Heart Rate Zones Research Articles

Physiological and Perceptual Recovery-Stress Responses to an Elite Netball Tournament.

To investigate and explore the relationships between physiological and perceptual recovery and stress responses to elite netball tournament workloads. Nine elite female netballers were observed across a 3-day (T1-3), 4-match tournament. Participants provided salivary samples for cortisol and alpha-amylase analysis, completed the Short Recovery Stress Scale (SRSS), and reported session ratings of perceived exertion. Inertial measurement units and heart-rate monitors determined player load, changes of direction (COD), summated heart-rate zones, and jumps. Analysis revealed 6 significant SRSS time effects: (1)decreased recovery markers of physical performance (P = .042), emotional balance (P = .034), and overall recovery (P = .001) and (2)increased perceptual stress markers of muscular stress (P = .001), negative emotional state (P = .026), and overall stress (P = .010). Salivary cortisol decreased over the tournament (T1-3) before progressively increasing posttournament with greater salivary samples for cortisol on T+2 compared with T3 (P = .014, ES = -1.29; -2.24 to -0.22]) and T+1 (P = .031, ES = -1.54; -2.51 to -0.42). SRSS overall recovery moderately negatively correlated with COD (r = -.41, P = .028) and session ratings of perceived exertion (r = -.40, P = .034). Cumulative workload did not relate to posttournament perceptual or salivary responses. Percentage change in salivary variables related (P < .05) to total player load, total COD, and overall recovery across specific cumulative time periods. During and after an elite netball tournament, athletes indicated increased perceptual stress and lack of recovery. The SRSS is a valuable tool for recovery-stress monitoring in elite tournament netball. It is recommended that practitioners monitor COD due to its negative influence on perceived overall recovery.

Effect of training at intensities around critical velocity on 400 meters front crawl performance in young swimmers.

Young swimmers are rarely involved in training control, leading to inadequate volume and prescription of training intensities. This study aimed to examine the effect of prescribing and monitoring training intensities around critical velocity (CV) on 400 m front-crawl performance during an 8-weeks period. Twenty young male swimmers (13.4±1.0 years) were randomly assigned into two groups. The experimental group (EG) used training monitoring based on intensities around CV (95, 100, 105 and 110% of CV), while for the control group (CG) different heart rate (HR) zones (EN1+, EN2, EN2+ and EN3) were used as an intensity criterion. The training volume was the same for both EG and CG. A maximal 400 m front-crawl test was performed before and after the 8-week period to determine CV intensities and to assess alternations in performance. The rate of perceived exertion (RPE) and HR values were also evaluated. Significant main effects of time were observed for T400, CV, HR and RPE. A significant group × time interaction was found for T400 (P=0.035, effect size = 1.07, moderate). Results revealed significant pre-to-postimprovements for both EG (from 328.46±26.25 to 305.88±20.09) and CG (from 329.07±25.24 to 314.75±19.87). A significant group × time interaction was also found for CV (P=0.005, effect size=1.51, large). Results revealed significant pre- to post improvements for both EG (from 1.126±0.08 to 1.207±0.07) and CG (from 1.124±0.08 to 1.173±0.07). Both training methods induced significant improvements in 400 m front-crawl performance with a greater degree for the training prescription and monitoring using CV intensities.

Cardiac Rehabilitation Based on the Walking Test and Telerehabilitation Improved Cardiorespiratory Fitness in People Diagnosed with Coronary Heart Disease during the COVID-19 Pandemic.

This study investigated an alternative home-based cardiac telerehabilitation model in consideration of the recommendations for the COVID-19 quarantine of people diagnosed with coronary heart disease (CHD). We hypothesized that using a 200 m fast walking test (200 mFWT) and telerehabilitation would create an effective alternative cardiac rehabilitation (CR) intervention that could improve cardiorespiratory fitness. Participants (n = 19, mean age 60.4 ± 9.6) of the 8-week intervention performed regular physical exercise at the target heart rate zone determined by calculations based on the 200 mFWT results. In our study, the participants were supervised using telerehabilitation. A total of 84% of participants completed the 8-week intervention. No adverse events were reported during telerehabilitation. The study participants noted a significant improvement (p < 0.001) in cardiorespiratory fitness expressed by an 8% reduction in the walking test time (Δ 8.8 ± 5.9 s). Home-based telerehabilitation based on 200 mFWT effectively increased the cardiorespiratory fitness in people with CHD with a low to moderate cardiovascular risk. This was a novel approach in CR during the COVID-19 pandemic. As research in this area is justified, this paper may serve as an alternative method of providing healthcare during the COVID-19 pandemic and as a basis for further upcoming randomized controlled trials.

