Matching Items (2)
Description
More than 200 hikers are rescued annually in the greater Phoenix area. This study
examined the impact of hiking in hot (HOT), dry temperatures versus moderate (MOD)
temperatures on dietary intake behaviors as well as markers of heat stress. Twelve
recreational mountain hikers climbed “A” Mountain four consecutive times (4-miles) on
a HOT day (WBGT=31.6 °C) and again on a MOD day (WBGT= 19.0 °C). Simulated
food and fluid behavior allowed participants to bring what they normally would for a 4-
mile hike and to consume both ad libitum. The following heat stress indicators (mean
difference; p-value), were all significantly higher on the HOT hike compared to the MOD
hike: average core temperature (0.6 °C; p=0.002), average rating of perceived exertion
(2.6; p=0.005), sweat rate (0.54; p=0.01), and fluid consumption (753; p<0.001). On the
HOT hike, 42% of the participants brought enough fluids to meet their individual
calculated fluid needs, however less than 20% actually consumed enough to meet those
needs. On the MOD hike, 56% of participants brought enough fluids to meet their needs,
but only 33% actually consumed enough to meet them. Morning-after USG samples
≥1.020 indicating dehydration on an individual level showed 75% of hikers after the
HOT hike and 67% after the MOD hike were unable to compensate for fluids lost during
the previous day’s hike. Furthermore, participant food intake was low with only three
hikers consuming food on the hot hike, an average of 33.2g of food. No food was
consumed on the MOD hike. These results demonstrate that hikers did not consume
enough fluids to meet their needs while hiking, especially in the heat. They also show
heat stress negatively affected hiker’s physiological and performance measures. Future
recommendations should address food and fluid consumption while hiking in the heat.
examined the impact of hiking in hot (HOT), dry temperatures versus moderate (MOD)
temperatures on dietary intake behaviors as well as markers of heat stress. Twelve
recreational mountain hikers climbed “A” Mountain four consecutive times (4-miles) on
a HOT day (WBGT=31.6 °C) and again on a MOD day (WBGT= 19.0 °C). Simulated
food and fluid behavior allowed participants to bring what they normally would for a 4-
mile hike and to consume both ad libitum. The following heat stress indicators (mean
difference; p-value), were all significantly higher on the HOT hike compared to the MOD
hike: average core temperature (0.6 °C; p=0.002), average rating of perceived exertion
(2.6; p=0.005), sweat rate (0.54; p=0.01), and fluid consumption (753; p<0.001). On the
HOT hike, 42% of the participants brought enough fluids to meet their individual
calculated fluid needs, however less than 20% actually consumed enough to meet those
needs. On the MOD hike, 56% of participants brought enough fluids to meet their needs,
but only 33% actually consumed enough to meet them. Morning-after USG samples
≥1.020 indicating dehydration on an individual level showed 75% of hikers after the
HOT hike and 67% after the MOD hike were unable to compensate for fluids lost during
the previous day’s hike. Furthermore, participant food intake was low with only three
hikers consuming food on the hot hike, an average of 33.2g of food. No food was
consumed on the MOD hike. These results demonstrate that hikers did not consume
enough fluids to meet their needs while hiking, especially in the heat. They also show
heat stress negatively affected hiker’s physiological and performance measures. Future
recommendations should address food and fluid consumption while hiking in the heat.
ContributorsPelham, Emily Claire (Author) / Wardenaar, Floris (Thesis advisor) / Whisner, Corrie (Committee member) / Levinson, Simin (Committee member) / Arizona State University (Publisher)
Created2020
Description
Annually, more than 200 hikers are rescued in the greater Phoenix area. This study examined behavior influencing acute hydration status in hot (HOT) and moderate (MOD) climates, by examining fluid planning and decision making in combination with an educational video. A total of n=115 hikers completed self-paced hikes, n=56 hikers completed the hike in a HOT condition (wet bulb globe temperature [WBGT]=24.84°C) and n=59 hikers completed the hike in a MOD condition (WBGT=8.28°C). Real food and fluid behavior allowed participants to freely select the amount of food and fluid brought on the hike and intake was ad libitum. The following heat stress indicators were all significantly higher in the HOT condition compared to MOD condition (HOT median, MOD median; p-value): hike duration (1.48, 1.20; p<0.01), energy expenditure (561, 408, p<0.01), sweat rate (776, 465, p<0.01), and session rating of perceived exertion (RPE) scores (1177, 732, p<0.01). After watching a 3-minute hydration education video, and the opportunity to stock up on extra fluid, 54% of participants carried sufficient fluid in the HOT condition to meet their needs compared to 81% of participants in the MOD condition. However, only 23% of participants in the HOT condition consumed sufficient fluid to make up for fluid lost through sweating compared to 33% in the MOD condition. More than half of participants in the HOT condition (59%) and the MOD condition (76%) did not stock up on extra fluid after education. These results demonstrate that hikers did not consume sufficient fluids to meet their needs while hiking, especially in a hot climate. They also show heat stress negatively affected hikers’ performance measures. More research is required to assess the feasibility and efficacy of hydration related education videos at trailheads.
ContributorsNaldo, Rebecca (Author) / Wardenaar, Floris (Thesis advisor) / Vanos, Jennifer (Committee member) / Kavouras, Stavros (Committee member) / Arizona State University (Publisher)
Created2021