: In both conditions, the participants' reaction times during the RTI test were similar at the pre- and mid-exercise points, but postexercise, simple and complex reaction times were higher in FS compared to CS (p = 0.045, effect size [ES] = 0.21 and p = 0.006, ES = 0.41, respectively). However, OTS performance and serum levels of neurotrophic factors were not influenced by the 3d-IF. CONCLUSION: Simple and complex reaction times during the RTI test were negatively affected by the 3d-IF after 2 bouts of intensive repeated sprints.

Electromagnetic Induction for Treatment of Unspecific Back Pain: A Prospective Randomized Sham-Controlled Clinical Trial.

OBJECTIVE: To evaluate the effects of high-energy pulsed electromagnetic fields on unspecific back pain. METHODS: A prospective, randomized, sham-controlled clinical trial with repeated measurements was performed. The study included 5 visits (V0 to V4) with 3 interventions during V1, V2 and V3. Sixty-one patients aged between 18 and 80 years with unspecific back pain (acute inflammatory diseases and specific causes were reasons for exclusion) were included. The treatment group (n = 31) received 1-2 pulses/s, with an intensity of 50 mT, and an electric field strength of at least 20 V/m on 3 consecutive weekdays for 10 min each time. The control group (n = 30) received a comparable sham therapy. Pain intensity (visual analogue scale), local oxyhaemoglobin saturation, heart rate, blood pressure, and perfusion index were evaluated before (b) and after (a) V1 and V3 interventions. Change in visual analogue scale for V1 (ChangeV1a-b) and V3 (ChangeV3a-b), and ChangeData between V3a and V1b (ChangeV3a-V1b) for the remaining data were calculated (results were mean (standard deviation) (95% confidence interval; 95% CI)). RESULTS: Concerning the visual analogue scale: (i) compared with the control group, the treatment group had higher ChangeV1a-b (-1.25 (1.76) (95% CI -1.91 to -0.59) vs -2.69 (1.74) (95% CI -3.33 to -2.06), respectively), and comparable Change V3a-b (-0.86 (1.34) (95% CI -1.36 to -0.36) vs -1.37 (1.03) (95% CI -1.75 to 0.99), respectively); and (ii) there was a significant marked decrease in Change V3a-1b in the treatment group compared with the control group (-5.15 (1.56) (95% CI -5.72 to -4.57) vs -2.58 (1.68) (95% CI -3.21 to -1.96), p = 0.001, respectively). There was no significant ChangeV3a-V1b in local oxyhaemoglobin saturation, heart rate, blood pressure or perfusion index between the 2 groups and for the same group (before vs after). CONCLUSION: Non-thermal, non-invasive electromagnetic induction therapy had a significant and rapid influence on unspecific back pain in the treatment group.

Effects of Ramadan intermittent fasting on North African children's heart rate and oxy-haemoglobin saturation at rest and during sub-maximal exercise.

AIM: To examine the effects of Ramadan intermittent fasting (RIF) on the heart rate (HR) and oxyhaemoglobin saturation levels (oxy-sat) of boys at rest and during a six-minute walking test (6MWT). METHODS: Eighteen boys (age: 11.9 ± 0.8 years, height: 153.00 ± 8.93 cm, body mass: 55.4 ± 18.2 kg), who fasted the entire month of Ramadan in 2012 for the first time in their lives, were included. The experimental protocol comprised four testing phases: two weeks before Ramadan (pre-R), the end of the second week of Ramadan (R-2), the end of the fourth week of Ramadan (R-4), and 10 to 12 days after the end of Ramadan (post-R). During each phase, participants performed the 6MWT at approximately 15:00. HR (expressed as percentage of maximal predicted HR) and oxy-sat (%) were determined at rest and in each minute of the 6MWT. RESULTS: R-4 HR values were lower than those of (1) pre-R (in the second minute), (2) R-2 (in the first and second minutes), and (3) post-R (in the first, second, fourth, fifth and sixth minutes). R-2 oxy-sat values were higher than those of pre-R (in the third minute) and those of post-R (in the fifth minute). Post-R oxy-sat values were lower than those of pre-R and R-4 in the fifth minute. These oxy-sat changes were not clinically significant since the difference was less than five points. CONCLUSION: In non-athletic children, their first RIF influenced their heart rate data but had a minimal effect on oxy-sat values.

Three Days of Intermittent Fasting: Repeated-Sprint Performance Decreased by Vertical-Stiffness Impairment.

PURPOSE: To examine the effects of 3 d of intermittent fasting (3d-IF: abstaining from eating/drinking from dawn to sunset) on physical performance and metabolic responses to repeated sprints (RSs). METHODS: Twenty-one active males performed an RS test (2 sets: 5 × 5-s maximal sprints with 25 s of recovery between and 3 min of recovery between sets on an instrumented treadmill) in 2 conditions: counterbalanced fed/control session (CS) and fasting session (FS). Biomechanical and biochemical markers were assessed preexercise and postexercise. RESULTS: Significant main effects of IF were observed for sprints: maximal speed (P = .016), mean speed (P = .015), maximal power (P = .035), mean power (P = .049), vertical stiffness (P = .032), and vertical center-of-mass displacement (P = .047). Sprint speed and vertical stiffness decreased during the 1st (P = .003 and P = .005) and 2nd sprints (P = .046 and P = .048) of set 2, respectively. Postexercise insulin decreased in CS (P = .023) but not in FS (P = .230). Free-fatty-acid levels were higher in FS than in CS at preexercise (P < .001) and at postexercise (P = .009). High-density lipoprotein cholesterol (HDL-C) was higher at postexercise in FS (1.32 ± 0.22 mmol/L) than in CS (1.26 ± 0.21 mmol/L, P = .039). The triglyceride (TG) concentration was decreased in FS (P < .05) compared with CS. CONCLUSIONS: 3d-IF impaired speed and power through a decrease in vertical stiffness during the initial runs of the 2nd set of RS. The findings of the current study confirmed the benefits of 3d-IF: improved HDL-C and TG profiles while maintaining total cholesterol and low-density lipoprotein cholesterol levels. Moreover, improving muscle power might be a key factor to retain a higher vertical stiffness and to partly counteract the negative effects of intermittent fasting.