Deception of Ambient Temperature Does Not Elicit Performance Benefits During a 5 km Run in Hot, Humid Conditions

Abstract

Hanson, NJ, Carriveau, DM, Morgan, HE, Smith, AR, Michael, TJ, and Miller, MG. Deception of ambient temperature does not elicit performance benefits during a 5 km run in hot, humid conditions. J Strength Cond Res 32(8): 2250-2257, 2018-The purpose of this study was to investigate the effect of deception of ambient temperature on 5 km performance in recreational runners. Eleven participants (6 men, 5 women) each performed three 5 km runs in a random order consisting of a control trial (CON) in temperate conditions (21° C, 43% RH), a hot humid trial (HOT; 31° C, 65% RH) and a deception trial (DEC; 31° C, 65% RH), where participants were told it was 5° C lower than it actually was. Overall completion time was recorded at the end of trials; thermal sensation (TS), rating of perceived exertion (RPE), and core temperature (TC) were recorded each kilometer. Participants completed the 5 km run faster in the CON condition (23:18 ± 2:05; mean ± SD) compared with DEC (p = 0.005) and HOT (p = 0.014). There was no difference in completion time (p = 0.554) between DEC (25:11 ± 2:41) and HOT (24:25 ± 2:47). Similarly, TS was lower in the CON condition (5.7 ± 0.2) compared with DEC and HOT (p < 0.001 and p = 0.016, respectively) and no differences were seen between the DEC (6.4 ± 0.2) and HOT (6.5 ± 0.2) conditions. No differences in RPE (p = 0.115) or rise in TC (p = 0.289) were seen between the 3 conditions. Deception of the environmental conditions did not positively affect 5 km running performance, and no differences were seen in physiological or psychological variables.

The impact of environmental temperature deception on perceived exertion during fixed-intensity exercise in the heat in trained-cyclists

“…Our study supports this conclusion, as T ̅ sk (Fig. 2B) was not different in the heat, and RPE was matched between conditions [14,15,20]. When T ̅ sk , T re and HR were included as standardised covariates [29] Following data collection, participants were informed of the true study aim and given a synopsis of the study results.…”

“…A greater amount of work was completed when RPE was lower, ameliorating the heat-induced reduction in performance observed when accurate temperature feedback was provided. In contrast, the isolated deception of ambient temperature was found to have no statistical impact on RPE during a 5 km self-paced run in 31 °C [20]. Nonetheless, there was a trend for lower RPE responses (~0.6 units) at the start of the run (1 km) compared the accurate feedback condition.…”

“…The application of Bayesian methods in sports science and a detailed explanation of the statistical framework can be found elsewhere [29]. No empirical evidence was able to be drawn upon from Castle et al [13] and Hanson et al [20] for the current study due to differences in methodological design. Therefore, an uninformative prior distribution was used for each parameter to allow inferences to be driven by the observed data [29].…”

“…The responses confirmed that participants did not know the true study aim, and they did not suspect the use of deception. Interestingly, despite a belief they were cycling in different ambient temperatures, this was not reflected in thermal sensation and comfort ratings [13,20].…”

“…where changes in RPE may be masked by alterations in mechanical work [13,20]. Where deception has been shown to improve performance and lower RPE [13], the type of deception has not been used in isolation, making it difficult to conclude the effective source (i.e., body or environment).…”