Clinical trial NCT05068804: Intermittent Cooling During Baseball Games on Hitting and Defense Performance
Official title: Intermittent Cooling During Baseball Games Alleviated Perceived Exertion But Had no Effect on Hitting and Defense Performance in Hot Environment
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Decline, Cognitive
Keywords: baseball
cognitive
cooling
Lead sponsor: National Taiwan Sport University
Sponsor class: OTHER
Collaborators: name: Ministry of Science and Technology, Taiwan
First posted: 2021-10-06
Enrollment: 10
Sex: MALE
Minimum age (years): 20
Maximum age (years): 23
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: This study adopted a practical approach in intermittent cooling on forehead and neck during an intra-squad baseball game. Exit velocity of batted balls was used as an indicator for hitting performance and a baseball-specific reactive agility test to evaluate the cognitive performance in defense.

Detailed description: This study used a randomized cross-over design. Each participant completed a cooling and a non-cooling trial in a random order, separated by a 20-day washout period. Each trial contained a 7-inning intra-squad game in hot environment. Hitting, reactive agility, and cognitive tests were administered before and after the game. Forehead skin and tympanic temperature, perceived exertion, and thermal sensation were measured during the game.

Experimental procedure After body weight and rectal temperature were measured in a temperature-controlled room, the participants consumed a standardized breakfast. The breakfast included white bread 1.2 g/kg, jam 0.1 g/kg, butter 0.l g/kg, and soybean milk 5 ml/kg (6.2 kcal/kg, containing carbohydrate 1.0 g/kg, protein 0.24 g/kg, and fat 0.14 g/kg). Go/NoGo and Stroop Color-Word tasks were administered after breakfast. After finishing the cognitive tests, the participants moved to the field for self-selected warm up, followed by hitting and reactive agility tests. After the intra-squad game, the participants repeated the hitting, reactive agility, and cognitive tests. The participants can drink water ad libitum during the experimental period.

Intra-squad game The 7-inning intra-squad games were played under the standard rules of baseball in hot environmental conditions (temperature 31.1-33.4℃, humidity 63-67%).

Cooling intervention The participants in the cooling trial put cold towels on their forehead and neck for 3 min in the shaded dugout during their offensive half innings when they were not scheduled to hit or on base. Each participant received the cooling intervention 3 to 4 times in each game. After each use, the towels were kept in a cooler that contained water mixed with ice and salt to keep the temperature at approximately 0℃. The participants in the control trial sat in the shaded dugout without any cooling intervention.

Measurement of temperature Rectal temperature was measured before breakfast and after the game with a digital thermometer fitted with disposable sheaths. Forehead skin and tympanic temperature were measured with infrared thermometers during their offensive half innings in the dugout.

Hitting test The participants used their own bat to hit balls thrown by a pitching machine positioned 12 m from the home plate. The ball speed was approximately 120 km/h. The participants were asked to make the best effort to hit the balls. Each test was consisted of 15 batted balls. Exit velocity was measured with a video system and swing power was measured with a sensor attached to the knob of the bat.

Reactive agility test The infielders played defense against ground balls at the short stop position while the outfielders played defense against fly balls in center field. The participants were asked to move toward the ball as soon as they determine the trajectory and make the best effort to catch it. Each test was consisted of 15 batted balls. The reaction time, the time from bat-ball contact to the participant's first definitive movement in the intended direction, was calculated post-hoc using frame-by-frame analysis of the video footage by an experienced coach

Cognitive tests The Go/NoGo and Stroop Color-Word tasks were administered on a laptop computer in a quiet room. Each task contained 100 trials.

Perceived exertion and thermal sensation The participants reported their perceived exertion and thermal sensation during their offensive half innings. Perceived exertion was estimated with a 10-point Borg scale. Thermal sensation was estimated with a 7-point scale from -3 being the coolest to 3 being the hottest.

Eligibility criteria: Inclusion Criteria:

* baseball players from National Taiwan University of Sport, Taiwan
* at least 6 years of experience in baseball training
* have competed nationally.

Exclusion Criteria:

* having cardiovascular or other known chronic diseases
* taking any medication in the preceding 2 months
* having musculoskeletal injuries in the preceding 2 months.

Primary outcomes:
measure: rectal temperature
timeFrame: baseline
measure: change in rectal temperature
timeFrame: 5 hours after the baseline
measure: forehead skin temperature
timeFrame: baseline
measure: change in forehead skin temperature
timeFrame: 2 hours after the baseline
measure: tympanic temperature
timeFrame: baseline
measure: change in tympanic temperature
timeFrame: 2 hours after the baseline
measure: exit velocity of batted balls
timeFrame: baseline
measure: change in exit velocity of batted balls
timeFrame: 3 hours after baseline
measure: reactive agility in defense
timeFrame: baseline
measure: change in reactive agility in defense
timeFrame: 3 hours after baseline
measure: swing power
timeFrame: baseline
measure: change in swing power
timeFrame: 3 hours after baseline
Secondary outcomes:
measure: ratings of perceived exertion
timeFrame: baseline
measure: change in ratings of perceived exertion
timeFrame: 2 hours after baseline
measure: thermal sensation
timeFrame: baseline
measure: change in thermal sensation
timeFrame: 2 hours after baseline
measure: Go/NoGo tasks
timeFrame: baseline
measure: change in Go/NoGo tasks
timeFrame: 5 hours after baseline
measure: Stroop Color-Word test
timeFrame: baseline
measure: change in Stroop Color-Word test
timeFrame: 5 hours after baseline
Other outcomes:
Locations:
city: Taichung
country: Taiwan
facility: National Taiwan University of Sport
Study officials:
affiliation: National Taiwan University of Sport
name: Chen-Kang Chang
role: PRINCIPAL_INVESTIGATOR
References: