Monitoring fatigue and recovery in team sport athletes

"This thesis details two consecutive studies. The first was a prospective study examining changes in previously identified markers of fatigue and recovery during six weeks of physical training that was designed to deliberately overreach semi-professional rugby league players. The second study examined changes in these markers during a seven day taper prior to the commencement of the competition period." -- abstract

Monitoring changes in rugby league players' perceived stress and recovery during intensified training

This study assessed if the recovery stress questionnaire (RESTQ-Sport) could be used to monitor changes in perceived stress and recovery during intensified training in rugby league players. Twenty semi-professional rugby league players were divided into two even groups that were randomly assigned to complete six weeks of Normal Training or Intensified Training, each followed with a seven day taper. Multistage fitness test performance and RESTQ-Sport measures were taken at the beginning, at fortnightly intervals and at the end of the training period. Endurance performance significantly decreased with Intensified Training and returned to baseline levels following the taper, while remaining unchanged in the Normal Training group. There was also a relationship between the RESTQ-Sport scores with training, with stress subscales (Fatigue, Disturbed Breaks, and General Stress) increasing and recovery subscale measures (Success, Physical Recovery, Being in Shape, Self Efficacy, Social Relaxation, General Well-Being, and Sleep Quality) decreasing in the Intensified Training group and then normalising following the taper (Stress subscales: Fatigue and General Stress; Recovery subscales: Physical Recovery and General Well-Being). These results show that the RESTQ-Sport is a practical psychometric tool for monitoring responses to training in team sport athletes

Urinalyses and body mass changes during an ultra-distance endurance event : the Simpson Desert cycle challenge

Hypohydration during high intensity and I or prolonged exercise in thermally stressful environments may lead to decreases in physical performance, thermoregulatory ability and cardiovascular function (1). Athletes competing in thermally stressful environments are advised to observe sweat losses and measure both fluid intake and body mass in order to monitor fluid losses. However, these techniques may not be accurate unless all food intake, fluid intake, sweat loss, respiratory fluid loss, and faeces losses are accurately monitored (2). It has also recently been suggested that urinalysis is a valid and non-invasive screening tool to monitor hydration status in athletes (2). The purpose of the present study was to describe the body mass and urine changes that occurred over a five-day, 580 km multi-stage cycling race (Simpson Desert Cycle Challenge - SDCC) across Australia's Simpson Desert in ambient temperatures ranging from 16-47 °c

Heart rate, blood lactate concetration and estimated energy expediture in a semi-professional rugby league team during a match : a case study

The aim of this study was to examine heart rate, blood lactate concentration and estimated energy expenditure during a competitive rugby league match. Seventeen well-trained rugby league players (age, 23.9 +/- 4.1 years; VO2max, 57.9 +/- 3.6 ml.kg-1.min-1; height, 1.82 +/- 0.06 m; body mass, 90.2 +/- 9.6 kg; mean +/- s) participated in the study. Heart rate was recorded continuously throughout the match using Polar Vantage NV recordable heart rate monitors. Blood lactate samples (n = 102) were taken before the match, after the warm-up, at random stoppages in play, at half time and immediately after the match. Estimated energy expenditure during the match was calculated from the heart rate-VO2 relationship determined in laboratory tests. The mean team heart rate (n= 15) was not significantly different between halves (167 +/- 9 vs 165 +/- 11 beats.min-1). Mean match intensity was 81.1 +/- 5.8 % VO2max. Mean match blood lactate concentration was 7.2 +/- 2.5 mmol-1-1, with concentrations for the first half (8.4 +/- 1.8 mmol.1-1) being significantly higher than those for the second half (5.9 +/- 2.5 mmol.1-1) (P < 0.05). Energy expenditure was approximately 7.9 MJ. These results demonstrate that semi-professional rugby league is a highly aerobic game with a considerable anaerobic component requiring high lactate tolerance. Training programmes should reflect these demands placed on players during competitive match-play

