Temporal response of post-activation performance enhancement induced by a plyometric conditioning activity.

Introduction: To better understand the post-activation performance enhancement (PAPE) effect promoted by a plyometric conditioning activity (CA), the aim of this study was to investigate the temporal response of PAPE after a plyometric CA. Methods: Fourteen healthy and active adults visited the laboratory 3 times, with an interval of 7 days between each visit. On the first day they were familiarized with the countermovement jump (CMJ) test and plyometric CA. In the second and third visits, participants performed either plyometric CA or control (remaining seated) in a crossover design. The CMJ test was performed pre and 1-, 3-, 6-, and 9-min post the plyometric CA or control. The comparisons were performed using the repeated measure two-factor ANOVA and Bonferroni adjustment (significance level adopted P ≤ 0.05). Results: Time (P < 0.01), condition (P < 0.01), and interaction (P < 0.01) effects were reported for CMJ comparisons. For the control condition, CMJ increased at 3 min compared to pre (P = 0.03) and at 3 min compared to 1 min (P = 0.03). For the plyometric CA, CMJ increased at 1- (P < 0.01), 3- (P < 0.01), and 6-min (P = 0.02) compared to pre. For condition comparisons, CMJ was different at 1- (P < 0.01), 3- (P < 0.01), 6- (P < 0.01), and 9-min (P = 0.02). The Effect size of the comparisons of all moments compared to pre was null (d < 0.20) for control and small (d < 0.50) for plyometric CA. Discussion: It is possible to conclude that the plyometric CA promoted a PAPE effect for up to 9-min. Strength and conditioning coaches and practitioners may consider multiple sets of plyometric CA to produce immediate enhancement of power in the lower limbs.

Effects of light-emitting diode therapy on cardiovascular and salivary nitrite responses in postmenopausal women submitted to a single bout of high-intensity interval training.

The aim of the present study was to analyze the effects of light-emitting diode therapy (LEDT) on cardiovascular effort during a single bout of high-intensity interval training (HIIT) and on blood pressure (BP), salivary nitrite, and heart rate variability (HRV) responses after the exercise session in postmenopausal women. Sixteen postmenopausal women between 50 and 70 years of age participated in the present study. The intervention comprised two sessions: placebo plus HIIT and LEDT plus HIIT, with a 14-day interval between sessions. The oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were monitored throughout the HIIT sessions. Salivary samples were taken before, immediately post, and 30' and 60' post-HIIT sessions for nitric oxide (NO) analysis. In addition, HR and BP were checked before, 15 min, 30 min, 45 min, and 60 min post-HIIT sessions. HR data were used to calculate the HRV indices. Cardiovascular parameters during HIIT and BP, HRV, and NO responses were not different between placebo and LEDT conditions (p > 0.05). BP responses increased after compared to pre-exercise (p < 0.01). HRV was impaired post- compared to pre-exercise (p < 0.05). LEDT did not improve physiological performance during HIIT and did not accelerate the recovery of BP and autonomic modulation or change the NO release after exercise in postmenopausal women.

Blood Pressure and Heart Rate Variability Responses to High-Intensity Interval Training in Untrained Postmenopausal Women.

Purpose: The aim of this study was to analyze the blood pressure (BP) and heart rate variability (HRV) responses in untrained postmenopausal women submitted to acute single sessions of high-intensity interval training (HIT). Method: Sixteen postmenopausal women (59.9 ± 5.6 years, 26.7 ± 3.0 kg/m2) participated in a random order of two acute sessions in a balanced crossover format: control without exercise in sitting position or HIT session. BP and heart rate (HR) were recorded before and during 60 min following the sessions. Results: Diastolic (DBP), mean BP (MBP), and double product (DPO) showed interaction (p < .01). DBP, MBP, and DPO increased (p < .01) after HIT but not after the control session. The area under the curve (AUC) of DBP (p = .02) and DPO (p < .01) were different between conditions. Time and frequency indices of HRV presented interaction (p < .05) which impaired these indices post-HIT, but not post-control. The AUC of time and frequency HRV indices were different between conditions. Conclusions: A single session of HIT may increase BP and cardiac stress and cause perturbation of the autonomic function in untrained postmenopausal women.

Effects of Futsal Demands on Serum and Salivary Levels of Trace Elements and Minerals Detected by Total Reflection X-Ray Fluorescence.

