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Purpose: The objective of this study was to evaluate a plyometric conditioning activity (3 sets of 5 countermovement jumps, [CA]) for twitch properties and voluntary knee extension. Methods: After a familiarization session, fourteen highly trained sprint athletes, 12 men (23.25 ± 7.17 years) and 2 women (23.0 ± 2.8 years) performed 2 experiments, each in a randomized order (crossover design). In one experiment, the time-course of twitch contractile properties was evaluated with and without the previous CA at 2, min intervals to 10 min of recovery. In the second session, maximal voluntary knee extension was evaluated at the same recovery intervals, for control and experimental condition in random order. Results: Mixed-model ANOVA with Bonferroni post-hoc revealed significant differences between pre-test and 2 min (p 0.05). No significant difference was observed for voluntary RTD following CA. Conclusion: The plyometric CA increased twitch peak torque and RTD consistent with PAP; however, there was no effect of CA on voluntary RTD of knee extension at any time after the plyometric CA. Even with PAP confirmed, we observed that the CA fails to improve isometric RTD of quadriceps femoris muscles. HighlightsA plyometric CA significantly increased twitch peak torque (at 2 and 4 min) and twitch rate of torque development (at 2 min) of quadriceps femoris muscles, indicating postactivation potentiation (PAP).No effect was observed for twitch contraction time and ½ relaxation time after the CA.No improvement was observed on voluntary rate of torque development evaluated at the same time intervals.

Summary The linear tapering method duration can be determinant for sport performance. Objective The objective of this study was to analyze the effect of linear tapering duration method on anaerobic power and capacity in road cyclists. Materials and methods Seventeen male road cyclists, aged between 18 and 30 years were randomly selected within the study criteria. Participants performed 16 weeks of training, adopting the undulating periodization with weekly variation of the training load. The tapering phase lasted 4 weeks, using the linear tapering method, reducing only the training volume: 85% in the first, 70% in the second, 55% in the third and 40% in the fourth week. The Wingate test was used to evaluate anaerobic power and capacity. Wingate was performed by the cyclists before the start of the season, at the end of the last week of each mesocycle (Preparatory I, Specific I and Specific II) and at the end of each week in the tapering phase. Results The results revealed a time effect for anaerobic power (P 0.05), finishing with attenuation in the fourth week of tapering (P = 0.01). Conclusion It was concluded that 2 weeks of tapering was enough to improve the anaerobic power and capacity in road cyclists.

Purpose This study compared sex-related affective responses during resistance training performed to concentric failure. Methods The study was a non-randomized trial (quasi-experimental study). Well-trained young participants were allocated into two groups according to sex (Women, n = 7, 21.1 ± 6.0 years, 57.6 ± 5.0 kg; and Men, n = 7, 28.3 ± 5.7 years, 88.3 ± 11.4 kg). Participants visited the laboratory three times: 1) 12-repetition maximum; 2–3) resistance training to concentric failure sessions. Perceptual measures were assessed before, during, and immediately after the resistance training sessions. The following were assessed: a) rating of perceived exertion for effort (RPE-E) and discomfort (RPE-D), b) feeling scale, c) physical activity affect scale (PAAS), d) felt arousal scale, and e) physical activity enjoyment scale (PACES). Results High levels of RPE-E and RPE-D were reported without between-groups differences (p > 0.218). Women reported a reduction in the feeling scale (p = 0.001) whereas men did not (p > 0.680). Larger effect sizes were observed for women compared to men in the felt arousal scale and PAAS (negative affect and fatigue). Feeling scale and felt arousal scale data plotted in a circumplex model of affect indicated a transition to high-activation and unpleasant-affect only for the women. There was good reliability between results from sessions 1 and 2. Conclusions Training to concentric failure resulted in negative changes in affective perceptual responses only for women. This type of training should be used with caution since it may change the affect perception and reduce training adherence in women. Further studies are needed using larger sample sizes, different resistance-training exercises, and diverse training methods.

Cessation of resistance training could result in loss of the gains acquired. Therefore, the aim of the current study was to verify the effect of 1-year of detraining following resistance training on body composition, functional capacity, handgrip strength, localized muscular endurance, and countermovement jump performance (CMJ) in older adults. Fifteen participants (4 women and 11 men; 65.5 ± 4.3 years) completed all the procedures over the experimental period. The participants were followed up during a 9-week resistance training program and after 1-year detraining. Measurements included body composition, handgrip strength, localized muscular endurance, stair ascent and descent, timed up-and-go, and CMJ. The resistance training resulted in improvements in skeletal muscle mass, stair ascent and descent, handgrip strength, localized muscular endurance, and CMJ variables. After the detraining period, significant reductions were observed in skeletal muscle mass (Δ = − 0.92 ± 0.58 kg) and CMJ height, velocity, and impulse (Δ = − 3.03 ± 1.83 cm, − 0.063 ± 0.042 m/s, − 6.34 ± 8.49 N·s, respectively) compared to the post-training period, returning to the baseline values. Conversely, stair ascent and descent, handgrip strength, and localized muscular endurance did not differ after the detraining period (p > 0.05). Retention of functional capacity, localized muscular endurance, and handgrip strength improvements were observed. However, skeletal muscle mass and CMJ variables decreased after the detraining period.

By using different series of linear mixed models we investigated the influence of muscle strength gains on functional capacity (FC) improvements in older adults following resistance training (RT). ...

Unusual eccentric exercise (EE) may affect muscle ability to produce rapid force. Previous study suggested that short-term mate tea (MT) consumption may enhance muscle strength recovery from EE, but MT benefits on the rate of torque development (RTD) are unknown. This study investigated the effect of MT on RTD and muscle damage and antioxidant defence biomarkers following EE. In a randomised, crossover design, 12 men drank either MT or water (control; CON) for 11 days. On the 8th day, 3 sets of 20 maximal isokinetic eccentric for elbow flexors with one arm were performed. RTD of the elbow flexor muscles at 0–50, 0–100, 50–100, 0–200, and 100–200 ms were assessed before and at 0, 24, 48, and 72 h after exercise. Blood samples were obtained before and at 24, 48, and 72 h after exercise and analysed for creatine kinase (CK), aldolase (ALD), total phenols, and reduced:oxidized glutathione (GSH:GSSG) ratio. RTD0–50 deficit after EE was independent of treatment. Compared with CON, MT improved RTD0–100 at 48 h (21%, P = 0.015) and 72 h (24%, P = 0.022); RTD0–200 at 48 h (18%, P = 0.034) and 72 h (21%, P = 0.029); RTD50–100 at 48 h (25%, P = 0.001) and 72 h (19%, P = 0.011); and RTD100–200 at 72 h (28%, P = 0.038). CK peaked (P = 0.012) in both trials at 72 h, and ALD was higher in MT than in CON before and at 24 h (P = 0.005 and P 50 ms by 2–3 days after EE. Furthermore, MT ameliorated circulating levels of muscle damage and antioxidant biomarkers irrespectively of exercise.

This study investigated the relationship between habitual nutritional intake and the responsiveness of elderly individuals to resistance training. Nineteen participants (66.0 ± 4.5 years) completed body composition (dual-energy X-ray absorptiometry), functional capacity (timed-up-and-go, stair ascent, and stair descent), and neuromuscular tests (5-repetition maximum and countermovement jump) before and after a 9-week resistance training intervention. Habitual nutritional intake was evaluated at the beginning, middle, and end of the intervention. Participants were also divided into two groups based on their protein intake (low protein group 1.2 g/kg). Total Kcaloric and protein intake explained ~ 21–44% of the functional capacity improvements, while total Kcaloric and carbohydrate intake explained ~ 21–27% of the change in lean mass. Participants with high protein intake showed greater percentage improvement for timed-up-and-go (− 10.7 ± 4.9% and 0.4 ± 7.4%) and stair ascent (− 11.4 ± 7.6% and − 3.2 ± 5.3%) versus those with lower protein intake. Nutritional intake influenced individual responsiveness to resistance training in the elderly. Older adults with higher Kcaloric, protein, and carbohydrate intake presented greater improvement in functional capacity and lean mass following resistance training.

