1. Executive function following acute exercise at different intensities
RACHAEL L. MCDONALD* & CHELSEA MOORE
Leeds Trinity University
*Corresponding author: Department of Sport, Health and Nutrition, Leeds Trinity University, United Kingdom.
INTRODUCTION
Chronic aerobic exercise beneficially influences brain function and cognition (Colcombe & Kramer, 2003).
This has important implications for any individuals or groups who are striving to improve executive functioning in sport, occupational (military or health) or academic settings.
A single bout of acute exercise positively affects basic information processing tasks such as reaction time (Tomporowski & Ellis, 1986).
Although similar cognitive facilitations have been observed on more complex cognitive processes (executive tasks) such as visual search, verbal fluency and visual short term memory following a single bout of exercise (Chang, Labban, Gapin & Etnier, 2012) the results have been inconsistent.
Therefore this study aims to investigate the relationship between exercise intensity and cognitive facilitation following 30-minute treadmill running.
METHODS
RESULTS
PARTICIPANTS
Twenty-one healthy adult men (mean ± SD, age 20.8 ± 1.6 years, body mass 79.9 ± 10.4 kg) completed a within-participant, repeated measures design.
PROTOCOL
Each participant completed a maximal incremental graded exercise test on a treadmill. Individual participant VO2max scores were used to determine running workloads at light (30%VO2max), moderate (50%VO2max) and hard intensities (70%VO2max). Executive function was assessed immediately before and after 30-minutes of treadmill running at each intensity using the Modified Flanker Test. Exercise (Eriksen & Eriksen, 1974).
Means ± standard deviations were calculated. Repeated measures analysis of covariance (ANCOVA) for time was employed to assess the main effect of exercise intensity on reaction times (RT, ms) and error rate (%).
Executive functioning following exercise
RT significantly improved following exercise (P < 0.01).
Pairwise comparisons indicated that RT following hard intensity exercise was significantly faster (m = ms, s =4.53) than either no exercise (m = , s =4.62) or light exercise (m = ms, s =4.59) (P<0.01, 95% Cl 6.786–41.186; P<0.01, 95% Cl 3.820–38.140, respectively).
Accuracy of response was not significantly affected by exercise (P>0.05).
Modified Flanker Test
On-screen instructions were provided for the test. Participants responded to the central letter (known as the target) whilst ignoring the outside letters (distracters) which 'flank' the target. Examples of congruent, neutral and incongruent condition are shown in Table 1. Reaction time (ms) and error rate (% accuracy) to the target letters were measured.
Table 1. Example of Modified Flanker Test trials.
Congruent
FFF, XXX
Neutral
LXL, LFL
Incongruent
XFX, FXF
* indicates significance compared to control (0% of V02max) † indicates significance compared to 30% of V02max.
REFERENCES
CONCLUSION
Colcombe & Kramer (2003). Psychol Sci. 14(2) :
Tomporowski, P.D. & Ellis, N.R. (1986). Psychological Bulletin. 99: 338–346.
Chang, Y.K., Labban, J.D., Gapin, J.I., & Etnier, J.L. (2012). Brain Research,1453:
Eriksen, B.A., & Eriksen, C.W. (1974). Percept. Psychophysiology, 16: 143–149.
A 30-minute bout of acute treadmill running at high intensity improves executive functioning.