Age-related differences in post-exercise recovery following high-intensity exercise in masters and young cyclists

The purpose of this thesis and associated series of studies was to compare the acute (1 hrs) in well-trained masters and young cyclists following a high-intensity interval training bout (HIT). The thesis comprises of five manuscripts. Manuscript 1 in Chapter 2 is a narrative literature review published in the Journal of Aging and Physical Activity which examines the significance of the masters athlete population, the importance of recovery for athletes, and the effect of age on recovery following exercise. Manuscripts 2-4 in Chapters 3- 5 investigate age-related differences in acute physiological recovery parameters and Manuscript 5 in Chapter 6 examines differences in chronic parameters of recovery

Wearable lactate threshold predicting device is valid and reliable in runners

Wearable lactate threshold predicting device is valid and reliable in runners. J Strength Cond Res 30(8): 2212-2218, 2016 - A commercially available device claiming to be the world's first wearable lactate threshold predicting device (WLT), using near-infrared LED technology, has entered the market. The aim of this study was to determine the levels of agreement between the WLT-derived lactate threshold workload and traditional methods of lactate threshold (LT) calculation and the interdevice and intradevice reliability of the WLT. Fourteen (7 male, 7 female; mean ± SD; age: 18-45 years, height: 169 ± 9 cm, mass: 67 ± 13 kg, Vo 2 max: 53 ± 9 ml·kg -1 ·min -1) subjects ranging from recreationally active to highly trained athletes completed an incremental exercise test to exhaustion on a treadmill. Blood lactate samples were taken at the end of each 3-minute stage during the test to determine lactate threshold using 5 traditional methods from blood lactate analysis which were then compared against the WLT predicted value. In a subset of the population (n 12), repeat trials were performed to determine both inter-reliability and intrareliability of the WLT device. Intraclass correlation coefficient (ICC) found high to very high agreement between the WLT and traditional methods (ICC > 0.80), with TEMs and mean differences ranging between 3.9-10.2% and 1.3-9.4%. Both interdevice and intradevice reliability resulted in highly reproducible and comparable results (CV 0.97). This study suggests that the WLT is a practical, reliable, and noninvasive tool for use in predicting LT in runners. © 2015 National Strength and Conditioning Association.Borges, NR and Driller, MW

The commonality between approaches to determine jump fatigue during basketball activity in junior players: In-game versus across-game decrements

© 2017 Human Kinetics, Inc. Purpose: Declines in high-intensity activity during game play (in-game approach) and performance tests measured pre-and postgame (across-game approach) have been used to assess player fatigue in basketball. However, a direct comparison of these approaches is not available. Consequently, this study examined the commonality between in-and across-game jump fatigue during simulated basketball game play. Methods: Australian, state-level, junior male basketball players (n = 10; 16.6 ± 1.1 y, 182.4 ± 4.3 cm, 68.3 ± 10.2 kg) completed 4 × 10-min standardized quarters of simulated basketball game play. In-game jump height during game play was measured using video analysis, while across-game jump height was determined pre-, mid-, and postgame play using an in-ground force platform. Jump height was determined using the flight-time method, with jump decrement calculated for each approach across the frst half, second half, and entire game. Results: A greater jump decrement was apparent for the in-game approach than for the across-game approach in the frst half (37.1% ± 11.6% vs 1.7% ± 6.2%; P =.005; d = 3.81, large), while nonsignifcant, large differences were evident between approaches in the second half (d = 1.14) and entire game (d = 1.83). Nonsignifcant associations were evident between in-game and across-game jump decrement, with shared variances of 3-26%. Conclusions: Large differences and a low commonality were observed between in-and across-game jump fatigue during basketball game play, suggesting that these approaches measure different constructs. Based on our fndings, it is not recommended that basketball coaches use these approaches interchangeably to monitor player fatigue across the season

Hydration status of rugby union players in hot and humid conditions: A comparative team case study of day and night training sessions

© 2017, University of Stellenbosch. All rights reserved. Hydration responses of rugby union players within and between day and night training sessions in hot and humid conditions were monitored. Body mass, fluid ingestion, perceptual thermal stress (TSS) and thirst scores were monitored in ten players (age: 21.9±4.4 years; body mass: 97.9±15.5kg; height: 179.5±5.6cm) across both training sessions. Heat index was higher during the day session compared to the night (44°C vs 34°C respectively). Significant interaction effects were found for body mass and TSS. Between-group comparisons revealed no significant fluctuations of body mass between sessions. Temporal comparisons showed a significant reduction in body mass across the night session (97.2±15.7; 96.4±15.4 kg), although the mean decrease in body mass did not exceeded > 2%. TSS increased significantly across both day (1.2±1.3; 5.2±1.0) and night sessions (1.4±1.0; 3.6±1.6). However, TSS was significantly higher post-training in the day session and players ingested more fluids during the day session (1.4±0.5; 0.9±0.4 L·hr -1 ). Reduced thermal stress scores may compromise self-mediated hydration practices in rugby players when training at night and lead to greater body mass loss