This study aimed to verify the effect of a pace training session at an intensity corresponding to the kick frequency at the anaerobic threshold (KFAT) on the internal load response and motor response performance of the roundhouse kick. Twelve black belt taekwondo athletes underwent two evaluation sessions: (1) performed the progressive specific test for taekwondo (PSTT) to identify the heart rate deflection point (HRDP) and the KFAT; (2) performed three 2-min rounds with a 1-min interval. Heart rate (HR) throughout each round and motor response performance before and after sessions were measured. The Student's T-test or Wilcoxon test was used, and p < 0.05 was adopted. During round 1, a lower internal load was observed (167 ± 10 bpm) compared with HRDP (179 ± 8 bpm; p = 0.035). During rounds 2 (178 ± 10 bpm; p = 0.745) and 3 (179 ± 8 bpm; p = 1), no differences were observed for an internal load and HRDP. Motor response performance showed no differences. However, a potentiation in the post countermovement jump test compared with rounds 1 (p = 0.012) and 2 (p = 0.028) was observed. The internal load (HR) observed at the intensity corresponding to KFAT can be considered in the prescription of training when the aim is to control the internal load responses without inducing fatigue.

Sant'Ana, J, Franchini, E, Murias, JM, and Diefenthaeler, F. Validity of a taekwondo-specific test to measure VO2peak and the heart rate deflection point. J Strength Cond Res 33(9): 2523-2529, 2019-This study investigated whether the progressive specific taekwondo test (PSTT) is a valid test to measure peak oxygen consumption (VO2peak) and the heart rate deflection point (HRDP) in taekwondo athletes. Eighteen male black belt athletes (25.3 ± 4.8 years; 8.2 ± 4.7 years of practice; 171.8 ± 4.7 cm; 76.1 ± 8.2 kg, and 13.1 ± 2.9% body fat) involved in regional- and national-level competitions performed the PSTT and an incremental treadmill test (IT). The following variables were analyzed: VO2peak, respiratory quotient, oxygen consumption at the HRDP (VO2HRDP), peak heart rate (HRpeak), HRDP, and peak posttest blood lactate concentration. During the PSTT, the peak kick frequency (FKpeak) and kick frequency at the HRDP (FKHRDP) were also obtained. During the IT, the peak speed and the speed at the HRDP were identified by the Dmax method (the first and last points of the curve were connected by a straight line, and the most distant point of the curve to the line was considered as the HRDP). No differences were observed between VO2 responses during the PSTT and IT (p > 0.05). VO2peak and VO2HRDP presented bias (1.3 ml·kg·min and -0.78 ml·kg·min, respectively) derived from the Bland and Altman plots, with the 95% limits of agreement indicating that the differences between the 2 measures can reach 11% for VO2peak and 17% for VO2HRDP. The PSTT is a valid tool to assess aerobic power and capacity in taekwondo athletes based on direct comparisons to a treadmill test. The test presents more specific variables for the assessment and training of taekwondo athletes, such as FKpeak and FKHRDP, which can be used to determine and control the effects of training and help coaches in prescribing training programs.

Although hip muscles are related to activities of daily living (ADLs) in older adults, there is a lack of evidence concerning the extensor–flexor hip torque–angle. A shift of the torque–angle relationship is caused by the aging process (increasing or reducing the range of motion) affecting the force production in a given muscular length during ADLs. Thus, the relationship between hip extensor–flexor muscles' force production and their association with functional capacity tests in elderly women were evaluated. Seventeen elderly women performed timed up and go, timed up and down stairs, and 30-s chair stand tests. Hip extensor–flexor isometric peak torques at 15°, 60°, 90°, and 100° (0° = full extension) were also assessed. Hip flexors produced the highest absolute and relative peak torque at a 15° angle and hip extensor muscles at 100°. A large and significant correlation (r = 0.62, p = 0.008) was observed only between absolute hip extensor peak torque at 90° and the 30-s chair stand test. When peak torque was normalized by body mass, the hip extensor–flexor muscles' peak torque obtained at all measured angles presented significant correlation with the 30-s chair stand test. The results indicate that for older women there is an optimum torque–angle for the hip flexor and extensor muscles. Furthermore, although the hip torque–angle relationship was measured under isometric contractions, there was a correlation with the 30-s chair stand test, which could indicate the presence of the isometric component during this movement.

The purpose of the present study was to investigate the volume-dependence of upper-body strength performance improvement and the retention effects after detraining in aging adults. Eighteen healthy, untrained, middle-aged volunteers were randomized into two groups: low volume (LV), mean = 494 kg. and high volume (HV), mean = 686 kg. load. Participants were tested and retested before a 12-week (2 times/week) period of RT for baseline values (pre-); after 6 weeks (middle) and 12 weeks of training (post-), and 12 weeks after interruption (detraining - no systematic exercise). On each test day, a five-repetition maximum (5-RM) for the seated row; handgrip strength test (HGS); and local muscular endurance for elbow flexors (LME) were carried out. Participants performed seated row training 2 times per week with a rest interval of at least 48 h between sessions. After 24 sessions of RT (resistance training), LME significantly increased in both groups (p 0.05), without differences between groups (14 vs. 18%, for LV and HV, respectively). In addition, 5-RM increased in both the LV (22%) and HV (20%) groups. There were no significant increases in HGS in either group (LV 3% and HV 6%). After detraining, both groups lost up to 15% of LME and 5-RM. In untrained, middle-aged adults, there is an increase in maximal dynamic strength and local muscular endurance, independent of volume chosen. Furthermore, after 12 weeks detraining, the loss does not decrease to baseline values.

The worldwide trajectory of increasing obesity rates is a major health problem precipitating a rise in the prevalence of a variety of co-morbidities and chronic diseases. Tendinopathy, in weight and non-weight bearing tendons, in individuals with overweight or obesity has been linked to metabolic dysfunction resulting from obesity. Exercise and dietary fibre supplementation (DFS) are common countermeasures to combat obesity and therefore it seems reasonable to assume that they might protect tendons from structural and mechanical damage in a diet-induced obesity (DIO) model. The purpose of this study was to determine the effects of a DIO, DIO combined with moderate exercise, DIO combined with DFS (prebiotic oligofructose), and DIO combined with moderate exercise and DFS on the mechanical and biochemical properties of the rat tail tendon. Twenty-four male Sprague-Dawley rats, fed a high-fat/high-sucrose diet were randomized into a sedentary, a moderate exercise, a DFS, or a moderate exercise combined with DFS group for 12 weeks. Additionally, six lean age-matched animals were included as a sedentary control group. DIO in combination with exercise alone and with exercise and DFS reduced the Young’s Modulus but not the collagen content of the rat tail tendons compared to lean control animals. However, no differences in the mechanical and biochemical properties of the rat tail tendon were detected between the DIO and the lean control group, suggesting that DIO by itself did not impact the tail tendon. It seems that longer DIO exposure periods may be needed to develop overt differences in our DIO model.

This study investigated the effect of 12 weeks of mat Pilates intervention (60 min sessions, three times per week) on lower limb rate of force development (RFD) parameters (absolute and relative values and contractile impulse) in physically active and overweight elderly women. Fourteen elderly women (age 62 ± 3 years) participated in this study. Workouts were performed in three sets; repetitions increased every 4 weeks, and exercise difficulty increased from beginner to intermediate and advanced levels. Knee extensor and hip extensor–flexor RTD parameters were measured at different time intervals (0–30, 0–50, 0–100, 0–150, 0–200, and 0–250 ms) before (weeks − 4 and 0, control period) and after 6 and 12 weeks of mat Pilates intervention. No statistical difference (p > 0.05) was observed between weeks − 4 and 0 (control period). However, significant increments were observed after week 12 for most time intervals for absolute and relative knee extensor and hip extensor–flexor RFD, as well as for contractile impulse for the same muscle groups. We conclude that the mat Pilates causes significant increments in knee extensor and hip extensor–flexor RFD and contractile impulse using an incremental structure of training in physically active elderly women.

