title: Heating Up to Keep Cool: Benefits and Persistence of a Practical Heat Acclimation Protocol in Elite Female Olympic Team-Sport Athletes

authors: Fenemor, Stephen Paul

subjects: Olympic sport

abstract: PURPOSE: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program. METHODS: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay). RESULTS: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41). CONCLUSIONS: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.

text: Heating Up to Keep Cool: Benefits and Persistence of a Practical Heat Acclimation Protocol in Elite Female Olympic Team-Sport Athletes PURPOSE: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program. METHODS: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay). RESULTS: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41). CONCLUSIONS: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.

year: 2023-03-01

title: Nonlinear and linear timescales near kinetic scales in solar wind turbulence

authors: Matthaeus, William H.

subjects: Science & Technology

abstract: The application of linear kinetic treatments to plasma waves, damping, and instability requires favorable inequalities between the associated linear timescales and timescales for nonlinear (e.g., turbulence) evolution. In the solar wind these two types of timescales may be directly compared using standard Kolmogorov-style analysis and observational data. The estimated local (in scale) nonlinear magnetohydrodynamic cascade times, evaluated as relevant kinetic scales are approached, remain slower than the cyclotron period, but comparable to or faster than the typical timescales of instabilities, anisotropic waves, and wave damping. The variation with length scale of the turbulence timescales is supported by observations and simulations. On this basis the use of linear theory—which assumes constant parameters to calculate the associated kinetic rates—may be questioned. It is suggested that the product of proton gyrofrequency and nonlinear time at the ion gyroscales provides a simple measure of turbulence influence on proton kinetic behavior.

text: Nonlinear and linear timescales near kinetic scales in solar wind turbulence The application of linear kinetic treatments to plasma waves, damping, and instability requires favorable inequalities between the associated linear timescales and timescales for nonlinear (e.g., turbulence) evolution. In the solar wind these two types of timescales may be directly compared using standard Kolmogorov-style analysis and observational data. The estimated local (in scale) nonlinear magnetohydrodynamic cascade times, evaluated as relevant kinetic scales are approached, remain slower than the cyclotron period, but comparable to or faster than the typical timescales of instabilities, anisotropic waves, and wave damping. The variation with length scale of the turbulence timescales is supported by observations and simulations. On this basis the use of linear theory—which assumes constant parameters to calculate the associated kinetic rates—may be questioned. It is suggested that the product of proton gyrofrequency and nonlinear time at the ion gyroscales provides a simple measure of turbulence influence on proton kinetic behavior.

year: 2014-08-01

title: Eta Mokena, daughter of Mokena Hou, and her husband, Hare Renata

authors: Hart, Philip

abstract: The family backgrounds of both Eta Mokena and Hare Renata can be traced, but little is known about her life compared with that of her husband. From an early age he lived in various places in Hauraki, cultivating, running pigs, catching birds, fish, and eels, and selling some of these to Pakeha. Both owned interests in several blocks of land, and Eta, being childless, gifted some interests to her nephew and nieces. Hare Renata had to fight off other claimants for several blocks of land, not always successfully, and not always by giving truthful evidence. Despite selling some of their interests in land, they were never financially secure.
Renata held interests in three goldfields whereas Eta held only one, in a claim named after her family. They settled in several places, and only rarely lived at Te Aroha until their last years.

text: Eta Mokena, daughter of Mokena Hou, and her husband, Hare Renata The family backgrounds of both Eta Mokena and Hare Renata can be traced, but little is known about her life compared with that of her husband. From an early age he lived in various places in Hauraki, cultivating, running pigs, catching birds, fish, and eels, and selling some of these to Pakeha. Both owned interests in several blocks of land, and Eta, being childless, gifted some interests to her nephew and nieces. Hare Renata had to fight off other claimants for several blocks of land, not always successfully, and not always by giving truthful evidence. Despite selling some of their interests in land, they were never financially secure.
Renata held interests in three goldfields whereas Eta held only one, in a claim named after her family. They settled in several places, and only rarely lived at Te Aroha until their last years.

year: 2016