Nattai R. Borges

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 semiprofessional male basketball players (age 26.3 ± 6.7 y, height 188.1 ± 6.2 cm, body mass 92.0 ± 13.8 kg) were monitored across a 10-wk period in the preparatory phase of their 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 2 HR-based models: the training impulse (TRIMP) and summated HR 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 = .53, P < .05; sRPE-SHRZ r = .75, P < .05) and tactical/game-play conditioning (sRPE-TRIMP r = .60, P < .05; sRPE-SHRZ r = .63; P < .05) than during specific conditioning (sRPE-TRIMP r = .38, P < .05; sRPE-SHRZ r = .52; P < .05). Furthermore, 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 that 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.

Age-Related Changes in Performance and Recovery Kinetics in Masters Athletes: A Narrative Review

Despite increasing participation rates in masters sport and extensive research examining age-related changes in performance, little is known about the effect of age on recovery kinetics in masters athletes. This narrative review focuses on the relationship between aging and sport participation, and the effect on both performance and recovery following an exercise bout. Current research suggests the effect of age on performance and recovery may be smaller than originally suggested and that increasing sedentary lifestyles appear to play a larger role in any observed decrements in performance and recovery in masters athletes. Currently, it appears that performance decrements are inevitable with age. However, performance capacities can be maintained through systematic physical training. Moreover, the limited current research suggests there may be an age effect on recovery kinetics following an exercise bout, although further research is required to understand the acute and chronic recovery processes in the masters athlete.

Wearable Lactate Threshold Predicting Device is Valid and Reliable in Runners

Abstract Borges, NR and Driller, MW. 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 worlds 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, V[Combining Dot Above]O2max: 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 < 1.2%, TEM <0.2 km·h−1, ICC > 0.97). This study suggests that the WLT is a practical, reliable, and noninvasive tool for use in predicting LT in runners.

Lower Integrated Muscle Protein Synthesis in Masters Compared with Younger Athletes.

PURPOSE The objective of this study is to compare the integrated muscle protein synthesis (MPS) rates of masters and younger triathletes over three consecutive days of intense endurance training. Recovery of cycling performance, after muscle-damaging running, was also compared between groups. METHODS Five masters (age, 53 ± 2 yr; V˙O2max, 55.7 ± 6.9 mL·kg·min) and six younger (age, 27 ± 2 yr; V˙O2max, 62.3 ± 1.5 mL·kg·min) trained triathletes volunteered for the study. Baseline skeletal muscle and saliva were initially sampled, after which a 150-mL bolus of deuterium oxide (70%) was consumed. Participants then completed a 30-min downhill run; three 20-km cycling time trials (TT) were completed 10, 24, and 48 h after the run. Saliva was collected each morning, and skeletal muscle was again sampled 72 h after the run; both were used for MPS analysis. Diet was controlled throughout the study. RESULTS Over 3 d, masters triathletes showed a significantly lower myofibrillar fractional synthetic rate (1.49% ± 0.12%·d) compared with the younger (1.70% ± 0.09%·d) triathletes (P = 0.009, d = 1.98). There was also a trend for masters triathletes to produce a slower cycle TT (-3.0%, d = 0.46) than younger triathletes (-1.4%, d = 0.29) at 10 h postrun in comparison with the baseline performance. The between-group comparison of change was moderate (d = 0.51), suggesting slower acute recovery among masters triathletes. CONCLUSIONS The present data show lower MPS rates in well-trained masters triathletes over 3 d of training, and this likely contributes to poorer muscle protein repair and remodeling. Furthermore, acute recovery of cycle TT performance tended to be poorer in the masters triathletes.

Cumulative Training Dose Alters the 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 quantified 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 first 10-min bout of basketball activity. sRPE TL was only significantly related to Lucia TRIMP (r = .66-.69; P < .05) across 0-10 and 0-20 min. Similarly, mean sprint and circuit speed were significantly correlated across 0-20 min (r = .67; P < .05). In contrast, SHRZ and Banister TRIMP were significantly 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.

The Commonality Between Approaches to Determine Jump Fatigue During Basketball Activity in Junior Players: In-Game Versus Across-Game Decrements

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 first 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 first half (37.1% ± 11.6% vs 1.7% ± 6.2%; P = .005; d = 3.81, large), while nonsignificant, large differences were evident between approaches in the second half (d = 1.14) and entire game (d = 1.83). Nonsignificant 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 findings, it is not recommended that basketball coaches use these approaches interchangeably to monitor player fatigue across the season.