This study aimed to analyse unilateral countermovement jumps (CMJ) performance and muscle soreness in lower limbs, as well as to compare lower limb asymmetry over 48h after a stretch-shortening cycle (SSC) fatigue protocol. Fourteen judo athletes performed unilateral CMJ on each leg before, and after the 5

Purpose Given the increasing research interest in ultrasound plantar aponeurosis (PA) thickness measurements, this study aimed to analyze the inter and intra-rater reliability of independent sonograms and to identify the error related to the image analysis procedure. Methods Twenty-one healthy men participated in this study. Imaging of PA consisted of two independent sonograms per subject. Two raters (R1 and R2) evaluated each sonogram twice using standardized steps. Precision of the image analysis procedure was analyzed using the Bland and Altman plot and Intraclass Correlation Coefficient (ICC). Agreement estimates and ICC were used to assess absolute and relative inter and intra-rater reliability. Results Reliability of PA thickness was found to depend strongly on the number of images acquired per subject. Intra-rater agreement for single measurements were 0.696 (R1) and 0.495 (R2), whereas average measurements yielded values of 0.821 (R1) and 0.662 (R2), respectively. Precision within a sonogram varied from ICC values of 0.873 to 0.960 (intra-rater) and 0.670 to 0.822 (inter-rater). Conclusion Most part of the error in PA thickness measurements seems to be related to the sonogram acquisition process and not to the visual inspection of the image. To minimize error, average values of a minimum of two images per subject should be used. The moderate agreement between raters found in this study ratifies the need of all measurements being made by the same rater or group of raters. If a single rater evaluates all subjects, performing multiple measurements over one image does not seem to affect ICC as much as acquiring multiple images.

Rossato, M, Dellagrana, RA, Sakugawa, RL, Lazzari, CD, Baroni, BM, and Diefenthaeler, F. Time response of photobiomodulation therapy on muscular fatigue in humans. J Strength Cond Res 32(11): 3285-3293, 2018-The aim of this study was to identify the effects of 2 different time responses on fatigue of knee extensor. Sixteen male volunteers (26 ± 6.0 years, 81 ± 12 kg, and 181 ± 7.4 cm) participated in the study. Participants performed the same protocol in 5 sessions {control, placebo (placebo applied both 6 hours before and immediately before the test), 6 hours before + immediately before (photobiomodulation therapy [PBMT] applied both 6 hours before and immediately before the test), 6 hours before (PBMT applied 6 hours before and placebo applied immediately before the test), and immediately before (placebo applied 6 hours before and PBMT applied immediately before the test)}. Photobiomodulation therapy was applied on knee extensor (9 sites; 30 J per site). Maximal isometric voluntary contraction (MIVC) was assessed before and after an isokinetic fatigue (45 flexion-extension concentric at 180°·s), associated with electromyography (root mean square [RMS] and median of frequency [MF]). For MIVC, there was no treatment × time interaction for all variables. Time effect was observed for peak torque (PT), RMS, and MF. Treatment effect was verified for PT, and 6 hours before + immediately before condition presented higher PT during MIVCpre than control (p = 0.004) and placebo (p = 0.044). The immediately before presented higher PT values than control (p = 0.047). Regarding MIVCpost, the PT for 6 hours before + immediately before presented higher values than control (p = 0.001) and placebo (p = 0.004). Peak torque during MIVC (pre to post) was reduced in 6 hours before + immediately before treatment (26%) compared with control (33%), placebo (29%), and immediately before (32%). The application of PBMT 6 hours + immediately before and immediately before exercise protocol is able to reduce the fatigue.

Ageing leads to substantial force production capacity reductions, which is an indicator of frailty and disability, and a mortality predictor in elders. Understanding the age-dependent neuromuscular mechanisms underlying force reductions can optimize healthcare professionals' exercise protocol choices for patients and allows researchers to investigate new interventions to mitigate these reductions. Our primary goal was to provide an updated review about the main neural and musculotendinous mechanisms underpinning age-related reductions in force capacity. Our secondary goal was to summarize how aerobic and strength training can lessen these age-related reductions. This review suggests that several steps in the force production pathway, from cortical to muscular mechanisms, are negatively affected by ageing. However, combining aerobic and strength training can attenuate these effects. Strength training (i.e. moderate to high- intensity, progressive volume, accentuated eccentric loading and fast concentric contraction velocity) can increase overall force production capacity by producing beneficial neural and musculotendinous adaptations. Additionally, aerobic training (i.e. moderate and high intensities) plays an essential role in preserving the structure and function of the neuromuscular system.

Progressive specific taekwondo test (PSTT) was designed to evaluate aerobic indicators and maximum frequency kick (FKMAX) in taekwondo athletes. Both can be used as specific aerobic power variables to estimate maximum oxygen uptake (VO2MAX). To determine a linear regression equation to estimate the VO2MAX during PSTT in taekwondo athletes. Twenty-two taekwondo athletes performed a PSTT. Oxygen consumption was measured and the equations to estimate VO2MAX were established by multiple linear regression. Regression coefficient (R), coefficient of determination (R2), and standard error of estimate (SEE) were stablished and p

Photobiomodulation therapy (PBMT) applied prior to exercise may provide ergogenic effects by delaying the onset of fatigue. The Brazilian jiu-jitsu (BJJ) is a domain combat sport in which elbow flexors’ isometric contraction is commonly performed. This study was aimed at investigating the effects of PBMT on torque parameters in groups of BJJ athletes (n = 10) and physically active men (n = 10). The strength testing protocol was composed of elbow flexors’ maximal isometric voluntary contractions at 90°; treatment application (placebo or PBMT); fatigue protocol; and one elbow flexors’ maximal isometric voluntary contraction. Magnitude-based inference analyses were used to examine practical significance. BJJ athletes presented higher relative isometric peak torque values pre (ES = 0.92) and post (ES = 1.32) fatigue protocol than those observed in physically active men. Beneficial results were shown in the time to exhaustion (difference: 5.5 s, likely beneficial) and impulse during fatigue test (difference 271.1 N m s, possibly beneficial) for physically active men and in the impulse for BJJ athletes (difference 179.0 N m s, possibly beneficial) in favor of PBMT compared to placebo. The PBMT was efficient in delaying the onset of fatigue regardless of the individuals’ training level and could be suggested as an ergogenic factor to improve muscle performance.

The aims of this pilot study were to verify which muscle strength tests better explain bone mineral content (BMC) of the femoral neck and lumbar spine and to develop predictive equations to estimate femoral neck and lumbar spine BMC. Twenty-nine subjects aged 56–76 years old (12 women and 17 men) participated in the study. Femoral neck and lumbar spine BMC was evaluated by Dual X-ray absorptiometry (DXA). Muscle strength measurements included maximal isometric voluntary contractions of knee extensors and flexors, vertical jump, 5-repetition maximum of the leg press (5-RM LP ) and seated leg curl (5-RM LC ), and handgrip strength. Women presented a moderate to strong correlation between femoral neck BMC and 5-RM LP (r = 0.819), 5-RM LC (r = 0.879), knee extensors peak torque (r = 0.699), and handgrip strength (r = 0.663), as well as between lumbar spine BMC and the 5-RM LP test (r = 0.845) and manual grip strength (r = 0.699). For females, the 5-RM LP and 5-RM LC tests most fully explained femoral neck BMC (R 2 = 0.859) and the 5-RM LP test and body mass explained lumbar spine density (R 2 = 0.757) for females. Men did not present correlations between BMC and strength variables. For females, the 5-RM LP and 5-RM LC variables explained the variations of femoral neck BMC, while 5-RM LP and body mass explained lumbar spine BMC. Future studies should evaluate a larger sample size and prioritize the strength tests with a greater predictive capacity.

