How Accurate Are Coaches in Predicting Perceived Exertion of Their Athletes?

ABSTRACT: Ryan, GA, Bunn, JA, and Eisenman, ML. How accurate are coaches in predicting perceived exertion of their athletes? J Strength Cond Res 37(3): 684-687, 2023-Ratings of perceived exertion (RPE) are used extensively to subjectively evaluate workload in sport. The purpose of this study was to compare season long player to coach perceptions of RPE loads (RPEL) in Division I men's soccer and women's lacrosse programs. Coach and player self-reported RPE were collected during the competitive seasons for both teams within 30 minutes of training sessions. Scores of RPE were multiplied by recorded training time to determine RPEL and averaged to create a daily coach and player RPEL. Accuracy of RPEL prediction between coaches and players was determined via mean bias, mean absolute percent error (MAPE), correlation, and an equivalence test. Soccer coaches underestimated RPEL (1,345 ± 410 arbitrary unit [AU]) compared with players (1,372 ± 435 AU). The coach mean bias was -27.3 ± 151.9 AU, wieth an MAPE of 7.4%, a strong correlation (r = 0.937, p < 0.001), and coach to player equivalence (p = 0.045). Lacrosse coaches overestimated RPELs (876 ± 349 AU) compared with players (829 ± 214 AU). The coach mean bias was 47 ± 189 AU, with an MAPE of 14.7%, a strong correlation (r = 0.883, p < 0.001), and coach to player equivalence (p = 0.010). Analyses indicated that coaches accurately predicted player RPEL within both sports. Variance occurred on days with high RPELs, with overestimations occurring in lacrosse and underestimation in soccer. Coaches can use RPELs to assess subjective training load but should consider objective measures, including microtechnology, to provide a comprehensive assessment.

Relationship between pre-training wellness scores and internal and external training loads in a Division I women's lacrosse team.

This study examined the relationship between pre-training wellness scores and internal and external training load outputs during the preparation phase of a Division I women's collegiate lacrosse team. Athletes (n = 27) logged daily wellness (sleep, energy, stress, and how their muscles felt), session ratings of perceived exertion, and training metrics for 13 weeks. Load metrics were collected with microtechnology units. Repeated measures mixed linear models were constructed to evaluate the relationships between wellness and training load. The largest effects observed indicated: improved sleep was predictive of increased total distance (by as much as 310.5 m, 95%CI 36.7-584.3), high-intensity distance (by as much as 72.7 m, 95%CI 17.2-128.3), and Athlete Load (by as much as 6.8AU, 95%CI 1.8-11.8); more energy was predictive of increased total distance (by as much as 323.6 m, 95%CI 52.2-594.9) and Athlete Load (by as much as 5.6AU. 95%CI 0.6-10.5). For each one-unit increase in overall wellness score, total distance (3.5 m, 95%CI 1.2-15.1) and Athlete Load (0.2AU, 95%CI 0.0-0.3) increased. Pre-training wellness scores and sub-scores are predictive of external load training output. Monitoring athlete wellness systematically can help coaches with decision-making relevant to training and game performance.

Evaluation of Strength and Conditioning Measures With Game Success in Division I Collegiate Volleyball: A Retrospective Study.

Bunn, JA, Ryan, GA, Button, GR, and, and Zhang, S. Evaluation of strength and conditioning measures with game success in Division I collegiate volleyball: A retrospective study. J Strength Cond Res 34(1): 183-191, 2020-The purpose of this study was to retrospectively assess relationships between strength and conditioning (SC) measures and game performance in Division I volleyball. Five years of SC and game data were collected from 1 women's Division I collegiate team, n = 76. Strength and conditioning measures included T-drill, 18.3 m sprint, back squat, hang clean, vertical jump, and broad jump. All game and SC stats were normalized to Z-scores. Analyses included assessing SC differences by position and multiple stepwise regression to assess relationships between game and SC stats. There was a significant difference by position for broad jump (p = 0.002), 18.3 m sprint (p = 0.036), vertical (p ≤ 0.001), and total strength (p = 0.019). Overall, game performance and SC measures were significantly correlated (r = 0.439, p ≤ 0.001). Multiple regression analyses indicated significant relationships (p ≤ 0.05) between SC measures and game success by position as follows: defensive specialist stats with squat and total strength; setters game stats with hang cleans, T-drill, and broad jump; pin hitter game stats with vertical, squat, and total strength; middle blockers game stats with broad jump. These data indicate that SC measures correlate well with game performance and are specific by position. These data could help SC coaches create a more precise training approach to focus on improving specific measures by position, which could then translate to improved game performance. These data could also help coaches with talent identification to determine playing time and rotations to maximize player ability and achieve success.