Exercise Intensity during Olympic-Distance Triathlon in Well-Trained Age-Group Athletes: An Observational Study

The aim of this study was to examine the exercise intensity during the swimming, cycling, and running legs of nondraft legal, Olympic-distance triathlons in well-trained, age-group triathletes. Seventeen male triathletes completed incremental swimming, cycling, and running tests to exhaustion. Heart rate (HR) and workload corresponding to aerobic and anaerobic thresholds, maximal workloads, and maximal HR (HRmax) in each exercise mode were analyzed. HR and workload were monitored throughout the race. The intensity distributions in three HR zones for each discipline and five workload zones in cycling and running were quantified. The subjects were then assigned to a fast or slow group based on the total race time (range, 2 h 07 min–2 h 41 min). The mean percentages of HRmax in the swimming, cycling, and running legs were 89.8% ± 3.7%, 91.1% ± 4.4%, and 90.7% ± 5.1%, respectively, for all participants. The mean percentage of HRmax and intensity distributions during the swimming and cycling legs were similar between groups. In the running leg, the faster group spent relatively more time above HR at anaerobic threshold (AnT) and between workload at AnT and maximal workload. In conclusion, well-trained male triathletes performed at very high intensity throughout a nondraft legal, Olympic-distance triathlon race, and sustaining higher intensity during running might play a role in the success of these athletes.

400 meters freestyle pacing strategy and race pace training in age-group swimmers

This study aimed to characterize the 400 m freestyle pacing strategy, the effect of post-race feedback, and individualised race-pace training. Twenty male swimmers (13.4 ± 1.0 years) were randomly assigned into two groups. The experimental group used training monitoring based on intensities around 400 m pace (92 and 97% of 400 m speed), while, for the control group different heart rate zones (EN2 and EN2+) were used as an intensity criterion. The training volume was the same for both groups. A maximal 400 m freestyle simulated competition was performed before and after the 3 weeks period to determine intensities and to assess changes in performance. The rate of perceived exertion and heart rate values were also evaluated. A fast start in the first 50-100 m, then a constant speed in the middle of the race and an end-spurt during the last 50-100 m was the pacing pattern adopted by the majority of the swimmers. Significant main effects of time were observed for 400 m time ( p = 0.001; ES 3.39; very large). Results revealed significant pre-to-post improvements from 328 ± 26.3 s to 317 ± 19.4 s in the experimental group and from 329 ± 25.2 s to 321 ± 21.1 s in the control group. All the swimmers adopted almost the same parabolic pacing strategy before and after the training program with some differences in seconds that have made the strategy of the experimental group better balanced during the post-training test. Both training methods induced significant improvements in 400 m performance, to a greater extent for the training using intensities near 400 m race pace.

Official matches and training sessions: physiological demands of elite junior badminton players

Aim: To evaluate the intensity of training and official badminton matches (international championship) in junior elite players. Methods: Twelve elite players from the Brazilian junior national team (6 male and 6 female) were monitored during 19 training sessions and 50 official men's and women's single and double matches in the XXVII Pan-American Junior Games. Subjects underwent an incremental running step test to determine maximal oxygen uptake (VO2max), and an individual relationship between heart rate (HR) and VO2max was established to estimate exercise intensity and oxygen uptake at official matches (OMs) and training sessions. HR was monitored during multi-shuttlecock (MS), technical-tactical (TT), and physical (PS) training methods, as well as during simulated matches (SMs) and OMs. Variables such as %HRmax, HR zones, %VO2max, and energy expenditure were also calculated. Results: OM was the most intense activity monitored for male and female athletes, followed by SM according to %HRmax (86.8 ± 4.1% and 84.4 ± 5.0% for female and male, respectively, in OM vs. 74.6 ± 2.3% and 75.0 ± 5.0% for female and male, respectively, in SM). OM mean energy expenditure was 10.7 ± 0.5 kcal.min-1 for females and 14.9 ± 4.6 kcal.min−1 for males. Conclusion: MS training has less physiological demand and OM presented higher intensity. SM, on the other hand, had the closest physiological demand to an OM.