The aim of this study was to monitor the circulating and salivary ion concentrations by total reflection X-ray fluorescence (TXRF) in futsal players submitted to the futsal-specific intermittent shuttle protocol (FISP). TXRF may allow identification of changes in ion concentrations induced by physical efforts. Saliva and blood samples of 13 male futsal players were collected before (Pre) and after (Post) the FISP. Salivary and plasma ion levels were detected by TXRF, and differences from Pre to Post (paired t test or Wilcoxon test) and correlations between both biological fluids were determined (P < 0.05). All saliva samples presented phosphorus (P), sulfur (S), chlorine (Cl), potassium (K), calcium (Ca), iron (Fe), zinc (Zn), bromine (Br), and rubidium (Rb). S, Cl, Ca, Fe, Cu, Zn, Br, and Rb were detected in all blood samples. K, Cu, Br, and Rb presented reduced secretion rate from Pre to Post samples (P < 0.05). The salivary concentrations of K (r = - 0.53) and Zn (r = 0.54) were correlated with plasmatic concentrations. After FISP, salivary secretion of S (r = - 0.76), Cl (r = - 0.64), P (r = - 0.67), Mn (r = - 0.74), and Zn (r = 0.69) were correlated with plasma levels. We concluded that TXRF may be used to monitor salivary (P, S, Cl, K, Ca, Fe, Zn, Br, and Rb) and circulating (S, Cl, Ca, Fe, Cu, Zn, Br, and Rb) levels of several elements in futsal athletes. However, an acute bout of futsal-specific physical effort did not significantly imbalance ion concentrations in saliva or plasma.

Isoflavone does not promote additional effects on heart rate variability of postmenopausal women performing combined exercise training: a clinical, controlled, randomized, double-blind study.

The aim of the study was to investigate the effects of ingesting isoflavones associated with combined aerobic and resistance exercise training on heart rate variability (HRV) indices in postmenopausal women. Twenty-eight healthy postmenopausal women performed 10 weeks of combined exercise training associated with isoflavone (n = 16) or placebo (n = 12) supplementation. The RR intervals (RRi) were collected for 20 min using a heart rate monitor. Analysis of HRV was performed in time (mean squared difference of successive RRi (RMSSD), standard deviation of all normal RRi (SDNN), and percentage of adjacent RRi differing by more than 50 ms (pNN50)), frequency (low-frequency percentage (LF%), high-frequency percentage (HF%), and low-/high-frequency ratio (LF/HF)), and nonlinear domains (standard deviation of the instantaneous variability of the beat-to-beat interval (SD1), long-term variability of the continuous RRi (SD2), and their ratio (SD2/SD1)). Student's t test did not show differences between groups in any general baseline characteristic variables. The results of the generalized estimating equation tests did not demonstrate interaction or group effects for any HRV indices. However, the results reported time effects for mean RR (p < 0.001), RMSSD (p = 0.044), and SD1 (p = 0.044), with increases in these indices in response to exercise training. There were no time effects for LF%, HF%, LF/HF, SDNN, pNN50, SD2, or SD2/SD1. In conclusion, isoflavone supplementation did not promote additional effects on HRV indices of postmenopausal women subjected to 10 weeks of combined exercise training. Novelty Combined training improves heart rate variability in postmenopausal women. Isoflavone supplementation did not promote additional effects on heart rate variability in postmenopausal women.

Relationship Between Training Volume and Ratings of Perceived Exertion in Swimmers.

The markers of external training load (ETL), distance and intensity, do not take into account the athletes' psychophysiological stress, i.e., internal training load (ITL). Thus, the aim of this study was to evaluate the relationship between ETL and ITL using the rating of perceived exertion (RPE) and session-RPE in swimmers. Seventeen young swimmers (10 male, 15.8 ± 0.87 yr and 7 female, 15.1 ± 0.46 yr) belonging to one national level youth team took part in this study over 4 wk. The external training load was planned using swimming distance (in meters) at seven different training intensities. Swimmers' RPE was assessed 30 min after each training session. Session-RPE was calculated by multiplying RPE by session duration (min). The relationship between the variables was analyzed with Pearson correlations and a multiple linear regression was performed to predict the session-RPE as a function of the independent variables (aerobic and anaerobic volume). The swimming distance at different intensities correlated strongly with RPE and very largely with session-RPE (.64, p < .05 and .71, p < .05, respectively). Regression analysis indicated that the aerobic and anaerobic volumes together explained more than 50% of the ITL variability. In conclusion, the swimming distance in each training session was significantly associated with RPE and session-RPE in swimmers. In other words, based on these results, the use of high-volume training at lower intensities affects the RPE and Session-RPE more than the anaerobic volume.