title: Subjective ratings and performance in the heat and after sleep deprivation.
abstract: BACKGROUND
  It has been shown that endurance performance after one night of sleep deprivation is not compromised despite the feeling of fatigue and that, in contrast, performance in the heat deteriorates even though people may feel good. However, it is essentially unknown how the estimation of performance capabilities relate to actual performance. We hypothesized that endurance performance in the heat would be overestimated and performance after sleep deprivation would be underestimated. We also hypothesized that jumping performance will be underestimated in the heat.
  
  
  METHODS
  There were 11 fit (VO2peak 52.0 +/- 3.7 ml x kg(-1) x min(-1)) men, familiar with cycling, who performed a 20-min all-out cycling test (AO) and a vertical jump test (VJ) under four different conditions: a test trial at 24 degrees C, at 11 degrees C ambient temperature without (C) and with one night of sleep deprivation (CS), and at 31 degrees C (H). The subjects estimated the performance prior to exercise in CS, C, and H.
  
  
  RESULTS
  AO performance was less for H (6.95 +/- 0.36 km) than for C (7.68 +/- 0.29 km) and CS (7.62 +/- 0.33 km). The subjects underestimated AO performance for CS by 1.11 km and C by 0.42 kmin, but not for H. VJ was higher in the H condition, in contrast with subjects' assessment.
  
  
  CONCLUSIONS
  We conclude that subjective estimates of performance are not in line with actual performance for endurance exercise after sleep deprivation and for explosive exercise in the heat.
authors.affiliation: TNO Behavioral and Societal Sciences, Soesterberg, The Netherlands. hein.daanen@tno.nl
authors.forename: Hein A M
authors.initials: HA
authors.lastname: Daanen
authors.forename: Sam
authors.initials: S
authors.lastname: van Ling
authors.forename: T Koen
authors.initials: TK
authors.lastname: Tan
mesh_terms: D001831:Body Temperature; D005080:Exercise Test; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D006339:Heart Rate; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D012881:Skin Temperature; D012892:Sleep Deprivation / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D013647:Task Performance and Analysis; D055815:Young Adult