Medical Research: What is the background for this study?
Response: A sufficient level of physical capability is a precondition for maintaining independence and quality of life. Physical capability can be assessed objectively by tests of physical performance, for instance handgrip strength, chair-rising and postural balance. Physical performance is associated with mortality and disability in late life, so gaining insights into the variance in physical performance is important to promote sustained physical capability and prevent disability. Research has previously found physical activity, health status and socioeconomic position to be associated with physical performance. In addition, early life factors, such as childhood SEP, have been found to be associated with measures of physical performance later in life. The objective of our study was to examine the association between intelligence in early adulthood and midlife physical performance in Danish men.
If an association between intelligence in early life and midlife physical performance exists it may indicate that cognitive abilities and physical performance share some of the same neurodevelopmental processes, but may also indicate that intelligence has an independent effect on later physical performance through various pathways.
Medical Research: What are the main findings?
Response: In our study of more than 2800 Danish men, we found positive associations between intelligence in early adulthood and five objective measures of physical performance in midlife independent of other early life factors. A one standard deviation increase in intelligence score resulted in 1.1 more chair-rises in 30 seconds, a 1 cm higher jump, a 3.7% smaller balance area, a 0.7 kg increase in handgrip-strength, and a 0.5 kg increase in lower back force.