Assessment of step accuracy using the Consumer Technology Association standard.

The purpose of this study was to compare the accuracy of commercially-available physical activity devices when walking and running at various treadmill speeds using CTA 2056: Physical Activity Monitoring for Fitness Wearables: Step Counting, standard by the Consumer Technology Association (CTA). Twenty participants (10 males and 10 females) completed self-paced walking and running protocols on the treadmill for five minutes each. Eight devices (Apple iWatch series 1, Fitbit Surge, Garmin 235, Moto 360, Polar A360, Suunto Spartan Sport, Suunto Spartan Trainer, and TomTom Spark 3) were tested two at a time, one per wrist. Manual step counts were obtained from video to serve as the benchmark. The mean absolute percent error (MAPE) was calculated during walking and running. During walking, three devices: Fitbit Surge (11.20%), Suunto Sport (22.93%), and TomTom (10.11%) and during running, one device, Polar (10.66%), exceeded the CTA suggestion of a MAPE < 10%. The Moto 360 had the lowest MAPE of all devices for both walking and running. The devices tested had higher step accuracy with running than walking, except for the Polar. Overall, the Apple iWatch series 1, Moto 360, Garmin, and Suunto Spartan Trainer met the CTA standard for both walking and running.

Comparing Two Methods of Acute: Chronic Workload Calculations in Girls' Youth Volleyball.

Monitoring training load using acute:chronic workload ratio (ACWR) enables coaches to maximize fitness potential while mitigating injury risks by maintaining an optimal ACWR range. There are two methods of determining ACWR: rolling average (RA) and exponentially weighted moving average (EWMA). This study aimed to (1) compare weekly changes in kinetic energy (KE) output in female youth athletes (n = 24) during the high school (HSVB) and club volleyball (CVB) seasons and (2) evaluate the agreement in RA and EWMA ACWR calculations during the HSVB and CVB seasons. Weekly load was measured using a wearable device, and RA and EWMA ACWRs were calculated using KE. The HSVB data showed spikes in ACWR at the onset of the season and during one week mid-season (p = 0.001-0.015), but most weeks were in the optimal ACWR range. The CVB data had greater weekly variations throughout the season (p < 0.05), and many weeks were outside of the optimal ACWR range. There were moderate correlations between the two ACWR methods (HSVB: r = 0.756, p < 0.001; CVB: r = 0.646, p < 0.001). Both methods can be used as a monitoring tool for consistent training like that in HSVB, but more research is needed to investigate appropriate methods for an inconsistent season like that of CVB.

Salivary Cortisol Analysis in Collegiate Female Lacrosse Athletes.

Cortisol is a hormone that corresponds to physiological and emotional stress. The purpose of this study was to 1) evaluate the changes in cortisol in female Division I collegiate lacrosse players (n = 15) throughout the competitive season, and 2) evaluate the correlation between cortisol and athlete wellness and workload. Salivary cortisol samples were collected weekly in the morning throughout the entirety of the 2021 competitive season (12 weeks). Subjective athlete total wellness scores and sub-scores (muscle soreness, sleep quality, fatigue, and stress) were taken on the same days. Objective total weekly Athlete Load (AL, an amalgam workload metric) were tabulated from the previous training week. A significant effect of time was found on wellness (p < 0.001) and AL (p < 0.001) over the twelve weeks with weekly differences, such as weeks with more than one game, weeks with no games, weeks with students in quarantine (not competing), or weeks with academic stressors such as final exams. There were no weekly differences in cortisol (p = 0.058). Cortisol had negligible correlations with wellness (r = -0.010, p = 0.889) and AL (r = 0.083, p = 0.272) during the competitive season. These findings suggest that cortisol changed little for athletes throughout the season although training volume and wellness did. Thus, assessing acute responses of cortisol may prove to be more beneficial to evaluating athletes' stress.

Wellness Following Wins and Losses Based on Psychological Hardiness in Division I Women's Lacrosse.

