Neck Cooling Improves Table Tennis Performance amongst Young National Level Players

Design and Validation of Novel Evaporative Local Cooling Coatings to Prevent Adverse Health Effects of Heat Exposure

Background

This study aimed to design and evaluate the cooling power of local cooling coats for the head, neck, ankles, and wrists.

Methods

Local cooling coatings were designed using Iranians workers' existing 50^th anthropometric percentile data. After immersing the cooling coats in water for 5 minutes, they were placed in a chamber at 30°C, 35°C, and 40°C and 30% and 60% humidity and 0.2-0.4 m/s air velocity for 120 minutes. The amount of water evaporation was measured by weighing each coat before and after entering the chamber, and then the cooling power of each coat was calculated based on the amount of water evaporation.

Results

The average cooling power of cooling coats with covering areas (two wrists 933.75 cm², two ankles 1467.37 cm² and head and neck 1270 cm²) that the total area of the cover is 3671.12 cm², i.e., about 20% of the body at 30% relative humidity in 30°C, 35°C and 40°C was 67, 77 and 89 watts, respectively. At the mentioned temperature and in 60% relative humidity, the cooling power was 34, 40, and 55 watts. As the relative humidity increased, the cooling power of the coats decreased.

Conclusions

Local evaporative cooling coat on the head, neck, wrists, and ankles can reasonably repel excess heat entering the body. The best performance of these coats is in hot and dry environments. Probably, if used in conjunction with cooling vests in environments with high temperatures and heavy activity, it can act as a supplement to cooling vests and have a significant effect on improving functions.

Intermittent Cooling Reduces Perceived Exertion but Has No Effect on Baseball Hitting or Defense Performance in a Hot Environment

Hot environments can impair the complex cognitive functions that are crucial to baseball hitting and defense. This study investigated the effects of intermittent forehead and neck cooling on the hitting and reactive agility of baseball players in hot environments. Ten male collegiate baseball players played 7-inning intrasquad games in a hot environment (31.1°C - 33.4°C), completing one cooling and one control trial in a randomized crossover design. In the cooling trial, the participants placed ice-cold towels on their forehead and neck for 3 min during offensive half innings. Hitting and reactive agility tests, a go/no-go task, and the Stroop Color and Word Test were administered before and after each game. The games in the hot environment significantly increased rectal temperatures to the same level in the control (38.15°C ± 0.31°C, p < 0.001) and cooling (38.08°C ± 0.24°C, p < 0.001) trials. Intermittent cooling significantly reduced forehead and tympanic temperatures, perceived exertion, and thermal sensation during the game. Swing power significantly increased after the game, but the exit velocity of batted balls did not significantly differ in both trials. Reactive agility was significantly impaired after the game in the control trial (before: 0.367 ± 0.109 s, after: 0.491 ± 0.212 s, p = 0.008) but displayed a trend of decrease in the cooling trial (before: 0.390 ± 0.183 s, after: 0.518 ± 0.282 s, p = 0.066). The game and cooling intervention had no significant effects on the reaction time or error rate in the go/no-go task and Stroop Color and Word Test. The results showed that intermittent cooling during a baseball game in a hot environment reduces perceived exertion and thermal sensation but has no significant effect on hitting, defense performance, or cognitive function.

Head, Face and Neck Cooling as Per-cooling (Cooling During Exercise) Modalities to Improve Exercise Performance in the Heat: A Narrative Review and Practical Applications

It is well known that uncompensable heat stress greatly impairs endurance and team sport-related performance because an increase in the core temperature directly induces a greater magnitude of the central fatigue in the heat than in thermal neutral environments. Numerous studies have been conducted in an attempt to discover reliable cooling strategies for improving endurance performance and repeated sprint ability while exercising in the heat. Whole-body pre-cooling has been shown to improve endurance performance in both dry and humid heat. Despite this, the reduction in thermal perceptions associated with pre-cooling gradually narrows during intense exercise. Hence, effective per-cooling strategies to improve athletic performance in the heat are required. Unfortunately, due to practical issues, adopting pre-cooling approaches as a per-cooling (cooling during exercise) modality to improve athletic performance is impractical. Thus, we sought to examine the impact of head, neck and face cooling on athletic performance in heat. According to current evidence, cooling the head, neck and face reduced local skin temperature in the areas where cooling was applied, resulting in improved local perceptual sensations. In the heat, neck cooling during exercise improves athletic performance in both endurance and team sports athletes. Furthermore, from a practical standpoint, neck cooling is preferred over head, face and combined head/face and neck cooling for both endurance and team sport athletes in the heat. Nonetheless, for all athletes who have access to water, face cooling is a recommended cooling strategy. There is a lack of research on the systematic selection of per-cooling modalities to improve athletic performance based on environmental conditions and the nature of sports. In addition, powerful but portable head, neck and face cooling systems are urgently needed to assist athletes in improving their performance in hot conditions.

Lower-Limb Passive Heat Maintenance Combined With Pre-cooling Improves Repeated Sprint Ability

Pre-conditioning strategies to potentiate performance are a common feature of pre-competition routines. The elevation of muscle temperature is seen as a vital component of preparing for physical performance, while pre-cooling strategies have been adopted to offset fatigue during repeated efforts. We investigated the individual and combined effects of a passive heat maintenance strategy and the ingestion of an ice-water slurry on repeated sprint performance. In a random cross-over design, 12 professional male athletes performed 5 × 40 m maximal running sprints under one of four conditions following a standardized warm-up: 15-min passive rest (Control); wearing a lower-body survival garment (HEAT); consuming a 500 mL ice slushy (COLD); or wearing the survival garment and consuming the slushy (H+C). Measures of sprint speed, fatigue, heart rate, and rectal temperature were collected. Compared to COLD: HEAT improved Sprint 1 (ES: 0.84; p = 0.05), but negatively impacted Sprint 4 (ES: -0.87; p = 0.08), and Sprint 5 (ES: -1.57; p = 0.002). H+C was faster than Control for every sprint (ES: 0.28 to 0.66), clearly faster than COLD on Sprints 1–3 (ES: 0.73 to 0.54), and clearly faster than HEAT on Sprints 4 and 5 (ES: 1.31 and 1.87). Fatigue was greatest after the HEAT intervention with a large correlation between fatigue and rectal temperature (r = 0.66; p = 0.0204). While there are undoubtedly peripheral effects of cooling and heating on various aspects of muscle function and fatigue, understanding the integration of psychophysiological homeostatic feedback loops relating to a combined warming and cooling intervention may benefit sports in which repeat sprints are performed.

The Effect of Teaching Games of Understanding as a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian and Indian Junior Hockey Players

The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU) model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT), among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR) at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes’ recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated no significant difference between these two instruction types among Malaysians, although TGfU proved to have higher HR intensity. Therefore, these findings reiterated that TGfU is a useful approach for game play to enhance intensity and cardiac output. In conclusion, for TGfU to be more relevant to the coaching environment, future research should link game play and physiological parameters. TGfU should able to overcome the barriers of tradition and cultural background that may hinder its momentum