Purpose:To compare the oxygen-uptake () kinetics during skating on a treadmill and skating on a slide board and to discuss potential mechanisms that might control thekinetics responses during skating.Methods:Breath-by-breath pulmonaryand near-infrared spectroscopy–derived muscle deoxygenated hemoglobin and myoglobin ([HHbMb]) were monitored continuously in 12 well-trained, young, long-track speed skaters. On-transientand [HHbMb] responses to skating on a treadmill and skating on a slide board at 80% of the estimated gas exchange threshold were fitted as monoexponential function. The signals were time-aligned, and the individual [HHbMb]-to-ratio was calculated as the average value from 20 to 120 s after exercise starts.Results:The time constants for the adjustment of phase II(τ) and [HHbMb] (τ [HHbMb]) were low and similar between slide board and treadmill skating (18.1 [3.4] vs 18.9 [3.6] for τand 12.6 [4.0] vs 12.4 [4.0] s for τ [HHbMb]). Theratio was not different from 1.0 (P > .05) in both conditions.Conclusions:The fastkinetics during skating suggest that chronic adaptation to skating might overcome any possible restriction in leg blood flow during low-intensity exercise. Theratio values also suggest a good matching of O2delivery to O2utilization in trained speed skaters. The similar τand τ [HHbMb] values between slide board and treadmill further reinforce the validity of using a slide board for skating testing and training purposes.

Objective High-intensity intermittent exercise (HIIE) may enhance the antiinflammatory status. The jucara fruit juice (JFJ) has well-established antioxidant and antiinflammatory properties. This study investigated the effect of JFJ consumption on the inflammatory response to HIIE in physically active subjects. Methods In a randomized crossover design, 15 men were assigned to drink 250 mL of either JFJ or water (control) 1 h before a cycling HIIE session (seven sets of 60 s at 100% peak power output; 75 s recovery between sets). Blood samples were obtained before and at 0, 30, and 60 min post-HIIE, and the serum was analyzed for interleukin (IL)-6, IL-1β, IL-8, IL-10, tumor necrosis factor–α, and cortisol. Results After HIIE, the IL-6 levels were higher than baseline (percent change) at 30 min (P = 0.041) and 60 min (P = 0.038) for the control, but were unaffected by JFJ. IL-10 was higher in the JFJ group than in the control at 30 min (d = ‒0.63). Tumor necrosis factor–α was lower than baseline at 30 min for the control (d = ‒0.71) and at 60 min for the JFJ group (d = ‒0.60). For control, cortisol increased to higher than the baseline at 30 and 60 min (d = 0.54 and d = 0.76, respectively). For the JFJ group, the cortisol levels were significantly higher than the baseline at 30 min (P = 0.022). Performance during sprints was higher in the JFJ group than in the control (P = 0.002). In the control group, performance was with both IL-6 (semipartial correlation; sr = −0.59, large effect size) and cortisol at 0 h (sr = −0.52, large effect size). Conclusions JFJ intake attenuated the antiinflammatory response to HIIE, possibly resulting from a lower degree of muscle stress.

Purpose: To investigate the criterion validity of a maximal incremental skating test performed on a slide board (SB). Methods: Twelve subelite speed skaters performed a maximal skating test on a treadmill and on a SB. Gas exchange threshold (GET), respiratory compensation point (RCP), and maximal variables were determined. Results: Oxygen uptake () (31.0 ± 3.2 and 31.4 ± 4.1 mL·min−1·kg−1), percentage of maximal () (66.3 ± 4 and 67.7 ± 7.1%), HR (153 ± 14 and 150 ±12 bpm), and ventilation (59.8 ± 11.8 and 57.0 ± 10.7 L·min−1) at GET, and (42.5 ± 4.4 and 42.9 ± 4.8 mL·min−1·kg−1), percentage of (91.1 ± 3.3 and 92.4 ± 2.1%), heart rate (HR) (178 ± 9 and 178 ± 6 bpm), and ventilation (96.5 ± 19.2 and 92.1 ± 12.7 L·min−1) at RCP were not different between skating on a treadmill and on a SB. (46.7 ± 4.4 vs 46.4 ±6.1 mL·min−1·kg−1) and maximal HR (195 ± 6 vs 196 ± 10 bpm) were not significantly different and correlated (r = .80 and r = .87, respectively; P at GET, RCP, and obtained on a SB were correlated (r > .8) with athletes’ best times on 1500 m. Conclusions: The incremental skating test on a SB was capable to distinguish maximal ( and HR) and submaximal (, % , HR, and ventilation) parameters known to determine endurance performance. Therefore, the SB test can be considered as a specific and practical alternative to evaluate speed skaters.

Reproducibility of frequency content from surface electromyography (sEMG) signals has not been assessed and it is unknown if incremental load testing design could affect sEMG in cycling. The goals of this study were to assess the reproducibility of measures from sEMG frequency content between sessions and to compare these frequency components between a ramp and a step incremental cycling test. Eighteen cyclists performed four incremental load cycling tests to exhaustion. Two tests were performed using a step increment (load started at 100 W for 3 min followed by increments of 30 W every 3 min) and two were performed using a ramp increment (load started at 100 W for 1 min followed by increments of 30 W·min−1). sEMG was monitored bilaterally for the rectus femoris and vastus lateralis throughout the tests and converted into overall activation (whole signal bandwidth), high- and low-frequency contents. The reproducibility of the frequency content ranged from none to strong (ICC = 0.07–0.90). Vastus l...

— The present study aimed to compare the power, anaerobic capacity (AC) and performance in a road bicycle race among cyclists with and without risk of disordered eating behaviors (DEB). The sample was selected in a non-probabilistic way, totaling 69 male road cyclists aged between 19 and 30 years. The Wingate test was used to evaluate peak power (PP) and mean power. Time in minutes was adopted to determine performance in a 120-km road cycling race (competitive event). The Eating Attitudes Test (EAT-26) was completed to assess DEBs. The results did not indicate a difference in PP among cyclists with and without risk of DEBs ( F (2, 67) =3.92; p =0.13). Findings showed a difference in mean power among cyclists with and without risk of DEBs ( F (2, 67) =36.43; p =0.01). The results revealed a difference in performance in 120-km cycling races among cyclists with and without risk of DEBs ( F (2, 67) =46.03; p =0.01). It could be concluded that DEBs were associated with a lower mean power and performance in a competitive event among male road cyclists, although the same was not true for PP.Keywords: exercise; metabolism; performance; stress.

This study investigated how the combination of workload and fatigue affected the frequency components of muscle activation and possible recruitment priority of motor units during skating to exhaustion. Ten male competitive speed skaters performed an incremental maximal test on a slide board. Activation of six muscles from the right leg was recorded throughout the test. A time-frequency analysis was performed to compute overall, high, and low frequency bands from the whole signal at 10, 40, 70, and 90% of total test time. Overall activation increased for all muscles throughout the test (p 0.05 and ES 0.80). There was an increase in low frequency (90 vs. 10%, p = 0.035, ES = 1.06) and a decrease in high frequency (90 vs. 10%, p = 0.009, ES = 1.38, and 90 vs. 40%, p = 0.025, ES = 1.12) components of gluteus maximus. Strong correlations were found between the maximal cadence and vastus lateralis, gluteus maximus and gluteus medius activation at the end of the test. In conclusion, the incremental skating test lead to an increase in activation of lower limb muscles, but only gluteus maximus was sensitive to changes in frequency components, probably caused by a pronounced fatigue.