Usefulness of Linear Mixed-Effects Models to Assess the Relationship between Objective and Subjective Internal Load in Team Sports.

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.

Variation in Heart-Rate Profile During a Prolonged, Submaximal Swim Bout.

To describe the heart-rate (HR) response during a prolonged, submaximal, multirepetition swimming bout (ie,typical early-season swimming training), as there is currently little or no literature on this topic. A total of 12 collegiate swimmers were instructed to complete sixty 91.4-m (100-yd) freestyle repetitions at their fastest sustainable pace, allowing between 5 and 10 seconds of rest between repetitions. Each swimmer was outfitted with a cardiotachometer, which monitored HR throughout the trial. Completion time (CT) was also recorded for each repetition. Individual means of HR and CT were calculated, and linear mixed models were used to determine the trend across repetitions and between- and within-subject SD for HR and CT. The mean (SD) value for HR was 167.8 (10.8) beats per minute (bpm), for CT was 68.7 (4.1) seconds, and for percentage of best time was 71.2% (4.5%). There was no change (Δ rep 55-6) in HR (-0.1bpm; 95% confidence interval, -6.8 to 6.6bpm; P = .97), whereas CT increased (3.0 s; 95% confidence interval, 1.5-4.4 s; P = .001). The between-subjects SD (95% confidence interval) for HR was 12.6 (8.4-19.3bpm) and for CT was 4.6 (3.1-7.0s). The within-subject SDs for HR and CT were 4.0 (3.8-4.3bpm) and 0.9 (0.8-0.95s), respectively. The inherent individual variability between swimmers in HR during training suggests that coaches carefully consider the common practice of prescribing workout intensity using rigid HR zones.

The Relationships between Internal and External Load Measures for Division I College Football Practice.

The aim of this study is to explore the relationships between internal and external load measures in American football. Thirty football players wore a portable integrated monitor unit for 10 weeks during the fall football season. Relationships between internal and external load measurements were determined. Internal load consisted of heart rate zones and heart rate-derived measures and session Ratings of Perceived Exertion (sRPE). External load consisted of distance in different speed zones, total distance traveled, and accelerations. There were many significant positive relationships, but the meaningful relationships (r > 0.5) were between heart rate-derived measures of load (Training Impulse and heart rate reserve) and low-intensity movement and total distance. Only accelerations between 1 and 1.99 m·s−2 were moderately correlated to heart rate-derived internal load. RPE values alone did not correlate strong enough with any of the measure but sRPE training load (sRPE-TL) correlated to most external values. Overall, moderate correlations were present between heart rate-derived internal load to total distance and lower intensity movement. sRPE-TL values had high correlations but were highly dependent on duration, not perceived exertion. When addressing load in American football, duration of the session is a key component in determining internal load as HR data and sRPE alone do not correlate highly with external loads.

Defensive Strategy and Player Sex Impact Heart-Rate Responses During Games-Based Drills in Professional Basketball.