Monitoring for overreaching in rugby league players

The aim of this study was to identify indicators of non-functional overreaching (NFOR) in team sport athletes undertaking intensive training loads. Eighteen semi-professional rugby league players were randomly assigned into two pair matched groups. One group completed 6 weeks of normal training (NT) whilst the other group was deliberately overreached through intensified training (IT). Both groups then completed the same 7-day stepwise training load reduction taper. Multistage fitness test (MSFT) performance, , peak aerobic running velocity (V max), maximal heart rate, vertical jump, 10-s cycle sprint performance and body mass were measured pre- and post-training period and following the taper. Hormonal, haematological and immunological parameters were also measured pre-training and following weeks 2, 4 and 6 of training and post-taper. MANOVA for repeated measures with contrast analysis indicated that MSFT performance and were significantly reduced in the IT group over time and condition, indicating that a state of overreaching was attained. However, the only biochemical measure that was significantly different between the IT and NT group was the glutamine to glutamate (Gln/Glu) ratio even though testosterone, testosterone to cortisol (T/C) ratio, plasma glutamate, and CK activity were significantly changed after training in both groups. Positive endurance and power performance changes were observed post-taper in the IT group confirming NFOR. These changes were associated with increases in the T/C ratio and the Gln/Glu ratio and decreases in plasma glutamate and CK activity. These results indicate that although there was no single reliable biochemical marker of NFOR in these athletes, the Gln/Glu ratio and MSFT test may be useful measures for monitoring responses to IT in team sport athletes

The effect of glycerol hyperhydration on Olympic distance triathlon performance in high ambient temperatures

The purpose ofthis study was to examine the effect ofprior glycerol loading on competitive Olympic distance triathlon performance (ODT) in high ambient temperatures. Ten (3 female and 7 male) well-trained triathletes (VOzmax = 58.4 ± 2.4 mI· kg-I. min-J ; bestODT time = 131.5 ± 2.6 min) completed 2 ODTs (1.5-km swim, 40-km bicycle, lO-km run) in a randomly assigned (placebo/glycerol) double-blind study conducted 2 weeks apart. The wet-bulb globe temperature (outdoors) was 30.5 ± 0.5 °C (relative humidity: 46.3 ± 1.1 %; hot) and 25.4 ± 0.2 °C (relative humidity: 51.7 ± 2.4%; warm) for day 1 and day 2, respectively. The glycerol solution consisted of 1.2 g of glycerol per kilogram of body mass (BM) and 25 ml of a 0.75 g . kg- J BM carbohydrate solution (Gatorade®) and was consumed over a 60-min period, 2 hours prior to each ODT. Measures of performance (ODT time), fluid retention, urine output, blood plasma volume changes, and sweat loss were obtained prior to and during the ODT in both the glycerol and placebo conditions. Following glycerol loading, the increase in ODT completion time between the hot and warmconditions was significantly less than the placebo group (placebo 11:40 min vs. glycerol 1:47 min; p < .05). The majority of the performance improvement occurred during the finallO-kmrun leg ofODTon the hot day. Hyperhydration occurred as a consequence of a reduced diuresis (p < .05) and a subsequent increase in fluid retention (p < .05). No significant differences were observed in sweat loss between the glycerol and placebo conditions. Plasma volume expansion during the loading period was significantly greater (p < .05) on the hot day when glycerol appeared to attenuate the performance decrement in the heat. The present reSults suggest that glycerol hyperhydration prior to ODTin high ambient temperatures may provide some protection against the negative performance effects of competing in the heat

Changes in selected biochemical, muscular strength, power, and endurance measures during deliberate overreaching and tapering in rugby league players

The purpose of this study was to examine the influence of overreaching on muscle strength, power, endurance and selected biochemical responses in rugby league players. Seven semi-professional rugby league players (V·O 2max = 56.1 ± 1.7 mL · kg -1 · min -1; age = 25.7 ± 2.6 yr; BMI = 27.6 ± 2.0) completed 6 weeks of progressive overload training with limited recovery periods. A short 7-day stepwise reduction taper immediately followed the overload period. Measures of muscular strength, power and endurance and selected biochemical parameters were taken before and after overload training and taper. Multistage fitness test running performance was significantly reduced (12.3 %) following the overload period. Although most other performance measures tended to decrease following the overload period, only peak hamstring torque at 1.05 rad · s -1 was significantly reduced (p < 0.05). Following the taper, a significant increase in peak hamstring torque and isokinetic work at both slow (1.05 rad · s -1) and fast (5.25 rad · s -1) movement velocities were observed. Minimum clinically important performance decreases were measured in a multistage fitness test, vertical jump, 3 RM squat and 3-RM bench press and chin-up max following the overload period. Following the taper, minimum clinically important increases in the multistage fitness test, vertical jump, 3-RM squat and 3-RM bench press and chin-up max and 10-m sprint performance were observed. Compared to resting measures, the plasma testosterone to cortisol ratio, plasma glutamate, plasma glutamine to glutamate ratio and plasma creatine kinase activity demonstrated significant changes at the end of the overload training period (p < 0.05). These results suggest that muscular strength, power and endurance were reduced following the overload training, indicating a state of overreaching. The most likely explanation for the decreased performance is increased muscle damage via a decrease in the anabolic-catabolic balance