Concurrent resistance training and flying 200-meter time trial program for a masters track cyclist

National Strength and Conditioning Association.Participation numbers in masters track cycling demonstrate that track cycling is becoming an increasingly popular sport for masters’ athletes. Despite this, research focused on performance enhancement for masters track cyclists is lacking. Age-related changes in morphological and neuromuscular factors affect sprint performance and present strength and conditioning coaches with significant challenges. this article therefore aims to justify the inclusion of a concurrent resistance training and flying 200-m time trail program as an intervention to increase the flying 200-m performance of a masters track cyclist (see, video, supplemental digital content 1, http://links.lww.com/scj/a182). © 201

The effect of higher than recommended protein feedings post-exercise on recovery following downhill running in masters triathletes

Following exercise-induced muscle damage (EIMD), masters athletes take longer to recover than younger athletes. The purpose of this study was to determine the effect of higher than recommended postexercise protein feedings on the recovery of knee extensor peak isometric torque (PIT), perceptions of recovery, and cycling time trial (TT) performance following EIMD in masters triathletes. Eight masters triathletes (52 ?} 2 y, V?O2max, 51.8 ?} 4.2 ml•kg-1•min-1) completed two trials separated by seven days in a randomized, doubleblind, crossover study. Trials consisted of morning PIT testing and a 30-min downhill run followed by an eight-hour recovery. During recovery, a moderate (MPI; 0.3 g•kg-1•bolus-1) or high (0.6 g•kg-1•bolus-1) protein intake (HPI) was consumed in three bolus feedings at two hour intervals commencing immediately postexercise. PIT testing and a 7 kJ•kg-1 cycling TT were completed postintervention. Perceptions of recovery were assessed pre-And postexercise. The HPI did not significantly improve recovery compared with MPI (p > .05). However, comparison of within-Treatment change shows the HPI provided a moderate beneficial effect (d = 0.66), attenuating the loss of afternoon PIT (-3.6%, d = 0.09) compared with the MPI (-8.6%, d = 0.24). The HPI provided a large beneficial effect (d = 0.83), reducing perceived fatigue over the eight-hour recovery (d = 1.25) compared with the MPI (d = 0.22). Despite these effects, cycling performance was unchanged (HPI = 2395 ?} 297 s vs. MPI = 2369 ?} 278 s; d = 0.09). In conclusion, doubling the recommended postexercise protein intake did not significantly improve recovery in masters athletes; however, HPI provided moderate to large beneficial effects on recovery that may be meaningful following EIMD. © 2017 Human Kinetics, Inc

Age-related changes in physical and perceptual markers of recovery following high-intensity interval cycle exercise

Background: The purpose of this study was to compare physical performance, perceptual and haematological markers of recovery in well-trained masters and young cyclists across 48 h following a bout of repeated high-intensity interval exercise. Methods: Nine masters (mean ± SD; age = 55.6 ± 5.0 years) and eight young (age = 25.9 ± 3.0 years) cyclists performed a high-intensity interval exercise session consisting of 6 × 30 s intervals at 175% peak power output with 4.5 min rest between efforts. Maximal voluntary contraction (MVC), 10 s sprint (10SST), 30-min time trial (30TT) performance, creatine kinase concentration (CK) and perceptual measures of motivation, total recovery, fatigue and muscle soreness were collected at baseline and at standardised time points across the 48 h recovery period. Results: No significant group-time interactions were observed for performance of MVC, 10SST, 30TT and CK (P > 0.05). A significant reduction in 10SST peak power was found in both masters (P = 0.002) and young (P = 0.003) cyclists at 1 h post exercise, however, both groups physically recovered at similar rates. Neither group showed significant (P > 0.05) or practically meaningful increases in CK (%∆ < 10%). A significant age-related difference was found for perceptual fatigue (P = 0.01) and analysis of effect size (ES) showed that perceptual recovery was delayed with masters cyclists reporting lower motivation (ES ±90%CI = 0.69 ± 0.77, moderate), greater fatigue (ES = 0.75 ± 0.93, moderate) and muscle soreness (ES = 0.61 ± 0.70, moderate) after 48 h of recovery. Conclusion: The delay in perceived recovery may have negative effects on long-term participation to systematic training. © 2018, © 2018 Taylor & Francis Group, LLC

Training mode’s influence on the relationships between training-load models during basketball conditioning