Games-based drills (GBD) are the predominant form of training stimulus prescribed to male and female basketball players. Despite being readily manipulated during GBD, the impact of defensive strategy on the sex-specific demands of GBD remains unknown. Therefore, the aim of this study was to quantify and compare the heart-rate (HR) responses experienced during 5v5 GBD using different defensive strategies (man-to-man defense vs zone defense [ZD] formations) according to player sex. HR was recorded in 11 professional male and 10 professional female basketball players while performing 5v5 GBD with different defensive strategies (man-to-man defense or ZD). HR-based training load was also calculated using the summated heart-rate zones model. During man-to-man defense, mean HR (ηp2=.02), relative time (in percentage) spent working at 90% to 100% maximal HR (ηp2=.03), and summated heart-rate zones (ηp2=.02) were greater (P < .05) in female players compared with males. During ZD, higher (P < .01) peak HR (ηp2=.07), mean HR (ηp2=.11), relative and absolute (in minutes) time spent working at 80% to 89% maximal HR (ηp2=.03 and .03, respectively) and 90% to 100% maximal HR (ηp2=.12 and .09, respectively), and summated heart-rate zones (ηp2=.19) were observed in female players compared with males. The defensive strategy employed during 5v5 full-court GBD influences HR responses and training load differently according to sex, where female players experience higher HR responses than males, especially when ZD are adopted. Basketball coaching staff can use these findings for the precise manipulation of team defenses during GBD to elicit desired cardiovascular stress on players.

ACUTE EFFECT OF AEROBIC EXERCISE OF DIFFERENT INTENSITIES IN CYTOKINES OF UNIVERSITY STUDENTS

ABSTRACT Introduction: A single exercise training session promotes stimuli for changes in the immune system that are cumulatively considered adaptations to the exercise. Objective: This paper explores the acute effect of different intensities of aerobic exercise on anti-inflammatory and proinflammatory markers in apparently healthy university students. Methods: Eighteen volunteers underwent two sessions of aerobic exercise, the first at 65-70% estimated heart rate (HR), and after seven days, a second session at 80-85% HR. Before and after each session, venous blood was drawn, in order to analyze interleukin (IL) 6 and 10 in a Milliplex Kit. The participants’ level of physical activity was determined using a questionnaire. For statistical comparisons, two-way ANOVA was used for the variables hemodynamics and perceived exertion. The cytokine results were compared through the Student's t-test for repeated measurements. The exclusion criteria were the practice of physical exercise and having drunk alcohol on the day before the intervention sessions, the presence of osteomioarticular conditions, and missing one of the sessions. Results: This study showed that IL-6 was not significantly decreased when comparing the two sessions. IL-10 was significantly decreased (p=0.033) in the 65-70% HR session but not in the 80-85% HR session. The delta variation for IL-10 showed a tendency (p=0.053) towards a greater decrease in the 65-70% HR session when compared to the 80-85% HR session. There were no differences in the acute effect of exercise when comparing the levels of physical activity. Conclusion: This study highlights that two different zones of high intensity exercise can induce different inflammatory responses, as demonstrated by the significant decrease in IL-10 in the 65-70%HR zone. The study also shows that there was no difference in physical exercise response in individuals with moderate and high physical activity levels. Level of evidence III; Comparative study.

The Influence of Aerobic Fitness on Heart Rate Responses of Custody Assistant Recruits during Circuit Training Sessions.

This study captured heart rate (HR) responses of custody assistant (CA) recruits undertaking circuit training sessions. Data from 10 male and 12 female CA recruits were analyzed. Based on YMCA step test recovery HR, recruits were divided into higher fitness (HF; top 25%), lower fitness (LF; bottom 25%), and moderate fitness (MF; remaining recruits) groups. HR was measured during two circuit training sessions featuring calisthenics and running. HR zones were defined as: very light (<57% of age-predicted maximum heart-rate [HRmax]); light (57–63% HRmax); moderate (64–76% HRmax); vigorous (77–95% HRmax); and very vigorous (>95% HRmax). A one-way ANOVA, with Bonferroni post hoc, calculated between-group differences in time spent, and percentage of total time, in the HR zones. In session one, the LF group spent less time in the light training zone compared to the MF group, and more time in the very vigorous zone compared to the HF group (p = 0.027–0.047). In session two, the LF group spent more time in the moderate zone compared to both groups, and a greater percentage of time in the very vigorous zone compared to the MF group (p = 0.002–0.004). LF recruits generally worked harder during circuit training than their fitter counterparts, which supported recommendations for ability-based modifications.

Factors Influencing the Impact of Depressive Symptoms on Physical Functional Capacity After Cardiac Rehabilitation.