RESUMO O objetivo foi analisar o perfil das teses e seus artigos em relação às áreas de concentração do PPGEF/UFSC. Analisaram-se 103 teses e 196 artigos (2009-2019), das áreas: Biodinâmica do Desempenho Humano (BDH), Teoria e Prática Pedagógica (TPP) e Atividade Física e Saúde (AFS). Dentre as teses defendidas, predominaram as temáticas relacionadas às suas próprias áreas de concentração, pesquisas quantitativas, de campo, de levantamento e experimentais. Referente aos artigos, verificou-se maior publicação em periódicos de estrato A do WebQualis/CAPES e com fator de impacto especialmente na BDH e AFS. Conclui-se que o PPGEF/UFSC tem gerado conhecimento satisfatório e diversificado nas três áreas, com crescente defesa de teses e produção de artigos de qualidade.

Background The current literature indicates that functional capacity is associated with physical performance and body composition measurements in older adults. However, it is not clear which tests can best explain the functional capacity in this population. This study aimed to investigate the physical performance and body composition determinants of functional capacity in older adults. Method Twenty-four older adults (66.4 ± 4.7y) undertook body composition (body fat and muscle), rate of torque development (0–50 and 0–200 ms); countermovement jump (height, power and impulse); leg-press and seated-leg-curl 5-repetition maximum; and functional-performance tests (Timed-up-and-go, stair ascent and stair descent). Findings Timed-up-and-go correlated with countermovement jump (height, R2 = 0.303; power, R2 = 0.198; and impulse, R2 = 0.224) and 5-repetition maximum (seated-leg-curl, R2 = 0.172). Stair ascent correlated with body fat (R2 = 0.213), rate of torque development (0–50 ms/body fat, R2 = 0.301; 0–200 ms, R2 = 0.197; 0–200 ms/body fat, R2 = 0.340), countermovement jump (height, R2 = 0.325; power/body fat, R2 = 0.413; impulse/body fat, R2 = 0.422) and 5-repetiton maximum (leg-press/body fat, R2 = 0.384; seated-leg-curl/body fat, R2 = 0.341). Stair descent correlated with rate of torque development (0–50 ms/body fat, R2 = 0.164; 0–200 ms, R2 = 0.203; 0–200 ms/body fat, R2 = 0.213), countermovement jump (height, R2 = 0.458; power, R2 = 0.212; power/body fat, R2 = 0.358; impulse, R2 = 0.218; impulse/body fat, R2 = 0.369) and 5-repetition maximum (leg-press/body fat, R2 = -0.227; seated-leg-curl/body fat, R2 = 0.209; seated-leg-curl, R2 = 0.181). Interpretation Higher body fat is associated with weaker stair ascent performance. An increase in the correlation coefficient was observed for the countermovement jump, rate of torque development, and 5-repetition maximum tests when normalized by body fat compared to the absolute values. Countermovement jump height presented the highest correlation to timed-up-and-go and stair descent, while impulse/body fat for stair ascent.

The purpose of this study was to assess whether dry needling (DN) added to photobiomodulation (PBM) has effects on the treatment of active myofascial trigger points in the upper trapezius.This study was a randomized clinical trial, with 43 participants divided into 3 groups: DN and PBM (DNP), DN, and DN outside of the trigger point (DNout). Each group received 1 session of DN followed by PBM therapy with the machine turned on or off. Pain, disability, pain pressure threshold, and muscle activity were assessed before the intervention and afterward at intervals of 10 minutes, 30 minutes, 1 week, and 1 month.Pain decreased after intervention in the DNP and DNout groups, with mean differences, respectively, of 1.33 cm (95% confidence interval [CI], 0.019-2.647) and 2.78 cm (95% CI, 1.170-2.973). Scores for the disability questionnaire decreased in all groups after intervention (F = 36.53, P.0001) after the intervention, with mean differences of 3.8 points in the DNP group (95% CI, 1.082-5.518), 3.57 in the DN group (95% CI, 0.994-6.149), and 5.43 in the DNout group (95% CI, 3.101-7.756). There were no significant differences between or within groups in pain pressure threshold (F = 2.14, P = .139), with mean differences after 30 minutes of 0.139 kgf for the DNP group (95% CI, -0.343 to 0.622), 0.273 for the DN group (95% CI, -0.661 to 1.209), and -0.07 for the DNout group (95% CI, -0.465 to 0.324). Muscle activation for the DN group increased 8.49% after the intervention, where for the DNP group it decreased 11.5%, with a significant difference between groups.DN added to PBM presented similar results compared to DNout and DN. In this sample, the effects of the application of DN outside of the trigger point had better effects on pain and disability scores than DN applied directly on the trigger point.

The performance of Brazilian jiu-jitsu (BJJ) fighters is dependent on rapid and maximal elbow strength actions. Appropriate strength balance between elbow flexors (F) and extensors (E) across the full joint range of motion may be required to decrease risk of injuries.To compare rapid and maximal elbow F/E strength balance through full range of motion in BJJ fighters.Twenty-three male BJJ fighters (27.9 ± 4.6 years, 82.9 ± 10.9 kg, 174.5 ± 6.8 cm, and 15.3 ± 6.8% body fat) with 8.2 ± 6.5 years of practice volunteered to participate. Participants were tested for rate of torque development (RTD) and peak torque (PT) of elbow F and E at six angles (45°, 60°, 75°, 90°, 105°, and 120°; 0° = full extension). Rapid (F RTD/E RTD) and maximal (F PT/E PT) angle-specific torque (AST) ratios were calculated.Rapid AST ratio at 45° (0.66 ± 0.18) and maximal AST ratio at 45° (0.91 ± 0.16) and 120° (0.88 ± 0.20) were significantly less than all other AST ratios at mid-point angles of elbow range of motion (p 0.05). Individual data demonstrates that both beginners and advanced BJJ fighters present overall similar rapid and maximal F/E AST imbalances.BJJ fighters present greater rapid and maximal strength imbalances at extreme-compared to mid-point angles of range of motion. Results may benefit coaches to develop strength exercises focusing on these specific angles to potentially reduce the risk of elbow injury and improve performance of BJJ fighters.

This study aimed to assess the validity of the first (EMGth1) and second (EMGth2) breakpoints in the EMG signal during skating.Ten well-trained long track speed skaters performed a maximal incremental skating test on a slide board. EMG signals from six lower limb muscles were recorded during the last 15 s of each stage and converted to Root Mean Square for determination EMGth1 and EMGth2 using mathematical (2 and 3 linear regressions) and visual methods.EMGth1 had a low detection rate (50%) while EMGth2 could be identified visually in 80% of cases, in 85% of cases using 2-lines and 63% using 3-lines regression. Quads (VL + VM) and Gluts (GM + GMd) had the highest EMGth2 detection rate for all methods (70%). EMGth2 from Quads and Gluts detected by the 2-lines and 3-lines regression were not different than the second ventilatory threshold (VT2) (p 0.05), while the visual method overestimated VT2 (p 0.01). EMGth2 detected from Quads by the 2-lines regression method presented better correlation with VT2 stage (r = 0.91), lowest bias, and limit of agreement. We conclude that EMG is a valid non-invasive method to detect VT2 during skating when using a mathematical method to determine EMGth2.

