Detection of neuromechanical acute fatigue-related responses during a duathlon simulation: Is tensiomyography sensitive enough?

Author(s):  
Daniel Rojas-Valverde ◽  
Braulio Sánchez-Ureña ◽  
Carlos D Gómez-Carmona ◽  
Alexis Ugalde-Ramírez ◽  
Andrés Trejos-Montoya ◽  
...  

New technological advances are constantly being developed to assess fatigue and muscle damage in sports. Tensiomyography (TMG) has been used as an alternative method to indirectly assess these physiological responses. The aim of this study was to explore the potential use of TMG parameters (muscle radial deformation [Dm], time of contraction [Tc], delay time [Td], deformation rate until 10% [V10] and 90% [V90]) to detect neuromuscular acute fatigue-related responses during a duathlon compared to well-known biochemical (blood lactate [BLa]), perceptual (rate of perceived exertion [RPE]), and functional (jump performance [CMJ]) variables. Twenty-three well-trained athletes (age 33.6 ± 7.2 years, weight 64.4± 9.2 kg, height 1.7 ± 0.2 m, VO2max 56.7± 6.9 mL/kg/min, body fat 16.6 ± 8.4%, lean mass 53.2 ± 11.6 kg) performed a 5k-25k-5k duathlon under controlled indoor conditions at 23°C. TMG muscle properties (left and right gastrocnemius lateralis), BLa, RPE, and CMJ were measured pre-duathlon, during transition 1 (T1), during transition 2 (T2), and post-duathlon. After one-way analyses of variance, there were large differences in BLa ( p< 0.01), RPE ( p< 0.01) and CMJ ( p< 0.01). Large differences ( p< 0.01) were also found in Tc, Dm, Td, V10, and V90 as TMG muscle mechanical markers. Compared to well-known fatigue variables (CMJ, RPE, and BLa), Tc and Dm as TMG parameters measured in gastrocnemius lateralis seem to be sensitive enough to detect acute fatigue-related changes during duathlon. Differences reported in Td, V10, and V90 could be the result of muscle post-activation potentiation (PAP) after T1, and more evidence is needed for understanding this PAP phenomenon using TMG.

2005 ◽  
Vol 100 (2) ◽  
pp. 357-361 ◽  
Author(s):  
Meir Magal ◽  
Robert F. Zoeller

Ratings of perceived exertion (RPE) are used for exercise programming of cardiac rehabilitation patients, whenever it is difficult to use heart rate to set intensity due to medication or other factors. This investigation examined the physiological responses to two stepping exercise modes (upright and recumbent) at the same RPE. Analysis indicated significant physiological differences between the modes of exercise which may be mediated by postural differences. Specifically, the physiological responses to the recumbent exercise, but not the upright exercise, had the expected relationship with RPE, with recumbent stepping requiring less physiological effort than the upright stepping at the same RPE. As such, we cannot recommend with confidence that the prescription for upright exercise be made based on data from recumbent exercise or vice-versa.


2021 ◽  
Vol 78 (1) ◽  
pp. 209-217
Author(s):  
Bruna Costa ◽  
Danielly M. Ferreira ◽  
Petrus Gantois ◽  
Dalton de Lima-Júnior ◽  
Witalo Kassiano ◽  
...  

Abstract Performing repetitions to failure (RF) is a strategy that might acutely reduce neuromuscular performance, as well as increase the rating of perceived exertion (RPE) and the internal training load (ITL) during and after a resistance training (RT) session. Thus, this study aimed to analyze the acute effects of RF or repetitions not to failure (RNF) on countermovement jump (CMJ) performance and the ITL in trained male adults. Eleven men performed two experimental protocols in randomized order (RF vs. RNF). Under the RF condition, participants performed three sets of the leg extension exercise using 100% of the 10RM load and rest intervals of 180-s between sets. Under the RNF condition, participants were submitted to six sets of five repetitions with the same intensity and an 80-s rest interval between sets in the same exercise. The CMJ test was analyzed before and following (15-s and 30-min, respectively) each experimental session. The ITL was evaluated by multiplying the RPE and the total session time, 30-min after the protocol. No main effect or interaction time vs. condition was found for CMJ performance (p > 0.05). In contrast, the ITL showed higher values under the RF condition (p = 0.003). Therefore, even though RF-induced a greater ITL, our results suggest that adopting this strategy in one single-joint exercise for the lower limbs does not seem sufficient to reduce CMJ height.


