Research Study

Questions and Hypotheses

What are the cooling rates for body cooling with vest (on the front) compared to passive cooling in runners completing a road race in hot environmental conditions?

Hypotheses

We hypothesize that the cooling rates for body cooling using ColdVest will be greater than that of passive cooling in the shade (<0.08°C /minute).some text inside of a div block.

What are the effects of post-race body cooling on internal body temperature in runners competing in a road race in hot environmental conditions?

Hypotheses

We hypothesize that runners who receive body cooling using ColdVest will have a lower internal body temperature compared to those who receive passive cooling.

Methods Overview

This study was a quasi-randomized control trial in which participants were assigned to the vestcooling group (n=15) or the control group which was passive cooling (n=10).

Participant Assignment Protocol

Following the race, participants were assigned to either body cooling with a vest (n=15) or passive cooling (n=10). Assignments were determined by internal body temperature to:

Ensure the safety of participants first.

Ensure equal distribution of body cooling participants (goal n=15) and passive cooling participants (goal n=10) in the following temperature zones.

Temperature Zone Assignments

Body cooling with vest: The vests were filled by research staff with chilled water (< 17°C). Participants were prompted to lie supine in the shade on a cot while donning the vest on their front. Participants were instructed to refrain from consuming any food or fluid for a maximum of 30 minutes while having their rectal temperature recorded approximately every 5 minutes by research staff. When cooling was considered complete, the vests were removed and the participant was monitored for five more minutes.

Cooling Timeline: Cooling was considered complete when rectal temperature reached 38.5°COR 30 minutes of cooling has passed.

Protocol Design

Baseline

Anthropometrics

Pre-race Data Collection

Internal body temperature, urine sample, body mass, saliva sample, stool sample (within 24h of race start)
Environmental monitoring

During Race Data Collection

Environmental monitoring

Post-race Data Collection

Internal body temperature, urine sample, body mass, saliva sample, stool sample (post 24h and 48h)
Environmental monitoring

Figure 1. Protocol design

Dependent Variables

*Urine Specific Gravity (USG): compares the density of urine with the density of water. The higher the number of particles in the urine, the higher the urine specific gravity. We consider values 1.020 and lower adequately hydrated for our research studies. The lowest it can be is 1.000.

**Urine Color: uses a specific chart to quantify the color of a urine sample. It ranges from one to eight. The clearest urine would be a one, and the darkest would be an eight. We most commonly see values from one to six.

Results

Participant Characteristics

Table 1. Participant Characteristics (mean ± standard deviation)

Note: Indicates significant difference from V3 (Passive) at respective time point. Post-Race Trec V1 was significantly higher than V3 (p = 0.003).

Hydration Assessment

Table 2. Hydration Assessment (USG and Urine Color) Pre-Race to Race Finish

Note: There were no statistical differences (p>0.05) between groups.

Figure 2. Indicates significant difference from passive cooling. Post race there was a statistical difference betweenthe single vest group (40.18 ± 0.43°C), and the control group (38.97± 0.95°C, p=0.003).

Figure 3. Cooling Time in Hyperthermic Runners by Group. There is no statistical significance between cooling time occurred (P>0.05).

Figure 4. Rectal temperature in hyperthermic runners at the start and end of intervention between each group. *Indicates significant difference from passive cooling. The vest (1.83 ±0.80°C) had a statistically higher drop in degrees than the control group (0.60 ± 0.44°C).

Interpretation: Vest group had higher start temperatures compared to the passive group. Both groups were cooled to the same temperature.

Figure 5. Mean cooling rate of hyperthermic runners during post-race intervention. There was a statistical difference between the single vest group (0.18 ± 0.07°C) and the control group (0.06 ±0.030°C) in which the single vest had a significantly higher cooling rate (p<0.001).

Interpretation: The vest group cooled people at a significantly faster rate than the passive coolinggroup.

Cooling Rate, Finish Line Body Temperature & Body Surface Area

Figure 6. Rectal temperature pre intervention and cooling rate correlation in HyperthermicRunners. There is no statistical significance between cooling rates based on starting rectaltemperature.

Interpretation: There was no association between cooling rate and starting rectal temperature. (note thatpassive is not included on this graph)

Figure 7. Body Surface Area and Cooling Rate Correlation With Vest Cooling in Hyperthermic Runners. There is no statistical significance in cooling rates.

Interpretation: There was no association between cooling rate and body surface area. (note that passiveis not included on this graph)

Result Overview

Objective

To examine if the ColdVest significantly reduces internal body temperature post-race.

Questions and Hypotheses

What are the cooling rates for body cooling with vest (on the front) compared to passive cooling in runners completing a road race in hot environmental conditions?

Hypotheses

We hypothesize that the cooling rates for body cooling using ColdVest will be greater than that of passive cooling in the shade (<0.08°C /minute).some text inside of a div block.

Result:

ColdVest had a faster cooling rate compared to passive cooling.

What are the effects of post-race body cooling on internal body temperature in runners competing in a road race in hot environmental conditions?

Hypotheses

We hypothesize that runners who receive body cooling using ColdVest will have a lower internal body temperature compared to those who receive passive cooling.

Result:

The runners who received body cooling via ColdVest achieved a lower internal body temperature faster compared to those who received passive cooling.