Cycling ergometer protocols are commonly integrated with a virtual reality environment (VRE), especially because of its static position that also allows multiple exercise experiments. Concerning VRE scenarios, visually delayed situations like the ones produced at excessive low update rates can also affect the sense of presence and physiological responses. However, the main interface between the subject and a cycling VRE is the power applied over the crank, and there are only a few experiments to evaluate the effect of delayed situations on this particular interface. Thus, this work aims to investigate the effects of the power update rate (PUR) over the subject`s performance on an avatar-based simulator during a drafting task. A custom cycling VRE was built, and 21 male recreational cyclists (175.9 ± 7.5 cm; 76.5 ± 13.9 kg) were tested at six different PUR levels from 100 to 3000 ms. As a result, PUR affects performance scores (virtual distance, efficiency, and heart rate

Rodrigues, R, Franke, RA, Teixeira, BC, Macedo, RCO, Diefenthaeler, F, Baroni, BM, and Vaz, MA. Can the combination of acute alcohol intake and one night of sleep deprivation affect neuromuscular performance in healthy male adults? A cross-over randomized controlled trial. J Strength Cond Res 33(5): 1244-1251, 2019-The aim of this work was to perform a cross-over study to compare isolated and combined effects of alcohol intake and sleep deprivation on neuromuscular responses. Ten young and physically active male subjects were allocated to 4 conditions: (a) placebo intake + normal sleep (PLA + SLE); (b) alcohol intake + normal sleep (ALC + SLE); (c) placebo intake + sleep deprivation (PLA + SDP); and (d) alcohol intake + sleep deprivation (ALC + SDP). In each condition, volunteers ingested 1 g of alcohol per kg of body mass of alcoholic beer or nonalcoholic beer (placebo), followed by one night of normal sleep or sleep deprivation. In the next morning, neuromuscular performance (knee extensor isometric and concentric peak torque and time to task failure during the endurance test) and muscle activation were assessed. No differences were observed in the neuromuscular performance. We observed a significant reduction in quadriceps activation during the knee extensor isometric test in ALC + SDP compared with PLA + SLE (-20.8%; p = 0.02; d = 0.56). Our results demonstrated that acute alcohol intake and one night of sleep deprivation reduced quadriceps muscle activation without impact on neuromuscular performance.

Upper-body dynamic and isometric maximum strength are essential components for success in Brazilian jiu-jitsu (BJJ). This study was aimed at analysing strength parameters in the elbow flexor and extensor muscles of BJJ practitioners. Participants (n = 28) performed maximum isometric contractions of elbow flexors and extensors to determine peak torque (PT), rate of force development (RFD), and the torque–angle (T–A) relationship at elbow angles of 45°, 60°, 75°, 90°, 105°, and 120°. Additionally, concentric and eccentric PTs were measured at 1.04 rad·s-1. Student t-test and ANOVA were performed using α = 0.05. Elbow flexors were stronger isometrically (P

Fatigue and muscle damage negatively affect performance in lower limb exercises involving the stretch-shortening cycle in judo athletes during competition and training sessions. Photobiomodulation therapy has emerged as an effective non-invasive strategy to attenuate fatigue and muscle damage when applied before different types of exercises. Our objective was to investigate the effects of photobiomodulation therapy on fatigue and muscle damage in judo athletes. Sixteen judo athletes participated in the study (23.1 ± 3.8 years, 77.9 ± 14.9 kg, 173.1 ± 8.9 cm, 17.5 ± 7.3 body fat%, 12.9 ± 5.0 years of practice). Each participant received, in a randomized manner, photobiomodulation in one limb and placebo in the contralateral limb on the same day. Thereafter, subjects performed a stretch-shortening cycle protocol to induce muscle fatigue and damage. Countermovement jump (impulse, peak power, peak velocity, and peak force), echo intensity (rectus femoris and vastus lateralis), and muscle soreness were assessed at different time points before, during, immediately post, and 24 and 48 h after the protocol. Muscle fatigue was detected due to reductions in countermovement jump impulse (14.7 ± 9.8 and 15.9 ± 15.5%), peak power (12.9 ± 8.5 and 11.9 ± 6.9%), peak velocity (8.6 ± 8.1 and 6.5 ± 6.0%), and peak force (7.0 ± 5.3 and 8.0 ± 6.1%) after the protocol (p < 0.001), for placebo and photobiomodulation therapy, respectively. Muscle damage was detected due to reductions in countermovement jump impulse (−6.1 ± 19.2% and −4.5 ± 9.2%, p < 0.05), increases in echo intensity (rectus femoris, 21.0 ± 11.9 and 20.8 ± 9.0%; and vastus lateralis, 22.4 ± 23.2%; and 16.7 ± 23.8%; p < 0.001), and quadriceps muscle soreness (3.6 ± 1.6 and 3.5 ± 1.7 a.u; p < 0.011), 48 h after the protocol, for placebo and photobiomodulation therapy, respectively. No differences were observed between photobiomodulation therapy and placebo at any time points for any variables (p > 0.05), indicating no positive effect favoring photobiomodulation therapy. In conclusion, our findings suggest no effect of photobiomodulation therapy applied before exercise to reduce lower limb muscle fatigue and damage during and following a stretch-shortening cycle protocol in judo athletes.

This study aimed to analyze neuromuscular and postural control in visually and nonvisually impaired judo athletes. Two judo athletes, one visually impaired and the other nonvisually impaired, participated in the study. The athletes presented similar demographic, anthropometric, and judo-technical characteristics. They performed maximal isometric handgrip strength (dominant and nondominant hand), vertical jumps (countermovement jump [CMJ] and squat jump [SJ]), and center of pressure assessment in three positions: neutral, anteroposterior, and judo combat base (Migi-shizentai). The main findings showed that the visually impaired athlete presented higher standing balance in the neutral and anteroposterior positions than non-visually impaired athlete (effect size [ES]>2.0). In the Migi-shizentai position, the disparity between both athletes was reduced, particularly in the displacement area (ES=0.52). The visually impaired athlete showed higher performance in the SJ but lesser performance in CMJ and handgrip strength tests than nonimpaired athlete (ES>2.0). We concluded that the postural stability was higher in the visually impaired athlete in the neutral and anteroposterior position, but similar to the nonvisually impaired athlete in Migi-shizentai position, possible due to the influence of judo practice. Moreover, the visually impaired athlete showed higher performance in the SJ than nonvisually impaired.

Saddle height influences cycling performance and would be expected to influence cyclists physically, perceptually, and emotionally. We investigated how different saddle positions and cadences might affect cyclists’ torque, heart rate, rate of perceived exertion (RPE), and affective responses (Feeling scale). Nine male recreational cyclists underwent cycling sessions on different days under different conditions with a constant load. On Day 1, the saddle was at the reference position (109% of the distance from the pubic symphysis to the ground), and on Days 2 and 3, the saddle was in the “upward position” (reference + 2.5%) and “downward position” (reference − 2.5%) in random order. Each session lasted 30 minutes and was divided into three cadence-varied 10-minute stages without interruption: (a) freely chosen cadence (FCC), (b) FCC − 20%, and (c) FCC + 20%. We assessed all dependent measures at the end of each 10 minute stage. While there was no significant interaction (Saddle × Cadence) for any of the analyzed variables, torque values were higher at lower cadences in all saddle configurations, and the FCC + 20% cadence was associated with faster heart rate, higher RPE, and lower affect compared with FCC and FCC − 20% in all saddle positions. At all cadences, the saddle at “downward position” generated a higher RPE compared with “reference position” and “upward position.” The affective response was lower in the “downward position” compared with the “reference position.” Thus, while cyclists perceived the downward (versus reference) saddle position as greater exercise effort, they also associated it with unpleasant affect.

Understanding the influence of strength training intensity on subsequent recovery in elderly is important to avoid reductions in physical function during the days following training. Twenty-two elderly were randomized in two groups: G70 (65.9 ± 4.8 years, n = 11) and G95 (66.9 ± 5.1, n = 11). Baseline tests included maximum voluntary isometric contraction (peak torque and rate of torque development - RTD), countermovement jump, and functional capacity (timed up and go, stairs ascent and descent). Then, both groups performed a single strength training session with intensities of 70% (G70) or 95% (G95) of five repetition maximum. The same tests were repeated immediately, 24 h, 48 h, and 72 h after the session. Peak torque was lower than baseline immediately after for both groups and at 24 h for G95. Compared with G70, G95 had lower peak torque at 24 h and 48 h. Countermovement jump, timed up and go, stairs ascent, and RTD at 0–50 ms only differed from baseline immediately after for both groups. RTD at 0–200 ms was lower than baseline immediately after and 24 h after the session for both groups. In conclusion, reduced physical function immediately after strength training can last for 1–2 days in elderly depending on the type of physical function and intensity of training. Higher intensity resulted in greater impairment. Exercise prescription in elderly should take this into account, e.g., by gradually increasing intensity during the first months of strength training. These results have relevance for elderly who have to be fit for work or other activities in the days following strength training.

