The purpose of this study was to assess the impact of 24 wk of resistance training at two different intensities on cognitive functions in the elderly. Sixty-two elderly individuals were randomly assigned to three groups: CONTROL (N = 23), experimental moderate (EMODERATE; N = 19), and experimental high (EHIGH; N = 20). The volunteers were assessed on physical, hemodynamic, cognitive, and mood parameters before and after the program. On the 1 RM test (P < 0.001), the two experimental groups performed better than the CONTROL group, but they did not show differences between themselves. The EHIGH group gained more lean mass (P = 0.05) than the CONTROL group and performed better on the following tests: digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.001), similarities (P = 0.03), Rey-Osterrieth complex figure immediate recall (P = 0.02), Toulouse-Pieron concentration test errors (P = 0.01), SF-36 (general health) (P = 0.04), POMS (tension-anxiety, P = 0.04; depression-dejection, P = 0.03; and total mood disorder, P = 0.03). The EMODERATE group scored higher means than the CONTROL group on digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.01), similarities (P = 0.02), Rey-Osterrieth complex figure immediate recall (P = 0.02), SF-36 (general health, P = 0.005; vitality, P = 0.006), POMS (tension-anxiety, P = 0.001; depression-dejection, P = 0.006; anger-hostility, P = 0.006; fatigue-inertia, P = 0.02; confusion-bewilderment, P = 0.02; and total mood disorder, P = 0.001). We also found that IGF-1 serum levels were higher in the experimental groups (EMODERATE, P = 0.02; EHIGH, P < 0.001). Moderate- and high-intensity resistance exercise programs had equally beneficial effects on cognitive functioning.

As aging advances, changes in mood and anxiety may imply greater risk of mood disorders, particularly anxiety and depression. Resistance exercise reduces anxiety and lessens risk of depression in the elderly, but little is known of the mechanisms involved. It was hypothesized that the human growth factor (IGF-1) may improve mood and anxiety in elderly participants given resistance training. 43 elderly men ages 65 to 75 years were randomly assigned to two groups, Control (n = 23) and high resistance Exercise (n = 20). After 24 wk., the Exercise group showed improved muscular strength and higher IGF-1 serum levels than the Control group, as indicated by mean scores on a visual analogue mood scale and the State-Trait Anxiety Inventory. Intensive resistance training was efficacious in improving mood, anxiety, and IGF-1 serum concentration in elderly individuals free of clinical mood disorders.

Key words: Physical exercise; IGF-1; BDNF; IGFBP-3; schizophrenia; resistance exercise; concurrent exercise