Psychological hardiness encompasses three components: commitment, control, and challenge, and illustrates how individuals respond to stressors. Analyzing athletes' responses to wins and losses, depending on their psychological hardiness level, may provide insight of the impact of game outcome on student-athlete wellness. The purpose of this study was to examine postgame subjective wellness scores based on level of psychological hardiness following wins and losses in collegiate female lacrosse athletes. Players (n = 17) took the Dispositional Resilience Scale Scale-15 (DRS-15) at the start of the academic year and were grouped based on hardiness level: above average (AH) and below average (BA). Participants took a daily wellness survey rating their overall wellness, energy level, muscle soreness, stress level, and sleep quality. RM-ANOVA indicated no difference in post-game wellness scores between hardiness groups (Lambda(5,11) = 1.073, p = .426, ES = .328), by game outcome (Lambda(5,11) = 2.361, p = .109, ES = .518), or an interaction between hardiness and outcome of game (Lambda(5,11) = 1.421, p = .291, ES = .392). No hardiness group differences were found for overall wellness or sub-scores. These results show subjective wellness scores decrease collectively after a loss versus a win but refute prior studies as hardy players did not experience significantly less stress than their less hardy counterparts. Future studies should be conducted to assess wellness after differing game outcomes over many seasons to assist coaching staff on the subjective, psychological impacts of game.

Assessment of Relationships Between External Load Metrics and Game Performance in Women's Lacrosse.

The purpose of this study was to analyse the relationship between external load metrics with game performance for Division I collegiate female lacrosse. Data were collected using microtechnology during 26 games with 13 athletes (attackers n = 5, midfielders n = 8). External load variables included: total distance (TD), distance rate (DR), high-intensity (HI) distance, speed, HI sprints, accelerations, decelerations, metabolic equivalent distance (MED), and sprints. For attackers, goals, points, shots, and shots on goal (SOG) had low, positive associations with TD (r = 0.32 to 0.42) and MED (r = 0.39 to 0.45). For midfielders, goals, shots, and draw controls had low, positive relationships with TD (r = 0.34 to 0.41), DR (r = 0.33 to 0.45), and decelerations (r = 0.30 to 0.35). Points and SOG had low associations with TD (r = 0.35), DR (r = 0.33), accelerations (r = 0.31), and decelerations (r = 0.32 to 0.35). Turnovers demonstrated low, positive relationships with HI distance (r = 0.31) and HI sprints (r = 0.41). Though the correlations were low, they still revealed insights into workload metrics and offensive game statistics in the sport of lacrosse. Training for attackers should focus on agility and a training base for TD. Training for midfielders should focus on HI endurance and sprinting.

Assessment of accuracy of the Vacu-Med 17053 calibrator for ventilation, oxygen uptake (V(O(2))), and carbon dioxide production (V(CO(2))).

BACKGROUND: Few have examined the accuracy of mechanical calibrators used to calibrate metabolic monitors. OBJECTIVE: To evaluate the Vacu-Med 17053 motorized syringe calibrator for accuracy against the accepted standard method: the Douglas bag. METHODS: We tested oxygen consumption values (V(O(2))) of 522-3,210 mL/min. We mixed room air and calibration gases in the pumping syringes of the Vacu-Med 17053 and evacuated those gases into a Douglas bag, measured the Douglas bag volumes and concentrations, and converted to pulmonary ventilation, V(O(2)), and carbon dioxide production (V(CO(2))). RESULTS: The Vacu-Med 17053 calibrator overestimated V(O(2)) by a mean 28.6 mL/min (1.3% error), underestimated V(CO(2)) by 6.9 mL/min (-1.7% error), and underestimated pulmonary ventilation by 0.98 L/min (-1.4% error). The V(O(2)) and V(CO(2)) differences between the calibrator and the Douglas bag were larger at higher V(O(2)) levels. CONCLUSIONS: The V(O(2)) and V(CO(2)) differences might be attributable to fluctuations of the calibrator settings. The Vacu-Med 17053 calibrator was accurate with the application of a mathematical correction.

An Evaluation of Training Load Measures for Drills in Women's Collegiate Lacrosse.