Author(s):  
Hadi Nobari ◽  
Ana Ruivo Alves ◽  
Filipe Manuel Clemente ◽  
Jorge Pérez-Gómez

Abstract Background Digit ratio (2D:4D) characterized by the length of the second digit (2D) divided by the length of the fourth digit (4D), is a powerful marker of athletic performance. Some studies showed a negative correlation between 2D:4D ratio and sports performances. Objectives The purpose of the present study was three-fold: (1) to analyze the influence of anthropometric and 2D:4D ratio on variations of accumulated training load (ATL) and fitness parameters: maximal oxygen uptake (V̇O2max), countermovement jump (CMJ), isometric muscular strength of the knee extensor for hamstring (ISH) and flexor for quadriceps (ISQ) muscles; along three stages of evaluation of soccer players based on playing positions; (2) to analyze the correlations between 2D:4D ratio and aforementioned parameters; and (3) to investigate if variance in fitness levels and ATL can explain the 2D:4D ratio. Methods Twenty-four elite players under 17 years were daily monitored for their rating perceived exertion and ATL across 24 weeks over the season. Soccer players have also measured in three stages for anthropometric traits and fitness parameters. Results Significant differences were observed between playing positions for body mass, goalkeepers had higher body mass compared to centre-midfielder and winger players. Moreover, there were significant differences in ATL between early-season to mid-season in goalkeepers (P = 0.032). The 2D:4D ratio (left and right) shown largely and negatively association with muscular strength (ISQ: r =  − 0.80; r =  − 0.78, P ≤ 0.001, ISH: r =  − 0.63; r =  − 0.62, P = 0.001, respectively) and VO2max changes (r =  − 0.55, P = 0.005; r =  − 0.50, P = 0.013, respectively); lastly, both 2D:4D ratio significantly predicted changes in muscular strength and VO2max in young soccer players. Conclusions Goalkeepers tended to have higher body mass compared to centre-midfielder and winger players; and 2D:4D ratio revealed a mighty predictor of physical fitness changes in soccer players. Evidence should be helpful to professionals to highlight the usefulness of the 2D:4D into the identification of talent, but also to optimize young players' performance.


2012 ◽  
Vol 7 (4) ◽  
pp. 332-339 ◽  
Author(s):  
Jordan P.R. McIntyre ◽  
Grant A. Mawston ◽  
Simeon P. Cairns

Purpose:To quantify how whole-body power, muscle-function, and jump-performance measures change during prolonged cycling and recovery and determine whether there are relationships between the different fatigue measures.Methods:Ten competitive or recreationally active male cyclists underwent repeated 20-min stages of prolonged cycling at 70% VO2peak until exhaustion. Whole-body peak power output (PPO) was assessed using an all-out 30-s sprint 17 min into each cycle stage. Ratings of perceived exertion (RPE) were recorded throughout. Isometric and isokinetic muscle-function tests were made between cycle stages, over ~6 min, and during 30-min recovery. Drop-jump measures were tested at exhaustion and during recovery.Results:PPO initially increased or was maintained in some subjects but fell to 81% of maximum at exhaustion. RPE was near maximal (18.7) at exhaustion, with the time to exhaustion related to the rate of rise of RPE. PPO first started to decline only when RPE exceeded 16 (ie, hard). Peak isometric and concentric isokinetic torque (180°/s) for the quadriceps fell to 86% and 83% of pretest at exhaustion, respectively. In contrast, the peak concentric isokinetic torque (180°/s) of the hamstrings increased by 10% before declining to 93% of maximum. Jump height fell to 92% of pretest at exhaustion and was correlated with the decline in PPO (r = .79). Muscle-function and jump-performance measures did not recover over the 30-min postexercise rest period.Conclusions:At exhaustion, whole-body power, muscle-function, and jump-performance measures had all fallen by 7–19%. PPO and drop-jump decrements were linearly correlated and are appropriate measures of maximal performance.