The reliability of the i-STAT clinical portable analyser

The purpose of this investigation was to assess the reliability of the i-STAT clinical portable analyser and CG(4)(+) cartridge measures of blood pH, partial pressures of O(2) (pO(2)) and CO(2) (pCO(2)), bicarbonate ([HCO(3)(-)]), base excess (BE), total carbon dioxide (TCO(2)), oxygen saturation (sO(2)) and blood lactate ([BLa(-)]) at various exercise intensities. A comparison between [BLa(-)] measured by the i-STAT and the Accusport lactate analysers during an intermittent treadmill run was also undertaken. The technical error of measurement (TEM%) at rest, at moderate (200W) and maximal exercise (V O(2)max) was acceptable (4mmolL(-1)) (0.58+/-1.22mmolL(-1)), and across all [BLa(-)] data (0.36+/-1.13mmolL(-1)). In conclusion, the i-STAT clinical analyser and CG(4)(+) cartridge provides reliable measures of a number of blood parameters across exercise intensities. The [BLa(-)] measures from the i-STAT analyser are consistent with that of the Accusport lactate analyser

Effect of post-match cold-water immersion on subsequent match running performance in junior soccer players during tournament play

In this study, we investigated the effects of two hydrotherapy interventions on match running performance and perceptual measures of fatigue and recovery during a 4-day soccer tournament. Twenty male junior soccer players were assigned to one of two treatment groups and undertook either cold-water immersion (5 1 min at 10°C) or thermoneutral water immersion (5 1 min at 34°C) after each match. High-intensity running distance (>15 km · h-1) and total distance covered, time spent in low (90% maximum heart rate) heart rate zones, and rating of perceived exertion (RPE) were recorded for each match. Perceptions of general fatigue and leg soreness were recorded approximately 22 h after each match. There were decreases in both groups across the 4-day tournament for high-intensity running distance (P = 0.006, Cohen's d = 0.63), total distance run (P < 0.001, d = 0.90), time in high heart rate zone (P = 0.003, d = 0.90), and match RPE (P = 0.012, d = 0.52). Cold-water immersion was more effective than thermoneutral immersion for reducing the perception of leg soreness (P = 0.004, d = -0.92) and general fatigue (P = 0.007, d = -0.91), ameliorating the decrement in total distance run (P = 0.001, d = 0.55), and maintaining time in the moderate heart rate zone (P = 0.01, d = 1.06). In conclusion, cold-water immersion mediates the perceptions of fatigue and recovery and enhances the restoration of some match-related performance measures during a 4-day tournament

Effects of cold-water immersion on physical performance between successive matches in high-performance junior male soccer players

In this study, we investigated the effect of water immersion on physical test performance and perception of fatigue/recovery during a 4-day simulated soccer tournament. Twenty high-performance junior male soccer players (age 15.9 ± 0.6 years) played four matches in 4 days and undertook either cold-water immersion (10 ± 0.5°C) or thermoneutral water immersion (34 ± 0.5°C) after each match. Physical performance tests (countermovement jump height, heart rate, and rating of perceived exertion after a standard 5-min run and 1220-m repeated sprint test), intracellular proteins, and inflammatory markers were recorded approximately 90 min before each match and 22 h after the final match. Perceptual measures of recovery (physical, mental, leg soreness, and general fatigue) were recorded 22 h after each match. There were non-significant reductions in countermovement jump height (1.7-7.3%, P = 0.74, η2 = 0.34) and repeated sprint ability (1.0-2.1%, P = 0.41, η2 = 0.07) over the 4-day tournament with no differences between groups. Post-shuttle run rating of perceived exertion increased over the tournament in both groups (P < 0.001, η2 = 0.48), whereas the perceptions of leg soreness (P = 0.004, η2 = 0.30) and general fatigue (P = 0.007, η2 = 0.12) were lower in the cold-water immersion group than the thermoneutral immersion group over the tournament. Creatine kinase (P = 0.004, η2 = 0.26) and lactate dehydrogenase (P < 0.001, η2 = 0.40) concentrations increased in both groups but there were no changes over time for any inflammatory markers. These results suggest that immediate post-match cold-water immersion does not affect physical test performance or indices of muscle damage and inflammation but does reduce the perception of general fatigue and leg soreness between matches in tournaments