The aging process is highly individualistic and complex, even when many confounding factors are removed, according to Ross D. Pollock, Ph.D., and his associates.
In a cross-sectional study of 125 highly active male and female cyclists aged 55-79 years, some associations were found between age and function, with maximal rate of oxygen consumption showing the closest association. The age of a given individual, however, could not be determined from his or her physiological profiling, even in functions for which some correlation was found, because of high variance.
Further study is needed to find reliable biomarkers of aging as well as the relationship between age and physiological function, the researchers concluded.
Read the full article at the Journal of Physiology (2015;593:657-80 [doi:10.1113/jphysiol.2014.282863]).