Purpose: To compare perceptual and physiological training load responses during various basketball training modes. Methods: Eight semi-professional male basketball players (age: 26.3 ± 6.7 years; height: 188.1 ± 6.2 cm; body mass: 92.0 ± 13.8 kg) were monitored across a 10-week period in the preparatory phase of the training plan. Player session ratings of perceived exertion (sRPE) and heart rate (HR) responses were gathered across base, specific, and tactical/game-play training modes. Pearson correlations were used to determine the relationships between the sRPE model and two HR-based models, the training impulse (TRIMP) and summated-heart-rate-zones (SHRZ). One-way ANOVAs were used to compare training loads between training modes for each model. Results: Stronger relationships between perceptual and physiological models were evident during base (sRPE-TRIMP: r = 0.53, P < 0.05; sRPE-SHRZ: r = 0.75, P < 0.05) and tactical/game-play conditioning (sRPE-TRIMP: r = 0.60, P < 0.05; sRPE-SHRZ: r = 0.63; P < 0.05) than during specific conditioning (sRPE-TRIMP: r = 0.38, P < 0.05; sRPE-SHRZ: r = 0.52; P < 0.05). Further, the sRPE model detected greater increases (126-429 AU) in training load than the TRIMP (15-65 AU) and SHRZ models (27-170 AU) transitioning between training modes. Conclusions: While the training load models were significantly correlated during each training mode, weaker relationships were observed during specific conditioning. Comparisons suggest the HR-based models were less effective in detecting periodized increases in training load, particularly during court-based, intermittent, multidirectional drills. The practical benefits and sensitivity of the sRPE model support its use across different basketball training modes

Temporal changes in physiological and performance responses across game-specific simulated basketball activity

© 2016. Purpose: The aims of this study were to: (1) provide a comprehensive physiological profile of simulated basketball activity and (2) identify temporal changes in player responses in controlled settings. Methods: State-level male basketball players (n = 10) completed 4 × 10 min simulated quarters of basketball activity using a reliable and valid court-based test. A range of physiological (ratings of perceived exertion, blood lactate concentration ([BLa - ]), blood glucose concentration ([BGlu] ), heart rate (HR), and hydration) and physical (performance and fatigue indicators for sprint, circuit, and jump activity) measures were collected across testing. Results: Significantly reduced [BLa - ] (6.19 ± 2.30 vs. 4.57 ± 2.33 mmol/L; p = 0.016) and [BGlu] (6.91 ± 1.57 vs. 5.25 ± 0.81 mmol/L; p = 0.009) were evident in the second half. A mean HR of 180.1 ± 5.7 beats/min (90.8% ± 4.0% HR max ) was observed, with a significant increase in vigorous activity (77%-95% HR max ) (11.31 ± 6.91 vs. 13.50 ± 6.75 min; p = 0.024) and moderate decrease in near-maximal activity ( > 95% HR max ) (7.24 ± 7.45 vs. 5.01 ± 7.20 min) in the second half. Small increases in performance times accompanied by a significantly lower circuit decrement (11.67% ± 5.55% vs. 7.30% ± 2.16%; p = 0.032) were apparent in the second half. Conclusion: These data indicate basketball activity imposes higher physiological demands than previously thought and temporal changes in responses might be due to adapted pacing strategies as well as fatigue-mediated mechanisms

Cumulative training dose's effects on interrelationships between common training-load models during basketball activity

Purpose: The influence of various factors on training-load (TL) responses in basketball has received limited attention. This study aimed to examine the temporal changes and influence of cumulative training dose on TL responses and interrelationships during basketball activity. Methods: Ten state-level Australian male junior basketball players completed 4 × 10-min standardized bouts of simulated basketball activity using a circuit-based protocol. Internal TL was quantifed using the session rating of perceived exertion (sRPE), summated heart-rate zones (SHRZ), Banister training impulse (TRIMP), and Lucia TRIMP models. External TL was assessed via measurement of mean sprint and circuit speeds. Temporal TL comparisons were performed between 10-min bouts, while Pearson correlation analyses were conducted across cumulative training doses (0-10, 0-20, 0-30, and 0-40 min). Results: sRPE TL increased (P < .05) after the frst 10-min bout of basketball activity. sRPE TL was only signifcantly related to Lucia TRIMP (r =.66-.69; P < .05) across 0-10 and 0-20 min. Similarly, mean sprint and circuit speed were signifcantly correlated across 0-20 min (r =.67; P < .05). In contrast, SHRZ and Banister TRIMP were signifcantly related across all training doses (r =.84-.89; P < .05). Conclusions: Limited convergence exists between common TL approaches across basketball training doses lasting beyond 20 min. Thus, the interchangeability of commonly used internal and external TL approaches appears dose-dependent during basketball activity, with various psychophysiological mediators likely underpinning temporal changes. © 2017 Human Kinetics, Inc