Purpose This study aims to determine (1) if depressive symptoms in the year following completion of cardiac rehabilitation impact physical functional capacity and (2) if exercise, perceived benefits and barriers, self-efficacy, and social support moderate this relationship. Design This longitudinal correlational secondary data analysis included 379 cardiovascular rehabilitation patients. Methods Participants completed measures of depression and potential moderating variables at baseline, 2 months, 6 months, and 12 months and 6-minute work test at baseline and 12 months and wore heart rate monitors to measure exercise for 12 months. Findings Poorer physical functional capacity was predicted by depressed mood score. This relationship was moderated by the percentage of time exercising in target heart rate zone and family support of exercise, but not by perceived benefits and barriers or self-efficacy for exercise. Conclusions Depressive symptoms negatively impact physical functional capacity, and this relationship is moderated by family support and the percentage of time exercising in target heart rate zone. Clinical relevance Improving percentage of time exercising in target heart rate zone may be a mechanism by which patients with depressed mood can optimize physical functional capacity.

Effects of the Intensity of Lifestyle Exercise on Changes in Blood Pressure.

The purpose of this study was to investigate whether the amount of time participants exercised in the target heart rate zone (THRZ) influenced change in blood pressure (BP) one year following a cardiac event. Lifestyle exercise (habitual, small exercise opportunities) and intensity were objectively measured using portable heart rate monitors. Linear mixed models were used to analyze change in BP among 331 participants. Mean BP at baseline was 118/70 mmHg, and both systolic and diastolic BP increased from baseline to one year-4.79 mmHg (p <.001) and 2.09 mmHg (p =.002), respectively. Overall, participants had a decrease in levels of lifestyle exercise. After controlling for time, age, gender, and study group, SBP change was inversely associated with amount of time in THRZ. Given suboptimal engagement in recommended exercise, the underlying mechanisms of lifestyle exercise effects on the time spent in THRZ to reduce BP warrants further study in this population.

Workload and well-being across games played on consecutive days during in-season phase in basketball players.

This study aimed to quantify and compare workload and well-being across basketball games played on consecutive days during the in-season phase. Seven players (mean [SD]: age, 20.8 [1.6] y; stature, 195.0 [5.4] cm; body mass, 88.3 [4.2] kg; training experience, 11.6 [3.7] y) competing in the second-tier Lithuanian league were recruited. Changes in workload and well-being were monitored across six NKL games in three separate weeks during the in-season phase, with two games per week played on Friday (Day 1) and Saturday (Day 2). External workload was determined as PlayerLoad (PL) and PL per minute (PL/min) via microsensors. Internal workload was determined as percentage of maximum heart rate (%HRmax), summated heart rate zones (SHRZ) workload, and session-rating of perceived exertion (sRPE) workload. Well-being was evaluated using questionnaires assessing fatigue, sleep quality, general muscle soreness, stress levels and mood. Linear mixed models and effect size analyses were used to compare workload and well-being between Day 1 and Day 2. Significantly lower PL/min (P=0.029; ES=0.26, small), greater perception of fatigue (P<0.001; ES=1.31, large) and lower total well-being score (P<0.001; ES=0.59, small) were observed for basketball games played on Day 2 compared to games played on Day 1. Two games played on consecutive days elicited similar game workloads with higher perceived fatigue and lower well-being in the second game day. These findings suggest basketball coaches using recovery strategies to optimize player well-being during congested game schedules.

Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise.

