The effect of three different exercise training modalities on cognitive and physical function in a healthy older population.

BACKGROUND: Older adults are encouraged to participate in regular physical activity to counter the age-related declines in physical and cognitive health. Literature on the effect of different exercise training modalities (aerobic vs resistance) on these health-related outcomes is not only sparse, but results are inconsistent. In general, it is believed that exercise has a positive effect on executive cognitive function, possibly because of the physiological adaptations through increases in fitness. Indications are that high-intensity interval training is a potent stimulus to improve cardiovascular fitness, even in older adults; however, its effect on cognitive function has not been studied before. Therefore, the purpose of this study was to compare the effects of resistance training, high-intensity aerobic interval training and moderate continuous aerobic training on the cognitive and physical functioning of healthy older adults. METHODS: Sixty-seven inactive individuals (55 to 75 years) were randomly assigned to a resistance training (RT) group (n = 22), high-intensity aerobic interval training (HIIT) group (n = 13), moderate continuous aerobic training (MCT) group (n = 13) and a control (CON) group (n = 19) for a period of 16 weeks. Cognitive function was assessed with a Stroop task and physical function with the Timed-Up-and-Go (TUG) and submaximal Bruce treadmill tests. RESULTS: No significant GROUP x TIME interaction was found for Stroop reaction time (P > .05). The HIIT group showed the greatest practical significant improvement in reaction time on the information processing task, i.e. Stroop Neutral (ES = 1.11). MCT group participants had very large practical significant improvements in reaction time on the executive cognitive tasks, i.e. Stroop Incongruent and Interference (ES = 1.28 and 1.31, respectively). The HIIT group showed the largest practically significant increase in measures of physical function, i.e. walking endurance (ES = 0.91) and functional mobility (ES = 0.36). CONCLUSIONS: MCT and RT proved to be superior to HIIT for the enhancement of older individuals' executive cognitive function; whereas HIIT were most beneficial for improvement in information processing speed. HIIT also induced the largest gains in physical function.

Cerebral oxygenation during cortical activation: the differential influence of three exercise training modalities. A randomized controlled trial.

PURPOSE: To determine if a cerebral oxygenation response during cortical activation is influenced by exercise training mode. METHODS: Sixty-seven individuals (55-75 years old) volunteered for this 16-week intervention study. Participants were randomized into a resistance training (RT) group (n = 22), high-intensity interval training (HIIT) group (n = 13), moderate continuous training (MCT) group (n = 13) and a control (CON) group (n = 19). Near-infrared spectroscopy was used to measure cerebral oxygenation during the Stroop task. A submaximal Bruce treadmill test was used to measure changes in walking endurance. RESULTS: The GROUP × TIME interaction for reaction time on the naming and executive Stroop conditions were not significant (P > 0.05). At post-test, the CON group showed increased brain activation, with significantly higher relative oxy-haemoglobin (O2Hb) values during the naming Stroop condition compared to pre-test (P = 0.03), while their increased relative O2Hb on the complex condition showed a distinct trend toward significance (P = 0.09). MCT and HIIT participants exhibited decreased brain activation during the Stroop task, with MCT showing a significant increase in relative deoxy-haemoglobin (HHb) compared to pre-test during the naming and executive Stroop conditions (P < 0.05). The HIIT group improved significantly in walking endurance (P = 0.04). CONCLUSION: Sixteen weeks of exercise training resulted in more efficient cerebral oxygenation during cortical activation compared to a no-exercise control group. Furthermore, HIIT and MCT were superior to RT for task-efficient cerebral oxygenation and improved oxygen utilization during cortical activation in older individuals.

The time course of changes induced by resistance training and detraining on muscular and physical function in older adults.

BACKGROUND: It is generally recognised that the physical functioning of older adults is enhanced with resistance exercise. The aim of this study was to investigate the time course of changes in upper and lower body muscle strength and physical function in older individuals following a 16 week resistance training (RT) programme and a similar duration detraining (DET) period. METHODS: Forty-one inactive individuals (55 to 75 years) were randomly allocated in a RT group (n = 22; three sessions per week) and a control (CON) group (n = 19). Muscle strength was assessed with 10RM leg and bench press tests, while the Timed-Up-and-Go (TUG) test was used to measure functional mobility. The Bruce treadmill test determined the participants' submaximal endurance capacity. Data were analysed using mixed model repeated measures ANOVA and P < 0.05 was considered statistically significant. RESULTS: Main treatment effects were found for muscle strength (P < 0.001) and functional mobility (P < 0.05). Upper and lower body strength generally showed a statistically significant improvement after every 4 weeks in RT (the increase after 16 weeks being 7.3 ± 4.9 kg and 86.6 ± 44.4 kg, respectively; P < 0.001) while TUG performance (-0.2 ± 0.4 s; P < 0.05) and submaximal endurance capacity (0.7 ± 0.9 min; P < 0.001) only improved after 16 weeks. Although muscle strength decreased after DET, it was still better than at baseline. No significant improvements in any performance variable were observed in CON directly after the intervention period (0-16 weeks) (P > 0.05). CONCLUSION: A 16-week RT programme has positive effects on both muscular and physical function in older adults, although the time course of these adaptations is different. While the gains in muscle strength and submaximal endurance capacity were not totally lost after DET, functional mobility was completely reversed. Older adults can be reassured that if the need arises to discontinue RT for a certain period they will still retain a large amount of their acquired muscle strength, as well as a degree of physical function such as submaximal endurance capacity. The association between leg strength and submaximal endurance capacity strengthens the notion that RT should be incorporated in training and rehabilitation programmes of ageing and frail older adults.