During play, ice hockey goaltenders routinely dehydrate through sweating and lose ≥2% body mass, which may impair thermoregulation and performance. Purpose: This randomized, crossover study examined the effects of mild dehydration on goaltender on-ice thermoregulation, heart rate, fatigue, and performance. Methods: Eleven goaltenders played a 70-minute scrimmage followed by a shootout and drills to analyze reaction time and movements. On ice, they either consumed no fluid (NF) and lost 2.4% (0.3%) body mass or maintained body mass with water (WAT) or a carbohydrate–electrolyte solution (CES). Save percentage, rating of perceived exertion, heart rate, and core temperature were recorded throughout, and a postskate questionnaire assessed perceived fatigue. Results: Relative to NF, intake of both fluids decreased heart rate (interaction: P = .03), core temperature (peak NF = 39.0°C [0.1°C], WAT = 38.6°C [0.1°C], and CES = 38.5°C [0.1°C]; P = .005), and rating of perceived exertion in the scrimmage (post hoc: P < .04), as well as increasing save percentage in the final 10 minutes of scrimmage (NF = 75.8% [1.9%], WAT = 81.7% [2.3%], and CES = 81.3% [2.3%], post hoc: P < .04). In drills, movement speed (post hoc: P < .05) and reaction time (post hoc: P < .04) were slower in the NF versus both fluid conditions. Intake of either fluid similarly reduced postskate questionnaire scores (condition: P < .0001). Only CES significantly reduced rating of perceived exertion in drills (post hoc: P < .05) and increased peak movement power versus NF (post hoc: P = .02). Shootout save percentage was similar between conditions (P = .37). Conclusions: Mild dehydration increased physiological strain and fatigue and decreased ice hockey goaltender performance versus maintaining hydration. Also, maintaining hydration with a CES versus WAT may further reduce perceived fatigue and positively affect movements.

PurposeThe purposes of this study were to quantify the external load for female and male varsity ice hockey players during regular season games using a local positioning system (LPS), compare LPS-derived external load between sexes and positions, and compare skating distances in absolute and relative speed zones.MethodsData were collected for 21 female (7 defense, 14 forwards; 20.0 ± 1.4 yrs., 69.1 ± 6.7 kg, 167.1 ± 5.4 cm) and 25 male (8 defense, 17 forwards; 21.9 ± 1.1 yrs., 85.9 ± 5.4 kg, 181.1 ± 5.2 cm) varsity ice hockey players. Measures included skating distance (total, and in absolute and relative speed zones), peak skating speed, peak acceleration and deceleration, accumulative acceleration load, and number of accelerations, decelerations, turns, skating transitions, direction changes, and impacts.ResultsFemale and male players had a high external load during games, with average peak skating speeds &gt;28 km/h and average skating distances &gt;4.4 km. Most LPS-derived measures showed greater external load in males than females (p &lt; 0.05). Forwards skated further at higher speeds compared to defense in both sexes (p &lt; 0.001). Skating distances were significantly different when comparing absolute and relative speed zones (p &lt; 0.001), with absolute speed zones potentially overestimating skating at very slow, very fast, and sprint speeds and underestimating skating at slow and moderate speeds.ConclusionThis was the first study to measure external load in female ice hockey players with a LPS. Both female and male varsity players had high external loads during games, with forwards having greater external load at higher intensities and defense having greater external load at lower intensities. Sex and positional differences outline the importance of individualized athlete monitoring.

Nyman, DLE and Spriet, LL. External training demands in women's varsity rugby union players quantified by wearable microtechnology with individualized speed thresholds. J Strength Cond Res 36(11): 3151–3158, 2022—This study used wearable Global Positioning System (GPS) microtechnology with individualized speed thresholds to examine external training demands in 29 female varsity rugby union athletes during competitive season practices. Players were categorized as forwards or backs and observed during fitness, game-based, or skill training days (FT/GT/ST). Global Positioning System–derived variables included distances, high-intensity running (HIR), work-to-rest ratio, power plays, and PlayerLoad. Five speed zones categorized athlete movements and were customized according to each individual's overall maximum velocity (V̇max). Compared with backs, forwards had lower overall V̇max (6.62 ± 0.66 m·s−1; 7.38 ± 0.61 m·s−1, p = 0.003) and HIR thresholds (3.97 ± 0.40 m·s−1; 4.43 ± 0.37 m·s−1, p = 0.003). There were no interaction effects between position and training day for any GPS-derived variables. However, there were several effects of position (p ≤ 0.05), with forwards being lower than backs in mean V̇max, zone 1 distance, and power plays, and greater than backs in zone 3, zone 4, and HIR distances. Effects of the training day (p ≤ 0.05) were also observed in zone 1 distance, with FT being lower than GT and ST, and in power plays, with FT being greater than ST. In female varsity rugby union athletes, there were significant positional differences in individualized speed thresholds and external training demands. However, there were few marked differences between fitness, game-based, and skill training days.

This study determined the reliability and validity of a Kinexon local positioning system (LPS) for measuring external load in ice hockey players during an on-ice session. Fourteen ice hockey players (25.1 y, 78.6 kg, 176.9 cm) wore two LPS sensors to examine the inter-sensor reliability of the LPS during an on-ice session, and LPS speed and acceleration were measured during 40 m linear on-ice sprints and compared to a previously validated robotic sprint device to examine LPS accuracy. The coefficient of variation (CV), standard error of measurement (SEM), and intraclass correlation coefficient (ICC) were calculated for each LPS measure. Pearson's correlations, simple linear regressions, and Bland-Altman plots were used to test the agreement and relationship between the two systems. Statistical significance was determined at p < 0.05. The majority of LPS measures were reliable (CV < 10% and ICC > 0.9) when comparing the two sensors worn by each player. Peak speed, speed at 5 m, and 0-5 m acceleration were all comparable to those reported by the robotic sprint device, with nearly perfect (peak speed and 0-5 m acceleration) and very large (speed at 5 m) magnitudes of correlation and mean biases <0.5 km/hr for speed measures and <0.01 m/s 2 for acceleration. The present results demonstrate that the Kinexon LPS is reliable and accurate for investigating on-ice external load in ice hockey players when sensors are consistently secured on the back of the players' shoulder pads.