Effect of intermittent normobaric hypoxia on aerobic capacity and cognitive function in older people

Evolution of Neuroplasticity in Response to Physical Activity in Old Age: The Case for Dancing

From animal research, it is known that combining physical activity with sensory enrichment has stronger and longer-lasting effects on the brain than either treatment alone. For humans dancing has been suggested to be analogous to such combined training. Here we assessed whether a newly designed dance training program that stresses the constant learning of new movement patterns is superior in terms of neuroplasticity to conventional fitness activities with repetitive exercises and whether extending the training duration has additional benefits. Twenty-two healthy seniors (63–80 years) who had been randomly assigned to either a dance or a sport group completed the entire 18-month study. MRI, BDNF and neuropsychological tests were performed at baseline and after 6 and 18 months of intervention. After 6 months, we found a significant increase in gray matter volume in the left precentral gyrus in the dancers compared to controls. This neuroplasticity effect may have been mediated by the increased BDNF plasma levels observed in the dancers. Regarding cognitive measures, both groups showed significant improvements in attention after 6 months and in verbal memory after 18 months. In addition, volume increases in the parahippocampal region were observed in the dancers after 18 months. The results of our study suggest that participating in a long-term dance program that requires constant cognitive and motor learning is superior to engaging in repetitive physical exercises in inducing neuroplasticity in the brains of seniors. Therefore, dance is highly promising in its potential to counteract age-related gray matter decline.

Intermittent hypoxia as a means to improve aerobic capacity in type 2 diabetes

Physical inactivity and a low maximal aerobic capacity (VO_2max) strongly predict morbidity and mortality in patients with type 2 diabetes (T2D). Patients with T2D have a reduced VO_2max when compared with healthy individuals of similar age, weight, and physical activity levels, and this lower aerobic capacity is usually attributed to a reduced oxygen delivery to the working muscles. The oxygen carrying capacity of the blood, as well as increases in cardiac output and blood flow, contribute to the delivery of oxygen to the active muscles during exercise. Hemoglobin mass (Hb mass), a key determinant of oxygen carrying capacity, is suggested to be reduced in patients with T2D following the observation of a lower blood volume (BV) in combination with normal hematocrit levels in this population. Therefore, a lower Hb mass, in addition to a reported lower BV and impaired cardiovascular response to exercise, likely contributes to the reduced oxygen delivery and VO_2max in patients with T2D. While exercise training increases Hb mass, BV, and consequently VO_2max, the majority of patients with T2D are not physically active, highlighting the need for alternative methods to improve VO_2max in this population. Exposure to hypoxia triggers the release of erythropoietin, the hormone regulating red blood cell production, which increases Hb mass and consequently BV. Exposure to mild intermittent hypoxia (IH), characterized by few and short episodes of hypoxia at a fraction of inspired oxygen ranging between 10 and 14% interspersed with cycles of normoxia, increased red blood cell volume, Hb mass, and plasma volume in patients with coronary artery disease or chronic obstructive pulmonary disease, which resulted in an improved VO_2max in both populations. We hypothesize that 12 exposures to mild IH over a period of 4weeks will increase Hb mass, BV, cardiac function, and VO_2max in patients with T2D. Therefore, exposures to mild IH may increase oxygen delivery and VO_2max without the need to perform exercise in patients with T2D.