PURPOSE: To statistically evaluate the internal and external load metrics in different types of lacrosse drills. METHODS: A total of 25 Division I collegiate female lacrosse players wore a heart rate monitor and a global positioning system during preseason training sessions. Seven measures determined training load, 2 internal measures and 5 external measures, across 5 different types of drills: stickwork, small-sided games, individual skills, conditioning, and team drills. Principal component analysis was used to determine which internal and external load variables were most associated with each drill type. RESULTS: Stickwork extracted 2 principal components, explaining 45% and 17% of the variance. Small-sided games extracted 1 principal component, explaining 51% of the variance. Individual skills extracted 2 components, explaining 39% and 22% of the variance. Conditioning extracted 2 components, explaining 44% and 24% of the variance. Team drills extracted 2 components, explaining 52% and 18% of the variance. CONCLUSIONS: In 4 out of 5 training modes, the inclusion of both internal and external training-load measures was necessary to accurately decipher training load. For most drills, the first component is related to measures of external load, and the second component described the balance between internal and external load measures. Small-sided games extracted only external measures including the following: accelerations, total distance, and average speed. These results show that a combination of internal and external load measures is required to determine training load during certain training modes. This information can help coaches make decisions about desired training load for practice sessions.

New Author Guidelines in Statistical Reporting: Embracing an Era Beyond p < .05.

Statistical reporting of quantitative research data has been plagued by potential bias and reporting suppression due to a single numerical output: the p-value. While there is great importance in its merit, creating a pass-fail system (set at point of .05) has created a culture of researchers submitting their project's data to a filing cabinet if it does not yield "statistical significance" based on this value. The editors of the International Journal of Exercise Science are following the American Statistical Association's call for statistical reform by adjusting our reporting guidelines to the following requirements: [1.] make an intentional effort to move away from statements "statistically significant" or "not significant;" [2] all p-values are to be reported in their raw, continuous form; [3.] measures of the magnitude of effect must be presented with all p-values; [4.] either an a-priori power analysis with relevant citations should be included or post-hoc power calculations should accompany p-values and measures of effect. The ultimate goal of this editorial is to join with other scholars to push the field toward transparency in reporting and critical, thoughtful evaluation of research.

Accuracy Assessment of a GPS Device for Maximum Sprint Speed.

Global positioning system (GPS) technology can capture maximum sprint speed (MSS) using fewer resources than electronic timing gates (ETG). Yet, errors with GPS technology are typically 1.01 km·hr-1 for instantaneous velocity, potentially limiting GPS accuracy. The purpose of this study was to compare MSS values obtained from GPS technology to those obtained from ETG. The MSS of 24 female athletes was determined using two tests that both began with a 20-m fly-in followed by: 1) 80-m maximal sprint with ETG placed at the start line, 30 m, 60 m, and 80 m, and 2) 30-m maximal sprint with ETG placed every 10 m. Sprint speed was calculated from each timing segment, and the fastest segment for each test was used for the calculated MSS. MSS was also obtained using a GPS unit measuring at 10 Hz. Mean bias and mean absolute percent error (MAPE) of the GPS was lower for the 80-m test (0.09 ± 1.24 km·hr-1, 3.5 ± 3.1%) than the 30-m test (1.58 ± 0.80 km·hr-1, 5.5 ± 2.6%). Lin's concordance agreement was found to be poor for both tests. The equivalence test indicated that the GPS was equivalent for both short and long distances, p < .05, meaning the two results were within a 5% equivalence interval. The GPS devices were within the acceptable range of accuracy at short (10-m) and long (30-m) distances. These results can guide coaching staff regarding how to test their athlete's metrics and the reliability of those results.

Acute ingestion of neuromuscular enhancement supplements do not improve power output, work capacity, and cognition.

BACKGROUND: Improving motor unit recruitment and function is trainable and positively affects performance. Evidence suggests that supplementation of choline, uridine, and docosahexaenoic acid (DHA) may also enhance neuromuscular function. The purpose of this study was to assess the influence of acute ingestion of these supplements on anaerobic exercise performance and cognition. METHODS: Twenty college-aged trained males (21.2±1.4 years, 181.2±6.1 cm, 94.4±20.5 kg, and 15.9±6.6% body fat) received the supplements (SUPP: 500 mg alpha glycerophosphocholine [AGPC], 250 mg uridine-5'-monophosphate, and 1500 mg DHA) or a placebo (PLA) in a randomized cross-over study design. All participants completed one familiarization and two experimental testing sessions, consisting of a warm up, vertical jump assessment, 61-kg bench press rep max, and completion of the ImPACT neural cognition test. In the two testing sessions, participants received, in random order, either the SUPP or a PLA, 90 minutes before testing. RESULTS: There was no significant difference between SUPP and PLA on exercise performance or neural cognition (P>0.05). CONCLUSIONS: The results of this study indicated no benefit from acute ingestion of a DHA, uridine, and choline supplement versus a placebo on anaerobic performance or cognition. It is likely that acute ingestion of these supplements did not provide the necessary elements to increase acetylcholine concentration or number of dendritic spines, rather ingestion for a longer time period and subsequent days may provide a benefit.

