Variability of Competition-Based Caloric Expenditure and Relative Heart Rates in National Collegiate Athletic Association Division I Women's Basketball.

ABSTRACT: Sanders, GJ, Boos, B, Rhodes, J, Peacock, CA, Kollock, RO, and Scheadler, CM. Variability of competition-based caloric expenditure and relative heart rates in National Collegiate Athletic Association Division I women's basketball. J Strength Cond Res 36(1): 162-166, 2022-Basketball athletes frequently engage in high intensities (≥85% HRpeak) throughout competition, and it is unknown how high-intensity play coincides with caloric expenditure and average and peak relative heart rates. The purpose of the study was to assess caloric expenditure throughout 31 games (4- to 10-minute quarters) in National Collegiate Athletic Association Division I women's basketball. A total of 11 female athletes were tested for peak heart rate (HRpeak) and peak oxygen uptake (V̇o2peak) before the season, then monitored in-season with heart rate-based wearable devices. Estimated caloric expenditure, average (% HRavg) and peak (% HRpeak) relative heart rates, time played at intensities ≥85% HRpeak, and live time (i.e., game minutes not including stoppages in play) were recorded each game. Data were assessed as a team and compared across 4 quarters, and then, interathlete comparisons were made based on full game data. There were significant main effects of 10-minute quarters on calories (p < 0.001) and % HRavg (p = 0.015) but not playing intensity ≥85% HRpeak (p = 0.125) and % HRpeak (p = 0.629). Caloric expenditure was the only variable to increase from the first to the fourth quarter. There were main effects of individual athletes on calories, % HRavg, % HRpeak, live time, and playing intensity ≥85% HRpeak (p < 0.001 for all). Assessing individual athletes, relative to a team assessment across quarters, can provide practitioners with more accurate caloric expenditure, heart rate, and playing intensity data per athlete to improve training and fueling protocols.

Competition-Based Heart Rate, Training Load, and Time Played Above 85% Peak Heart Rate in NCAA Division I Women's Basketball.

ABSTRACT: Sanders, GJ, Boos, B, Rhodes, J, Kollock, RO, and Peacock, CA. Competition-based heart rate, training load, and time played above 85% peak heart rate in NCAA division I women's basketball. J Strength Cond Res 35(4): 1095-1102, 2021-Basketball athletes frequently engage in intensities ≥85% HRpeak throughout competition. Knowing the time spent competing at intensities ≥85% HRpeak can improve training protocols. The purpose of the study was to assess heart rate responses across 4-quarter games (N = 31) in an NCAA Division I women's basketball season. Ten female athletes were tested and monitored with heart rate-based wearable microsensor devices. Before the season, HRpeak was recorded through a peak metabolic test (V̇o2peak). Average (HRavg) and HRpeak were recorded for each game, and time spent in 5 heart rate zones (HRZones) were recorded: HRZone1 = 50-60% HRpeak, HRZone2 = 60-70% HRpeak, HRZone3 = 70-76% HRpeak, HRZone4 = 77-84% HRpeak, and HRZone5 = 85-100% HRpeak. Training load was calculated with the summated-heart-rate-zone model (SHRZmod). There was a main effect of position (p ≤ 0.019) and quarter (p ≤ 0.005) on SHRZmod and on time spent in HRZone1-5. Athletes accumulated the most time in HRZone4 and HRZone5 and in the fourth quarter, and SHRZmod was the greatest in the fourth quarter. There was no main effect for HRavg and HRpeak (p ≥ 0.110). Athletes averaged 34.5 minutes per game competing in HRZone5 or ≥85% HRpeak with nearly one-third of those minutes accumulated in the fourth quarter. Although there were no differences in HRavg and HRpeak from quarter to quarter, SHRZmod increased from the first to fourth quarter. Utilizing time spent in heart rate zones and training load with SHRZmod can provide valuable information to practitioners regarding the intensity and physiological demands of competitive basketball games.

Factors associated with minimal changes in countermovement jump performance throughout a competitive division I collegiate basketball season.

The purpose of the study was to assess factors that contribute to countermovement jump (CMJ) performance in women's basketball athletes. Thirteen female athletes participated and were tested for maximal oxygen uptake (VO2max) and heart rate (HRmax). Athletes were monitored, daily for a total of 21 weeks with heart rate-based wearable devices and CMJ performance and body weight were tested weekly after one day of recovery. 3-jump average height (CMJavg), maximum height jump (CMJmax), and CMJ power (Watts) were calculated and recorded. Playing intensities >85% HRmax, HRavg, HRmax and training load were averaged for three consecutive days prior to the recovery day. After the season, data was grouped as changes in CMJ power from week one: Large (≤ -4.39% change), Moderate (-4.4% to -0.62% change), and Minimal (≥ -0.61% change) changes. Fixed-effects models revealed a main effect of group (p ≤ 0.05) for CMJavg, CMJmax, VO2max, weekly percent changes in body weight and for 3-day training load, HRavg, and playing time at >85% HRmax. When athletes experienced minimal changes in CMJ performance, relative to large changes, they produced greater power, jumped higher, avoided negative changes in weekly body weight, had a greater preseason VO2max and 3-day average workloads appeared to have an impact on CMJ performance.

Bilateral Asymmetries in Ultrasound Assessments of the Rectus Femoris throughout an NCAA Division I Volleyball Preseason.

The purpose of the study was to assess glycogen content of the rectus femoris (RF) muscles utilizing high-frequency ultrasound throughout an intensive, nine-day preseason training period in NCAA division I volleyball athletes. In the morning prior to the beginning of practice, athletes (n = 13) left and right RF muscles were assessed via ultrasound to quantify muscle fuel ratings (0⁻100 score range). The recommended location of the RF ultrasound scans were based on manufacturer guidelines, and the same technician recorded the daily measurements. To assess daily training load, session ratings of perceived exertion (s-RPE) were utilized. A paired t-test revealed a large significant difference between left (51.7 ± 17.9) and right (32.8 ± 17.4) RF muscle fuel ratings (p < 0.001). There was also a major effect of time on s-RPE (p < 0.001) and left (dominant) RF fuel rating (p = 0.001). s-RPE decreased from the beginning to the end of the training camp. However, left RF fuel ratings increased from the first to the second day, then remained elevated all throughout the preseason. In conclusion, all athletes were left-leg dominant and had a 57.6% bilateral asymmetry between their left and right RF muscle fuel ratings despite changes in training load. High-frequency ultrasounds are a noninvasive assessment tool that can determine glycogen replenishment asymmetries in the RF.

Aerobic Capacity is Related to Repeated Sprint Ability with Sprint Distances Less Than 40 Meters.

Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ -0.69, P < 0.001) between VO2max and all 10-sprint times and average sprint time. More aerobically fit Division I soccer athletes were faster at all time points during the RSA test. Aerobic fitness is associated with faster sprint times during a more anaerobic RSA test when sprint distances are less than 40 meters.