Purpose: The purposes of this study were to (a) investigate the effect of physical effort (cycling for 60 min at 60 ± 5% of individually computed reserve heart-rate capacity), combined with 2 different levels of cognitive demand (2-back, oddball), on intraocular pressure (IOP) and subjective judgments of perceived exertion (ratings of perceived exertion [RPE]), affect (Affective Valence subscale of the Self-Assessment Manikin [SAM]), and mental workload (National Aeronautics and Space Administration Task Load Index [NASA-TLX]); and (b) ascertain whether baseline IOP, measured before exercise, is associated with individual differences in subjective assessments of effort and affective response during exercise.
Method: Seventeen participants (Mage = 23.28 ± 2.37 years) performed 2 physical/cognitive dual tasks, matched in physical demand but with different mental requirements (2-back, oddball). We assessed IOP before exercise, after 2 min of active recovery, and after 15 min of passive recovery, and we also collected RPE and SAM measures during the sessions (28 measurement points). We used NASA-TLX and cognitive performance as checks of the mental manipulation.
Results: (a) Intraocular pressure increased after concomitant physical/mental effort, with the effect reaching statistical significance after the 2-back task (p = .002, d = 0.35) but not after the oddball condition (p = .092, d = 0.29). (b) Baseline IOP was associated with subjective sensitivity to effort and showed statistical significance for the oddball condition (p = .03, ƞp2 = .622) but not for the 2-back task (F < 1).
Conclusions: Results suggest a relationship between IOP and physical/cognitive effort, which could have implications for the management of glaucoma. Additionally, a rapid measure of IOP could be used as a marker of individual effort sensitivity in applied settings.
Keywords: Exercise evaluation; exercise testing; health; perceived exertion.