Current State of Commercial Wearable Technology in Physical Activity Monitoring 2015-2017.

Wearable physical activity trackers are a popular and useful method to collect biometric information at rest and during exercise. The purpose of this systematic review was to summarize recent findings of wearable devices for biometric information related to steps, heart rate, and caloric expenditure for several devices that hold a large portion of the market share. Searches were conducted in both PubMed and SPORTdiscus. Filters included: humans, within the last 5 years, English, full-text, and adult 19+ years. Manuscripts were retained if they included an exercise component of 5-min or greater and had 20 or more participants. A total of 10 articles were retained for this review. Overall, wearable devices tend to underestimate energy expenditure compared to criterion laboratory measures, however at higher intensities of activity energy expenditure is underestimated. All wrist and forearm devices had a tendency to underestimate heart rate, and this error was generally greater at higher exercise intensities and those that included greater arm movement. Heart rate measurement was also typically better at rest and while exercising on a cycle ergometer compared to exercise on a treadmill or elliptical machine. Step count was underestimated at slower walking speeds and in free-living conditions, but improved accuracy at faster speeds. The majority of the studies reviewed in the present manuscript employed different methods to assess validity and reliability of wearable technology, making it difficult to compare devices. Standardized protocols would provide guidance for researchers to evaluate research-grade devices as well as commercial devices used by the lay public.

Risk of Disordered Eating Among Division I Female College Athletes.

The purpose of this study was to assess the risk of disordered eating (DE) among female athletes in lean and non-lean sports using the ATHLETE survey. The ATHLETE survey is divided into six different constructs, and a high score indicates a high risk for DE. Eighty-three varsity female athletes from eight Campbell University sports teams completed the survey and a medical history form anonymously. The sports were divided into sports that traditionally have a high risk for DE (lean sports) and those with a low risk (non-lean sports). The lean sports included: cheerleading, cross country/track and field, swimming, and volleyball. The non-lean sports included: basketball, golf, soccer, and softball. The total mean score of the ATHLETE survey for the lean sports was 100.1 ± 17.4, compared to the non-lean sports scoring 90.1 ± 16.9, p = 0.011. The two constructs that showed significant difference between lean and non-lean sports were Social Pressure on Body Shape (lean: 12.2 ± 3.9, non-lean: 9.4 ± 4.6, p = 0.005) and Team Trust (lean: 7.4 ± 3.3, non-lean: 5.6 ± 2.2, p = 0.004). The results indicate that lean sports exhibited a higher risk for development of DE compared to athletes participating in non-lean sports. It appears that the primary influence of DE in these female athletes came from external social pressures that may therefore dictate their exercise and nutritional habits.

Protein and Amino Acid Supplementation Does Not Alter Proteolytic Gene Expression following Immobilization.

Objective. To determine if supplementation of protein and amino acids (PAA) decreases skeletal muscle expression of atrophy-related genes, muscle mass, and strength during immobilization in humans. Methods. Twenty males wore a lower-limb immobilization boot for 28 days and consumed either a PAA supplement (28 g protein) or carbohydrate placebo (28 g maltodextrose), while consuming their normal daily diet. Testing sessions included dietary analysis, lower-leg girth and body composition measurements, strength testing, and gastrocnemius muscle biopsies. Muscle was analyzed for mRNA expression of markers in the ubiquitin and calpain systems, myostatin, TNF-α, and NF-κB. Results. All genes of interest increased over time (P < .05), but there was no difference between groups. Lower-leg girth decreased over time (P = 0.02); however, there were no significant changes in body composition or strength. Conclusion. Short-term lower-limb disuse, despite the absence of significant muscle atrophy, is associated with increases in skeletal muscle gene expression of several proteolysis-related genes. These changes do not appear to be altered by oral PAA supplementation.