ABSTRACTPurposeThis study assessed how individuals compensate for energy expended during a 12-wk aerobic exercise intervention, elucidating potential mechanisms and the role exercise dose plays in the compensatory response.Participants and DesignThree-arm, randomized controlled trial among sedentary adults age 18 to 40 yr, body mass index of 25 to 35. Groups included six exercise sessions per week, two sessions per week, and sedentary control.MethodsRate of exercise energy expenditure was calculated from a graded exercise test averaged across five heart rate zones. Energy compensation was calculated as the difference between expected weight loss (based on exercise energy expenditure) and changes in fat and fat-free mass (DXA). Resting energy expenditure was assessed via indirect calorimetry and concentrations of acylated ghrelin, leptin, insulin, and Glucagon-like peptide 1 (GLP-1) were assessed fasting and postprandial (six timepoints over 2 h).ResultsThe 6-d·wk−1 group expended more energy (2753.5 kcal) and exercised longer (320.5 min) per week than the 2-d·wk−1 group (1490.7 kcal, 1888.8 min, P < 0.05), resulting in greater fat loss compared with the 2-d or control groups (P < 0.05). Exercise groups did not differ in the % or total kcal compensated. Greater decreases in area under the curve (AUC) for acylated ghrelin predicted greater fat loss, regardless of group, energy expended per week, exercise duration, or exercise intensity. Changes in leptin AUC was the only independent predictor for energy compensation, with a greater decrease in leptin AUC predicting less energy compensation. Exercise frequency, energy expended, duration, or intensity did not influence energy compensation.ConclusionsLeptin is an important factor in successful weight loss through exercise, with greater postprandial decreases promoting less compensation. Greater amounts of exercise do not influence the compensatory response to an exercise-induced energy deficit.

Workload Differences Between Training Drills and Competition in Elite Netball.

To examinepotential differences in internal and external workload variables between playing positions and between training drills and games within an elite netball team during training and competition. Nine elitefemale netballers were monitored during 15 games and all training sessions over 28 weeks. Workload variables assessed were relative PlayerLoad (PL per minute), accelerations, decelerations, jumps, changes of direction, high-intensity events, medium-intensity events, low-intensity events, PL in a forward direction, PL in a sideways direction, PL in a vertical direction, and summated heart-rate zones using heart-rate monitors and inertial measurement units. Conditioning and match play during training were the only drills that matched or exceeded game workloads. Workloads during small-sided games were lower than game workloads for all variables. In games, goalkeeper, goal attack, and goal shooter had a greater frequency of jumps compared with other positions. Midcourt positions had a greater frequency of low-intensity events in a game. Workloads during small-sided games were lower than game workloads across all external and internal variables; therefore, netball staff should modify these small-sided games if they wish them to develop game-based qualities. Specific game workload variables indicate that there are differences within some positional groups; coaches need to be aware that positional groupings may fail to account for differences in workload between individual playing positions.

Abstract A17: An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor

Abstract Introduction: Regular physical activity (PA) lowers the risk of endometrial, breast, and colorectal cancer. However, nearly half of American adults are not sufficiently active. The physical inactivity rate is even higher among the overweight and obese population, which, in combination with the unfavorable effect of excess body weight, puts this population at a greater risk for cancer. Advancements in wearable sensor technology provide opportunities for personalized approaches to increase motivation to be active. The current pilot study used continuous glucose monitors (CGM) to demonstrate the immediate, physiologic benefits of PA. Methods: Insufficiently active (&amp;lt;150 mins of moderate intensity PA per week) overweight and obese (body mass index &amp;gt;= 25 kg/m2) adults (18-65 years old) without diabetes are being recruited to participate in this pilot intervention. Upon enrollment, participants go through a one-on-one PA education session that includes a discussion about the health benefits of recommended PA levels, demonstration of the acute effect of PA on daily glucose patterns using a web-based glucose simulator, calculation of personal heart rate zones for moderate intensity PA, and development of an exercise plan. After the education session, participants are given a Fitbit Alta HR wristband and are instructed to wear it over the next 10 days. Participants are also given a Freestyle Libre CGM, which consists of a sensor and a reader. The sensor is inserted into the back of the upper arm to collect interstitial glucose data every 15 minutes for 10 days after activation. The reader displays current glucose readings and a graph of the 8 previous hours of glucose data upon scanning the sensor. Participants are instructed to scan the sensor at least 4 times a day and are encouraged to achieve at least 150 minutes of moderate-intensity PA each week. At the end of the self-monitoring period, participants return their Fitbit and have their CGM sensor removed. Results: Thus far, 10 of 20 participants have enrolled in and completed the study. These participants have been 100% female, 70% obese, and 20% Hispanic with a mean age of 41.5 (SD = 8.6) years old. On average, participants scanned their sensor 6 times each day and wore the Fitbit for all 10 days. On average, participants highly rated each component of the education session (on a 5-point scale) for improving their PA knowledge (mean = 4.4), increasing their PA motivation (mean = 4.4), and providing personally relevant information (mean = 4.6). Participants also reported a very positive experience wearing the CGM, with mean ratings (on a 5-point scale) of 4.8 for usability, 4.6 for convenience, 4.9 for value, 4.9 for relevance, and 4.7 for motivating. Conclusion: These preliminary data suggest that using a CGM to motivate PA among nondiabetic adults is feasible and acceptable. Future research will be conducted to examine the effect a CGM-based PA intervention has on changing PA behavior. Citation Format: Yue Liao, Christopher J. Miller, Diana L. Urbauer, Therese B. Bevers, Ernest Hawk, Karen M. Basen-Engquist, Susan M. Schembre. An innovative physical activity intervention in overweight and obese adults using continuous glucose monitor [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A17.