While it is accepted that resistance training can improve functional capacity in older individuals, the neuromuscular source of this improvement has yet to be identified. This study investigated the link between improved neuromuscular performance and functional capacity after a 12-week resistance training period in untrained healthy older individuals. Fifteen older men and women (60–71 years) adhered to a 4-week control period, followed by 12 weeks of non-linear resistance training for the lower limbs. Maximum dynamic leg press strength (1-RM), maximum isometric knee extension torque and rate of torque development (RTD) were evaluated at − 4, 0, 4, 8, and 12 weeks, and muscle activity was assessed at 0, 4, 8, and 12 weeks. Functional capacity tests (chair rise, stair ascent and descent, and timed up and go) were performed at − 4, 0, and 12 weeks. No changes occurred during the control period, but the group increased their 1-RM strength (from 142 ± 53 to 198 ± 43 kg, p = 0.001), which was accompanied by an increase in vastus lateralis activation (p = 0.008) during the intervention. Increase was observed at all RTD time intervals at week 8 (p

The purpose of this study was to verify the photobiomodulation therapy (PBMT) effects with different doses on neuromuscular economy during submaximal running tests. Eighteen male recreational runners participate in a randomized, double-blind, and placebo-controlled trial, which each participant was submitted to the same testing protocol in five conditions: control, placebo, and PBMT with doses of 15, 30, and 60 J per site (14 sites in each lower limb). The submaximal running was performed at 8 and 9 km h−1 during 5 min for each velocity. Muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), and gastrocnemius lateralis (GL) was collected during the last minute of each running test. The root mean square (RMS) was normalized by maximal isometric voluntary contraction (MIVC) performed a priori in an isokinetic dynamometer. The RMS sum of all muscles (RMSLEG) was considered as main neuromuscular economy parameter. PBMT with doses of 15, 30, and 60 J per site [33 diodes = 5 lasers (850 nm), 12 LEDs (670 nm), 8 LEDs (880 nm), and 8 LEDs (950 nm)] or placebo applications occurred before running tests. For the statistical analysis, the effect size was calculated. Moreover, a qualitative inference was used to determine the magnitude of differences between groups. Peak torque and RMS during MIVCs showed small effect sizes. According to magnitude-based inference, PBMT with dose of 15 J per site showed possibly and likely beneficial effects on neuromuscular economy during running at 8 and 9 km h−1, respectively. On other hand, PBMT with doses of 30 and 60 J per site showed possible beneficial effects only during running at 9 km h−1. We concluded that PBMT improve neuromuscular economy and the best PBMT dose was 15 J per site (total dose of 420 J).

Lisboa, FD, Raimundo, JAG, Salvador, AF, Pereira, KL, Turnes, T, Diefenthaeler, F, Oliveira, MFMd, and Caputo, F. Acute cardiopulmonary, metabolic, and neuromuscular responses to severe-intensity intermittent exercises. J Strength Cond Res 33(2): 408-416, 2019-The purpose of this study was to compare cardiopulmonary, neuromuscular, and metabolic responses to severe-intensity intermittent exercises with variable or constant work rate (CWR). Eleven cyclists (28 ± 5 years; 74 ± 7 kg; 175 ± 5 cm; 63 ± 4 ml·kg·min) performed the following tests until exhaustion on separate days: (a) an incremental test; (b) in random order, 2 CWR tests at 95 and 110% of the peak power for the determination of critical power (CP); (c) 2-4 tests for the determination of the highest power that still permits the achievement of maximal oxygen uptake (PHIGH); and (d) 2 random severe-intensity intermittent exercises. The last 2 sessions consisted of a CWR exercise performed at PHIGH or a decreasing work rate (DWR) exercise from PHIGH until 105% of CP. Compared with CWR, DWR presented higher time to exhaustion (635 ± 223 vs. 274 ± 65 seconds), time spent above 95% of V[Combining Dot Above]O2max (t95% V[Combining Dot Above]O2max) (323 ± 227 vs. 98 ± 65 seconds), and O2 consumed (0.97 ± 0.41 vs. 0.41 ± 0.11 L). Electromyography amplitude (root mean square [RMS]) decreased for DWR but increased for CWR during each repetition. However, RMS and V[Combining Dot Above]O2 divided by power output (RMS/PO and V[Combining Dot Above]O2/PO ratio) increased in every repetition for both protocols, but to a higher extent and slope for DWR. These findings suggest that the higher RMS/PO and V[Combining Dot Above]O2/PO ratio in association with the longer exercise duration seemed to have been responsible for the higher t95% V[Combining Dot Above]O2max observed during severe DWR exercise.

Accuracy is essential to the validity of functional capacity measurements. To evaluate the error of measurement of functional capacity tests for elders and suggest the use of the technical error of measurement and credibility coefficient. Twenty elders (65.8 ± 4.5 years) completed six functional capacity tests that were simultaneously filmed and timed by four evaluators by means of a chronometer. A fifth evaluator timed the tests by analyzing the videos (reference data). The means of most evaluators for most tests were different from the reference (p

The aim of this study was to investigate whether 12 weeks of leg press strength training exercise could affect the conventional and functional hamstring:quadriceps ratios in the elderly. Twelve elderly participants were submitted to a 12 week progressive training protocol (two sessions/week) using a 45° leg press exercise. A significant increase in the one repetition maximum was observed after 4, 8, and 12 weeks (p = 0.001, p 0.001, and p 0.001, respectively) compared to week 0 and after 8 (p = 0.011) and 12 weeks (p = 0.001) compared to week 4. The concentric knee extensor peak torque was significantly higher at weeks 8 (p = 0.001) and 12 (p = 0.024) compared to week 0. There was no change in the concentric and eccentric knee flexor peak torques (p = 0.629 and 0.274, respectively) and conventional ratio (p 0.314) after 12 weeks of training. The functional ratio (eccentric knee flexor peak torque:concentric knee extensor peak torque) reduced significantly after 8 (p = 0.034) and 12 (p = 0.036) weeks of strength training. Although the 45° leg press exercise requires knee extensor and flexor, hip extensor, and plantar flexor muscle strength, our findings suggest that the isolated use of the 45° leg press exercise reduces the knee functional ratio after 8 weeks of training. Therefore, 45° leg press exercise alone, without a hamstring exercise, should not be recommended for elderly individuals.

Background TReaction is a mobile app developed to determine strike response time at low cost and with easy application in combat sports. However, the validity and accuracy of the response time obtained by the TReaction app has not yet been evaluated. Objective This study aimed to test the validity and reliability of the TReaction app in measuring motor response time in combat sports. Methods A total of two athletes performed 59 strikes to assess the response time upon visual stimulus using the TReaction app simultaneously with a high-speed camera. Accuracy of the measure was verified using a computer simulator programmed to discharge visual stimuli and obtain the response time. Pearson correlation, Student t test for dependent samples, and the Bland-Altman analysis were performed. Accuracy was verified using the intraclass correlation coefficient. Effect size (g) and the typical error of measurement (TEM) were calculated. The significance level was set at P Results No significant difference (P=.56) was found between both systems. The methods presented a very strong correlation (r=0.993). The magnitude of differences was trivial (g Conclusions Our findings suggest that the TReaction app is a valid tool to evaluate the response time in combat sports athletes.