Sports ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 94 ◽  
Author(s):  
Gabriel Sanders ◽  
Brian Boos ◽  
Frank Shipley ◽  
Corey Peacock

The purpose of the study was to assess glycogen content of the rectus femoris (RF) muscles utilizing high-frequency ultrasound throughout an intensive, nine-day preseason training period in NCAA division I volleyball athletes. In the morning prior to the beginning of practice, athletes (n = 13) left and right RF muscles were assessed via ultrasound to quantify muscle fuel ratings (0–100 score range). The recommended location of the RF ultrasound scans were based on manufacturer guidelines, and the same technician recorded the daily measurements. To assess daily training load, session ratings of perceived exertion (s-RPE) were utilized. A paired t-test revealed a large significant difference between left (51.7 ± 17.9) and right (32.8 ± 17.4) RF muscle fuel ratings (p < 0.001). There was also a major effect of time on s-RPE (p < 0.001) and left (dominant) RF fuel rating (p = 0.001). s-RPE decreased from the beginning to the end of the training camp. However, left RF fuel ratings increased from the first to the second day, then remained elevated all throughout the preseason. In conclusion, all athletes were left-leg dominant and had a 57.6% bilateral asymmetry between their left and right RF muscle fuel ratings despite changes in training load. High-frequency ultrasounds are a noninvasive assessment tool that can determine glycogen replenishment asymmetries in the RF.


Author(s):  
Andrea Crowell ◽  
Patricio Riva-Posse ◽  
Helen S. Mayberg

A growing circuit-based understanding of the mechanisms underlying psychological processes and psychiatric syndromes, paired with growing technological advances in neuroimaging and neuromodulation techniques, has led to the investigational use of deep brain stimulation as a surgical treatment for a variety of psychiatric disorders. Still in its early stages, there is reason for optimism about its potential use in patients with severe and treatment-refractory illness. However, as larger, randomized trials have not yet delivered on the promise of smaller, open-label case series, we must be cautious and attentive to appropriate patient selection and trial design in order to establish scientific efficacy and protect vulnerable populations.


2019 ◽  
Vol 67 (1) ◽  
pp. 235-245
Author(s):  
Javier Fernández-Rio ◽  
Luis Santos ◽  
Benjamín Fernández-García ◽  
Roberto Robles ◽  
Iván Casquero ◽  
...  

AbstractThe goal of this study was to assess the effects of a supervised slackline training program in a group of soccer players. Thirty-four male division I under-19 players (16.64 ± 0.81 years) agreed to participate in the study. They were randomly divided into an experimental group (EG) and a control group (CG). The first group (EG) followed a 6-week supervised slackline training program (3 sessions/week; 5-9 min/session), while the CG performed only regular soccer training. Several variables were assessed in all participants: acceleration (20-m sprint test), agility (90º turns test), jump performance (squat jump, countermovement jump), and postural control (Center of Pressure ( CoP) testing: length, area, speed, Xmean, Ymean, Xspeed, Yspeed, Xdeviation, Ydeviation). Ratings of perceived exertion and local muscle ratings of perceived exertions were also recorded after each slackline training session. At post-tests, there was a significant increase only in the EG in acceleration, agility, squat jump and countermovement jump performance, as well as several CoP variables: area in the bipedal support on a firm surface, and length, area and speed in the left leg on a firm surface. The program was rated as “somewhat hard” by the players, while quadriceps, gastrocnemius and tibialis anterior were the most exerted muscles while slacklining. In conclusion, slackline training can be an effective training tool for young, high-level soccer players.


2009 ◽  
Vol 4 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Craig A. Bridge ◽  
Michelle A. Jones ◽  
Barry Drust

Purpose:To investigate the physiological responses and perceived exertion during international Taekwondo competition.Methods:Eight male Taekwondo black belts (mean ± SD, age 22 ± 4 y, body mass 69.4 ± 13.4 kg, height 1.82 ± 0.10 m, competition experience 9 ± 5 y) took part in an international-level Taekwondo competition. Each combat included three 2-min rounds with 30 s of recovery between each round. Heart rate (HR) was recorded at 5-s intervals during each combat. Capillary blood lactate samples were taken from the fingertip 1 min before competition, directly after each round and 1 min after competition. Competitors’ rating of perceived exertion (RPE) was recorded for each round using Borg’s 6-to-20 scale.Results:HR (round 1: 175 ± 15 to round 3: 187 ± 8 beats·min−1; P < .05), percentage of HR maximum (round 1: 89 ± 8 to round 3: 96 ± 5% HRmax; P < .05), blood lactate (round 1: 7.5 ± 1.6 to round 3: 11.9 ± 2.1 mmol·L-1; P < .05) and RPE (round 1: 11 ± 2 to round 3: 14 ± 2; P < .05; mean ± SD) increased significantly across rounds.Conclusions:International-level Taekwondo competition elicited near-maximal cardiovascular responses, high blood lactate concentrations, and increases in competitors' RPE across combat. Training should therefore include exercise bouts that sufficiently stimulate both aerobic and anaerobic metabolism.


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