Losing Sleep Over It: Sleep in Basketball Players Affected by Game But Not Training Workloads.

To examine the impact of workload volume during training sessions and games on subsequent sleep duration and sleep quality in basketball players. Seven semiprofessional male basketball players were monitored across preseason and in-season phases to determine training session and game workloads, sleep duration, and sleep quality. Training and game data were collected via accelerometers, heart-rate monitors, and rating of perceived exertion (RPE) and reported as PlayerLoad™ (PL), summated heart-rate zones, and session RPE (sRPE). Sleep duration and sleep quality were measured using wrist-worn activity monitors in conjunction with self-report sleep diaries. For daily training sessions and games, all workload data were independently sorted into tertiles representing low, medium, and high workload volumes. Sleep measures following low, medium, and high workloads and control nights (no training/games) were compared using linear mixed models. Sleep onset time was significantly later following medium and high PL and sRPE game workloads compared with control nights (P < .05). Sleep onset time was significantly later following low, medium, and high summated heart-rate-zones game workloads, compared with control nights (P < .05). Time in bed and sleep duration were significantly shorter following high PL and sRPE game workloads compared with control nights (P < .05). Following low, medium, and high training workloads, sleep duration and quality were similar to control nights (P > .05). Following high PL and sRPE game workloads, basketball practitioners should consider strategies that facilitate longer time in bed, such as napping and/or adjusting travel or training schedules the following day.

Shuttle Run And Performance In Aerobic And Anaerobic Capacities.

Field hockey is a physiologically demanding sport with intermittent bouts of aerobic and anaerobic performance. The ability to assess player condition is vital to coaching success. In place of VO2,the 20-meter shuttle run test (SRT) is a common alternative for on field determination of a player's aerobic fitness. Limited data supports the relationship between shuttle run and anaerobic fitness in this population. PURPOSE: To determine the accuracy of a shuttle run test (SRT) as a predictor of field hockey performance. METHODS: We enrolled19 D1 field hockey players (18-22 years old) in an 11-week prospective study. Goalies and injured players were excluded from the study. A 6-week program prior to the study consisted of a 20m shuttle run during practice. Speed was gradually increased by 0.5 km/h at a time, each increase in running speed was coded as a change in level. A Polar Pro GPS/heart rate recorder (Polar Electro Inc. Bethpage, NY) recorded effort parameters during 43 practices. Data included time in heart rate (HR) zone 4 (80-89%) (sec), time in HR zone 5 (90-100%) (sec), percentage of HR max (%) total distance covered (m), distance/min (m/min), maximum speed (km/h), number of sprints (acceleration >1.9 m/s2), and distance in speed zone 5 (>19.00 km/h) (m). Bivariate correlations and linear regressions tested relationships between SRT and on-field performance. RESULTS: SRT was significantly related to total distance covered (r=0.090, p=0.022), distance per minute (r=0.112, p=0.004), maximum speed (r=0.097, p=0.013), distance in speed zone 5 (r=0.119, p=0.002), and number of sprints (r=0.188, p<0.001). No other relationships were detected. Better performance on the SRT corresponded to more (and more frequent) in-practice sprinting. CONCLUSION: Although the SRT may not provide a valid estimate of VO2 max, it is a valid predictor for many components of on-field performance. It associates with total distance, distance per minute, maximum speed, distance in speed zone 5, and number of sprints in collegiate field hockey players.