The global climate is changing, 2016 was the third consecutive hottest year on record (MET Office, 2016) and as the mean global temperature rises so does the frequency, severity and duration of heatwaves (Hajat et al., 2014). This presents a significant health risk to the population, with the elderly being the most vulnerable to heat-related illnesses and death due to a reduced capacity to dissipate excess heat (Kenney et al., 2014). Consequently, up to 90% of excess deaths during heatwaves occur in people over 65 years (Conti et al., 2005). The aim of this investigation was to assess the physiological and perceptual responses of elderly people during exercise in UK summer climatic conditions. Twenty- eight participants (18 males and 10 females: age; 71 ± 4 years, body mass; 76.9 ± 15.1 kg, body fat percentage; 22.7 ± 3.9%) were randomly assigned into three experimental groups; 15°C, 25°C or 35°C, 50% relative humidity. Participants completed a preliminary trial and three experimental trials within their assigned environment. The data from the preliminary incremental recumbent cycling test was used to calculate individual exercise intensities equating to 2, 4 and 6 metabolic equivalents (METs) for the subsequent trials. In the experimental trials participants completed 30 minutes of seated rest and 30 minutes of cycling exercise. Throughout the experiment heart rate, core temperature (Tc) and skin temperature (Tskin) were recorded every 5 minutes; and rating of perceived exertion, thermal sensation (TS) and thermal comfort (TC) every 10 minutes. End Tskin increased significantly (P < 0.05) with environmental temperature when exercise intensity did not change. Furthermore, ΔTc increased significantly (P < 0.05) from rest to end exercise when exercise intensity remained the same and environmental temperature was increased from 15-35°C and from 25-35°C, highlighting a significant increase in thermal strain. However, there was no significant increase (P>0.05) in end TC and TS when completing exercise at 6 METs in 25°C compared to 35°C. Findings suggest that when completing exercise that equates to activities of daily living, elderly people could have a decreased perceptual awareness of the environment due to significant increases in Tskin and ΔTc, but no changes in end TC (see figure 1) and minimal changes in end TS between exercising at 6 METs in 25°C compared to 35°C. The potential consequence of a decreased perceptual awareness of the environment is that the elderly will be less likely to implement lifesaving behavioural thermoregulation interventions such as; seeking shade, decreasing metabolic rate and removing excess layers, as thermal comfort is the drive for thermoregulatory behaviour (Flouris, 2011).
|Publication status||Published - 2017|