Is obesity associated with impaired reaction time in youth?

BACKGROUND AND PURPOSE: Recent research demonstrates a significant relationship between weight status and impaired reaction time in young, adult, and elderly individuals. However, most such studies were performed on small samples, used only body mass index as the body obesity index, used simple reaction time, and oftentimes did not consider some potential confounders such as age, socioeconomic status, or physical activity in their studies. The present study explored the relationship between various reaction time tasks and various obesity indices in a sample of youth. METHODS: Two hundred and thirty-four young males (19-24 years) underwent standard anthropometry, various information processing tasks (e.g., clinical reaction time, simple audio and visual reaction time, and choice reaction time), as well as an inhibitory control task (congruent and incongruent Simon reaction time). RESULTS: Results revealed no significant relationship between any of the information processing tests and body mass index, nor for fat percentage, waist circumference, and waist-to-height ratio after adjustment for potential confounders. A weak positive association was observed only between congruent Simon reaction time (but not incongruent Simon reaction time) and waist circumference in participants (t value = 0.199; Std error = 0.0014; p = 0.047; Cohen's f2 = 0.09). CONCLUSION: Inhibitory control, but not information processing speed, was associated only with waist circumference in apparently healthy young men. LEVEL OF EVIDENCE: Level I, experimental study.

Association between physical fitness and cognitive performance in 19-24 year old males.

The present study aimed to explore the association between physical fitness (PF) and cognitive performance in a sample of 19-24 year old males. Two hundred and eleven young males (20.2±1.5 years) participated in the study. Cognitive functioning tasks including information processing speed and inhibitory control were measured in addition to PF and motor fitness components such as aerobic fitness, static strength, explosive strength, agility and speed. Regression analysis showed that after adjustment for potential confounders (e.g. age, socioeconomic status, adiposity and physical activity), aerobic fitness (represented by shorter time in the one-mile run) was positively associated with composite inhibitory control scores (standardized ß=0.17; p=0.04) and negatively associated with ∆ Simon (standardized ß= -0.21; p=0.04). Explosive strength was negatively associated with composite information processing scores (standardized ß= -0.24; P=0.01), and composite inhibitory control scores (standardized ß= -0.22; p=0.02). Speed of movement, agility and static strength were not associated with any of the cognitive tests. In conclusion, aerobic fitness and explosive strength but not speed, agility or static strength might be indicators of underlying cognitive functioning tasks in 19-24 year old males.