Wearable near infrared sensor for determining an athlete’s lactate threshold during exercise

Introduction T he determination of an athlete’s lactate threshold (LT) has become an important test performed in sports science laboratories around the world. The lactate threshold or lactate inflection point can be defined as the exercise intensity at which lactate starts to accumulate exponentially in the bloodstream. This threshold occurs when the lactate is produced faster than it can be metabolised during exercise. The most commonly accepted method for measuring LT is determined by a lactate profile test, whereby an athlete exercises at increasing intensities/workloads until volitional exhaustion. The blood lactate samples taken at each stage of the test, usually obtained through an ear/fingerprick or venous sample, are then plotted on a graph against workload/intensity and from this, various methods can be used to determine LT. A number of portable blood lactate analysers have been validated in the sport setting using standardised testing protocols and methodologies, making them common for LT testing. While these analysers have all been shown to be valid and reliable, the limitation of using these analysers to determine LT is that they are invasive, requiring multiple blood samples. This often requires specialist equipment and ongoing consumables, a sterile environment, technical expertise and willing athletes, which is not always practical or possible. For this reason, attempts have been made to develop methods that can “predict” LT using alternative methods that do not require blood sampling. More recently, studies have been testing the use of near infrared (NIR) spectroscopy to gain exercise threshold information via inflection points of muscle oxygenation parameters during incremental exercise. Although the use of NIR spectroscopy is relatively new to sports science, it has proven to be a viable non-invasive tool to determine peripheral muscle oxygenation. A commercially available wearable lactate threshold (WLT) sensor (BSXinsight, BSX Athletics, Texas, USA) is a portable NIR light emitting diode (LED) device which is marketed as the first wearable lactate threshold sensor claiming to have the ability to determine LT during cycling or running exercise tests, without the need for blood samples. The non-invasive and portable nature of the device allows athletes and coaches to monitor their LT with minimal expertise. The WLT uses NIR LEDs to emit light into the gastrocnemius muscle and supposedly measures relative changes in muscle oxygenation and deoxygenation both at a subcutaneous and superficial level on the lower leg. With the data captured during an incremental exercise test, the WLT software then uses a patented algorithm to predict the LT based on the muscle oxygenation deflection/desaturation point. Our laboratory has put the WLT to the test in both runners and cyclists, investigating the accuracy of the device when compared to the more traditional methods of determining an athletes LT, while also determining the interand intra-reliability of the WLT device. This article will outline some of the work our laboratory has performed in evaluating this device.

Decrements in knee extensor and flexor strength are associated with performance fatigue during simulated basketball game-play in adolescent, male players

ABSTRACT This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P < 0.05) related to sprint fatigue in the first half (R = 0.65), with dominant knee flexor strength (R = 0.67) and dominant flexor:extensor strength ratio (R = 0.77) decrement significantly (P < 0.05) associated with sprint decrement across the entire game. Mean knee extensor strength (R = 0.71), dominant knee flexor strength (R = 0.80), non-dominant knee flexor strength (R = 0.75), mean knee flexor strength (R = 0.81), non-dominant flexor:extensor strength ratio (R = 0.71), and mean flexor:extensor strength ratio (R = 0.70) decrement measures significantly (P < 0.05) influenced jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play.

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

ABSTRACT 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.

Reliability of a Cryoscopic Micro-Osmometer Using 15-µL Plasma Samples to Measure Hydration Status in Varied Environmental Conditions.

ABSTRACT Measurement of plasma osmolality (Posm) remains popular for assessing hydration status in exercise science. However, a controlled reliability assessment of micro-osmometry using small sample volumes to measure Posm remains to be performed. This study aimed to examine the reliability of a cryoscopic micro-osmometer requiring 15-μL samples across varied environmental conditions. Thirteen young adults (26.4 ± 5.7 years) completed a 20-min steady-state cycling protocol on separate occasions in cool/dry conditions and hot/humid conditions. Posm was assessed using fingertip capillary samples taken in duplication prior to and following 20-min acclimatization and recovery periods around the cycling bout. Absolute (typical error of measurement = .62–.83 mOsmol·kg–1; coefficient of variation = .9% to 1.3%) and relative (intraclass correlation coefficient = .60–.85) reliability of this approach were supported. These findings suggest micro-osmometry requiring small plasma samples (15 μL) can be reliably used by practitioners to assess longitudinal changes and cross-sectional hydration status in varied environmental conditions.