This study aimed to analyze the anaerobic performance and muscle activation during a supramaximal cycling test at three different saddle positions. Twelve competitive cyclists completed an incremental cycling test and three 30-s Wingate tests in three different saddle heights (reference, downward, and upward), in a random order, on different days. The saddle height was individually shifted downward and upward (seeing 2.5% of the distance from the pubic symphysis to ground) from the reference position. The electromyographic signal (EMG) data was obtained from the rectus femoris, vastus lateralis, biceps femoris (long head), and gastrocnemius lateralis in order to assess muscle activation during the entire test. The anaerobic variables and the EMG data were divided into six consecutive windows of 5-s. The EMG signals were normalized by the first 5-s window of the reference position to provide the percentage changes throughout the test. The results suggest that during a 30-s Wingate test small changes in saddle height result in greater peak power output (reference=1380±241 W; downward=1497±175 W, p=0.036; upward=1491±225 W, p=0.049) and greater activation period for vastus lateralis (reference=33.6%, downward=33.2%, upward=35.0%; p=0.001) in comparision to rectus femoris (reference=24.5%, downward=25.2%, upward=23.7%), biceps femoris (reference=20.7%, downward=20.8%, upward=19.9%), and gastrocnemius lateralis (reference=21.2%, downward=20.8%, upward=19.9%). The results suggest that small adjustments in saddle height may affect the force-length relationship of the muscles of the lower limb, and consequently their recruitment pattern and their ability to generate force. RESUMO O presente estudo teve como objetivo analisar o desempenho anaeróbio e a ativação muscular durante um teste de ciclismo supramáximo em três diferentes alturas do selim. Doze ciclistas competitivos completaram um teste incremental em cicloergômetro e três testes de Wingate de 30 s em diferentes alturas do selim (referência, baixa e alta), de forma randomizada, em diferentes dias. A altura do selim foi alterada para baixo e para cima a partir da posição de referência usando como parâmetro o valor referente a (± 2,5%) da distância da sínfise púbica até o solo. O sinal eletromiográfico (EMG) foi obtido dos músculos reto femoral, vasto lateral, bíceps femoral (cabeça longa) e gastrocnêmio lateral. As variáveis anaeróbias e os dados de EMG foram divididos em seis janelas consecutivas de 5 s. Os sinals EMG foram normalizados pela primeira janela da posição de referência para estipular as mudanças percentuais ao longo do teste. Os resultados sugerem que durante o teste de Wingate de 30 s pequenas alterações na altura do selim resultam em aumento da potência pico (referência=1380±241 W; baixa=1497±175 W, p=0,036; alta=1491±225 W, p=0,049) e maior período de ativação percentual para o vasto lateral (referência=33,6%, baixa=33,2%, alta=35,0%; p=0,001) em relação ao reto femoral (referência=24,5%, baixa=25,2%, alta=23.7%), bíceps femoral (referência=20,7%, baixa=20,8%, alta=19,9%) e gastrocnêmio lateral (referência=21,2%, baixa=20,8%, alta=19,9%). Os resultados sugerem que pequenos ajustes na altura do selim podem afetar a relação força-comprimento e, consequentemente, a capacidade de gerar força e o padrão de recrutamento muscular dos membros inferiores.

Pedaling asymmetries quantified during stationary cycling, when cyclist body positioning and intensity remain unchanged, may not fully reproduce the training and competition situations, in which cyclists experience different intensities and may opt for different saddle positioning aiming at power output optimization. Previous studies showed that torque and power can be asymmetric in cyclists. It is not clear whether changes in saddle height and exercise intensity may affect asymmetries. The aim of the present study was to determine pedaling asymmetries during cycling at different saddle heights and different exercise intensities. Twelve competitive cyclists performed an incremental maximal test, a constant-load (“heavy” intensity domain), and a Wingate test. Constant load and the Wingate tests were repeated using three different saddle heights (reference and lower or higher by 2.5% of the distance from the pubic symphysis to the ground). Crank torque was recorded throughout the pedaling cycle. Asymmetry (higher torque for the preferred limb) was found in all saddle heights (p0.05) in both intensities. Our results suggest that asymmetric cyclists present a consistent pattern regardless of small changes in the saddle height or in exercise intensity. For practical implication, cyclists producing asymmetric torque may be adapted to this condition so they are continuously exposed to asymmetric effort and overload on the lower limbs. Resumo Assimetrias na pedalada quantificadas durante o ciclismo estacionário, em que a postura do ciclista e a intensidade não mudam significativamente, podem não reproduzir situações de treino e competições em que os ciclistas experimentam diferentes intensidades e optam por mudar a postura no selim para otimização da potência. Estudos prévios mostraram assimetrias no torque e potência de ciclistas. Não é claro se mudanças na posição do selim e intensidade afetam essas assimetrias. O objetivo do presente estudo foi determinar as assimetrias na pedalada durante o ciclismo em diferentes alturas de selim e diferentes intensidades de esforço. Doze ciclistas competitivos realizaram um teste incremental máximo, um teste de carga constante (domínio severo) e um teste de Wingate. Os testes de carga constante e Wingate foram repetidos usando três alturas de selim (referência e 2,5% abaixo ou acima da referência, que foi medida pela distância da sínfise púbica até o solo). O torque gerado no pedivela foi medido durante todo o ciclo de pedalada. Assimetrias (maior torque na perna preferida) foram encontradas em todas as alturas de selim (p

Reaction time and response time are considered important abilities and can potentially affect combat performance. This study investigated the effect of a specific fatigue protocol on reaction time, response time, performance time, and kick impact. Seven male athletes reported to the laboratory on two different days. During day one, athletes performed a specific progressive taekwondo test, and on day two, a protocol for determining reaction time, response time, performance time, and kick impact before and after a time to exhaustion test at an intensity level corresponding to the maximal kick frequency obtained during the specific progressive taekwondo test. Muscle activation from rectus femoris and kick impact of the preferred limb were assessed. No differences were observed for response time and performance time. However, kick impact decreased (43 ± 27 to 13 ± 10 g, p 0.01) while reaction time increased (145 ± 51 to 223 ± 133 ms, p 0.05). Moderate correlation was observed between kick impact and response time (r = 0.565; p 0.01), and kick impact and performance time (r = 0.494; p 0.05). Results indicate that coaches and athletes may use taekwondo training programmes on coordination-based exercises leading to improve response time and to reduce fatigue effects in order to improve technique effectiveness and enhance the possibilities of scoring in a competitive situation.

The aim of this study was to verify the agreement between body fat percentage (%BF) values evaluated by air displacement plethysmograph (ADP) and body adiposity index (BAI) in adults with Down’s syndrome (DS). Forty-five adults with DS volunteered to participate in this study (19 women; age 28.7±8.5 years and 26 men; age 29.1±8.8 years). The %BF was measured by ADP (%BFADP) and estimated by anthropometric measures [%BF=(hip circumference/height)1.5−18] (%BFBAI). Agreement between methods was evaluated by paired t-test, Pearson’s correlation coefficient and Bland–Altman analysis. Although high correlation coefficients were found between %BFADP and %BFBAI for women (r=0.78, P

Dietary phytochemical supplementation may improve muscle recovery from exercise. In this study, we investigated the effect of mate tea (MT) consumption – a phenol-rich beverage – on muscle strength and oxidative stress biomarkers after eccentric exercise. In a randomised, cross-over design, twelve men were assigned to drink either MT or water (control; CON) for 11 d. On the 8th day, subjects performed three sets of twenty maximal eccentric elbow flexion exercises. Maximal isometric elbow flexion force was measured before and at 0, 24, 48 and 72 h after exercise. Blood samples were obtained before and at 24, 48 and 72 h after exercise and analysed for total phenolics, GSH, GSSG, GSH:GSSG ratio and lipid hydroperoxides (LOOH). After eccentric exercise, muscle strength was significantly reduced over time, regardless of treatments. However, MT improved the rate of strength recovery by 8·6 % on the 1st day after exercise (PPPP