TABLE 1.

Characteristics and results of studies investigating the correlation between early life (≤30) physical exercise and cognitive aging (≥60).

Study/country	Participants	Physical activity	Cognitive tests	Statistical adjustment	Results after full adjustment
Dik et al., 2003/Netherlands	1,241 – M (48.7%) and F (51.3%), aged 62–85 (mean 74.9), CI excluded, No info on ethnicity	15–25 years Asked retrospectively no. of hours per week	GCF (MMSE), SP (Alphabet coding task-15)	Confounders: age, sex, verbal intelligence, SES, lifestyle (early life physical work, current physical activity, smoking, alcohol), health indicators (diabetes, cardiac disease, depression)	GCF – no significance, SP – M only positive association for low (beta = 0.97) and mod (0.67) high – insignificant negative association (−1.04)
Fritsch et al., 2007/United States	349 – M (42.4%) and F (57.6%), aged 74 – 76 (mean 74.8), CI excluded, 99.7% white	16–18 years Information collected from yearbooks – grouped according to number of physical activities	GCF (TICS-m), SP (Timed months of the year backward test), episodic memory (Logical memory A subtest of the wechsler memory scale), verbal fluency (animal naming)	Path analysis for: sex, teen IQ, parent’s SES, HS physical, mental, social activities, ML mental, physical and social occupational demands, education	No association
Middleton et al., 2010/United States	9344 – only F, ≥65 years (mean 71.6), “primarily white” – no figures provided	“teenage” Asked retrospectively about low, mod, high intensity exercise – modified Paffenbarger questionnaire	GCF (mMMSE)	Confounders: age, education, marital status, diabetes, hypertension, depressive symptoms, smoking, BMI	Physically active lower prevalence of CI vs. inactive – 8.5 vs. 16.7% 0.65 OR (0.53–0.80)

M, men; F, female; CI, individuals with cognitive impairment; GCF, global/general cognitive functioning; SP, speed processing; HS, high school; ML, midlife.