scholarly journals A simulated rugby match protocol induces physiological fatigue without decreased individual scrummaging performance

2017 ◽  
Vol 29 (1) ◽  
pp. 1-6 ◽  
Author(s):  
A Green ◽  
S Kerr ◽  
B Olivier ◽  
R Meiring ◽  
C Dafkin ◽  
...  

Background: A rugby union game consists of 80 minutes of strenuous exertion. Forwards are required to participate in the arduous activity of scrummaging throughout a game.Objectives: The purpose of this study was to identify whether rugby-match simulated fatigue modified individual scrummaging technique and reduced performance.Methods: Twelve forwards (body mass 106.2±13.3 kg; stature 179.5±8.4 cm) had individual scrum kinetics and kinematics assessed prior to and following a protocol that simulated a rugby match. The simulated rugby match protocol required participants to run at various velocities and perform rugby specific tasks. Rating of Perceived Exertion (RPE) was assessed using a 6-20 Borg scale and Visual Analogue Scale (VAS). Blood lactate, heart rate and RPE were measured prior to, at mid-point and after the simulated game, while markers of muscle damage (blood creatine kinase activity (CK) and urea) were measured prior to and following the protocol.Results: RPE (p<0.0001) and VAS (p<0.0001) showed significant increases between the pre- and post-simulation values. Of the physiological markers, heart rate (p<0.0001) and blood urea concentration (p=0.004) increased following the match simulation. No significant differences were observed for blood CK (p=0.281), individual scrummaging forces (p=0.433) or in the kinematic variables following the protocol. While physiological fatigue and subjective ratings of physiological fatigue may develop during a rugby simulation, no differences were observed in peak forces or in body kinematics at peak force.Conclusion: Physiological fatigue does not influence individual scrummaging performance and technique.

2016 ◽  
Vol 51 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Matthias Wilhelm Hoppe ◽  
Christian Baumgart ◽  
Thomas Hilberg ◽  
Jürgen Freiwald ◽  
Udo Frank Wehmeier

Abstract This study aimed to describe the acute changes of both standard physiological-perceptual markers and circulating microRNAs in response to tennis match-play in a detailed case report. Two elite male baseliners with comparable tennis experience were tested for anthropometric and fitness related variables and played 2 h of match-play on a red-clay court. The changes of standard physiological-perceptual markers including the heart rate, lactate concertation, creatine kinase activity, urea concentration and rating of perceived exertion as well as circulating microRNA-133a, -486 and -126 expression rates were examined at 10 different time-points (i.e., pre, during and up to 24 h post match-play). Player 2 had lower fitness related variables, but a higher heart rate, lactate concentration, creatine kinase activity and rating of perceived exertion during play than player 1. Player 2 showed an increase in all microRNAs (≤3.83-fold), most evident post match-play, whereas player 1 demonstrated a decrease (≤0.41-fold). The time-course in the changes of all standard physiological-perceptual markers was similar in both players, whereas this of the microRNAs was different. It was concluded that the relative changes of the circulating microRNA-133a, -486 and 126 expression rates of both players differed in response to tennis match-play with respect to the experienced physiological-perceptual stress and the underlying fitness level. Therefore, circulating microRNAs can serve as additional biomarkers for tennis exercise physiology and may be assessed together with standard markers to conclude whether key cellular regulatory processes were induced in response to match-play.


2017 ◽  
Vol 12 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Padraic J Phibbs ◽  
Ben Jones ◽  
Gregory AB Roe ◽  
Dale B Read ◽  
Joshua Darrall-Jones ◽  
...  

Limited information is available regarding the training loads of adolescent rugby union players. One-hundred and seventy male players (age 16.1 ± 1.0 years) were recruited from 10 teams representing two age categories (under-16 and under-18) and three playing standards (school, club and academy). Global positioning systems, accelerometers, heart rate and session-rating of perceived exertion (s-RPE) methods were used to quantify mean session training loads. Session demands differed between age categories and playing standards. Under-18 academy players were exposed to the highest session training loads in terms of s-RPE (236 ± 42 AU), total distance (4176 ± 433 m), high speed running (1270 ± 288 m) and PlayerLoad™ (424 ± 56 AU). Schools players had the lowest session training loads in both respective age categories. Training loads and intensities increased with age and playing standard. Individual monitoring of training load is key to enable coaches to maximise player development and minimise injury risk.


2013 ◽  
Vol 21 (1) ◽  
pp. 100-111 ◽  
Author(s):  
Lars Donath ◽  
Lukas Zahner ◽  
Mareike Cordes ◽  
Henner Hanssen ◽  
Arno Schmidt-Trucksäss ◽  
...  

The study investigated physiological responses during 2-km walking at a certain intensity of a previously performed maximal exercise test where moderate perceived exertion was reported. Twenty seniors were examined by an incremental walking treadmill test to obtain maximal oxygen uptake (VO2max). A submaximal 2-km walking test was applied 1 wk later. The corresponding moderate perceived exertion (4 on the CR-10 scale) during the VO2maxtest was applied to the 2-km treadmill test. Moderate exertion (mean rating of perceived exertion [RPE]: 4 ± 1) led to 76% ± 8% of VO2maxand 79% ± 6% of maximal heart rate. RPE values drifted with a significant time effect (p= .001, ηp= .58) during the 2-km test from 3 ± 0.7 to 4.6 ± 0.8. Total energy expenditure (EE) was 3.3 ± 0.5 kcal/kg. No gender differences in ventilatory, heart-rate, or EE data occurred. Brisk walking at moderate RPE of 3–5 would lead to a beneficial physiological response during endurance training and a weekly EE of nearly 1,200 kcal when exercising 5 times/wk for 30 min.


Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3797
Author(s):  
Aline V. Caris ◽  
Ronaldo V. Thomatieli-Santos

The rating of perceived exertion (RPE) indicates the feeling of fatigue. However, hypoxia worsens the condition and can worsen RPE. We evaluated whether carbohydrate and glutamine supplementation alters RPE and physiological markers in running at 70% peak oxygen uptake until exhaustion in a simulated altitude of 4500 m. Nine volunteers underwent three running tests at 70% peak oxygen uptake until exhaustion: (1) hypoxia and placebo, (2) hypoxia and 8% maltodextrin, and (3) hypoxia after six days of glutamine supplementation (20 g/day) and 8% maltodextrin. The exercise and supplementation were randomized and double-blinded. Lactate, heart rate, haemoglobin O2 saturation (SpO2%), and RPE (6–20 scale) were analyzed at the 15th and 30th min. The level of significance was set at p ≤ 0.05. SpO2% decreased at the 15th and 30th minutes compared to resting in placebo, carbohydrate, and glutamine supplementation. RPE increased at the 30th minute compared to the 15th minute in placebo and carbohydrate supplementation; however, there was no difference in the glutamine supplementation condition. Heart rate and lactate increased after the 15th and 30th minutes compared to resting, similar to the three conditions studied. We conclude that previous supplementation with glutamine and carbohydrate during intense exercise in hypoxia similar to 4500 m can attenuate the increase in RPE by the increase in glycemia and can be a useful strategy for people who exercise in these conditions.


Author(s):  
Cristina Cortis ◽  
Andrea Fusco ◽  
Mitchell Cook ◽  
Scott T. Doberstein ◽  
Cordial Gillette ◽  
...  

Although cycling class intensity can be modified by changing interval intensity sequencing, it has not been established whether the intensity order can alter physiological and perceptual responses. Therefore, this study aimed to determine the effects of interval intensity sequencing on energy expenditure (EE), physiological markers, and perceptual responses during indoor cycling. Healthy volunteers (10 males = 20.0 ± 0.8years; 8 females = 21.3 ± 2.7years) completed three randomly ordered interval bouts (mixed pyramid—MP, ascending intervals—AI, descending intervals—DI) including three 3-min work bouts at 50%, 75%, and 100% of peak power output (PPO) and three 3-min recovery periods at 25% PPO. Heart rate (HR) and oxygen consumption (VO2) were expressed as percentages of maximal HR (%HRmax) and VO2 (%VO2max). EE was computed for both the work bout and for the 5-min recovery period. Session Rating of Perceived Exertion (sRPE) and Exercise Enjoyment Scale (EES) were recorded. No differences emerged for % HRmax (MP = 73.3 ± 6.1%; AI = 72.1 ± 4.9%; DI = 71.8 ± 4.5%), % VO2max (MP = 51.8 ± 4.6%; AI = 51.4 ± 3.9%; DI = 51.3 ± 4.5%), EE (MP = 277.5 ± 39.9 kcal; AI = 275.8 ± 39.4 kcal; DI = 274.9 ± 42.1 kcal), EES (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9), and sRPE (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9). EE during recovery was significantly (p < 0.005) lower after DI (11.9 ± 3.2 kcal) with respect to MP (13.2 ± 2.5 kcal) and AI (13.3 ± 2.5 kcal). Although lower EE was observed during recovery in DI, interval intensity sequencing does not affect overall EE, physiological markers, and perceptual responses.


Author(s):  
Alice Iannaccone ◽  
Daniele Conte ◽  
Cristina Cortis ◽  
Andrea Fusco

Internal load can be objectively measured by heart rate-based models, such as Edwards’ summated heart rate zones, or subjectively by session rating of perceived exertion. The relationship between internal loads assessed via heart rate-based models and session rating of perceived exertion is usually studied through simple correlations, although the Linear Mixed Model could represent a more appropriate statistical procedure to deal with intrasubject variability. This study aimed to compare conventional correlations and the Linear Mixed Model to assess the relationships between objective and subjective measures of internal load in team sports. Thirteen male youth beach handball players (15.9 ± 0.3 years) were monitored (14 training sessions; 7 official matches). Correlation coefficients were used to correlate the objective and subjective internal load. The Linear Mixed Model was used to model the relationship between objective and subjective measures of internal load data by considering each player individual response as random effect. Random intercepts were used and then random slopes were added. The likelihood-ratio test was used to compare statistical models. The correlation coefficient for the overall relationship between the objective and subjective internal data was very large (r = 0.74; ρ = 0.78). The Linear Mixed Model using both random slopes and random intercepts better explained (p < 0.001) the relationship between internal load measures. Researchers are encouraged to apply the Linear Mixed Models rather than correlation to analyze internal load relationships in team sports since it allows for the consideration of the individuality of players.


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