Fig. 3: Relationship between average rate of change in the population of a specific phenotype and rate of change of the same phenotype in individual BLSA participants.

a–c, The example reported in this figure uses the cost/capacity ratio, one of the phenotypes in the energetics domain, operationalized as the ratio between the energy cost of slow walking (ml kg^–1 min^–1) and energy capacity measured by peak oxygen consumption during a 400-m walk (ml kg^–1 min^–1) (detailed description in Supplementary Methods I). Number of participants, 755 (male 378, female 377). a, Spaghetti plot of longitudinal changes in cost-to-capacity ratio in men and women at the population level (thick blue and red lines, respectively) and for individual participants (thin lines), estimated from mixed-effect models (Methods and Supplementary Methods III). b,c, Estimated rates of change in cost/capacity ratio are depicted for individual participants (black dots; b, males; c, females) at their age of study entry. Bands of different color indicate how far the individual rates of change diverge from the population rate of change, expressed as s.d. Of note, because the rate of reference varies at different ages, a specific rate of change conveys information on accelerated or decelerated aging only when the specific age of the participant is considered.