Influence of aerobic exercise training on the neural correlates of motor learning in Parkinson's disease individuals.

BACKGROUND: Aerobic exercise training (AET) has been shown to provide general health benefits, and to improve motor behaviours in particular, in individuals with Parkinson's disease (PD). However, the influence of AET on their motor learning capacities, as well as the change in neural substrates mediating this effect remains to be explored. OBJECTIVE: In the current study, we employed functional Magnetic Resonance Imaging (fMRI) to assess the effect of a 3-month AET program on the neural correlates of implicit motor sequence learning (MSL). METHODS: 20 healthy controls (HC) and 19 early PD individuals participated in a supervised, high-intensity, stationary recumbent bike training program (3 times/week for 12 weeks). Exercise prescription started at 20 min (+ 5 min/week up to 40 min) based on participant's maximal aerobic power. Before and after the AET program, participants' brain was scanned while performing an implicit version of the serial reaction time task. RESULTS: Brain data revealed pre-post MSL-related increases in functional activity in the hippocampus, striatum and cerebellum in PD patients, as well as in the striatum in HC individuals. Importantly, the functional brain changes in PD individuals correlated with changes in aerobic fitness: a positive relationship was found with increased activity in the hippocampus and striatum, while a negative relationship was observed with the cerebellar activity. CONCLUSION: Our results reveal, for the first time, that exercise training produces functional changes in known motor learning related brain structures that are consistent with improved behavioural performance observed in PD patients. As such, AET can be a valuable non-pharmacological intervention to promote, not only physical fitness in early PD, but also better motor learning capacity useful in day-to-day activities through increased plasticity in motor related structures.

Enhancing both motor and cognitive functioning in Parkinson's disease: Aerobic exercise as a rehabilitative intervention.

BACKGROUND: Aerobic exercise training (AET) has been shown to provide health benefits in individuals with Parkinson's disease (PD). However, it is yet unknown to what extent AET also improves cognitive and procedural learning capacities, which ensure an optimal daily functioning. OBJECTIVE: In the current study, we assessed the effects of a 3-month AET program on executive functions (EF), implicit motor sequence learning (MSL) capacity, as well as on different health-related outcome indicators. METHODS: Twenty healthy controls (HC) and 19 early PD individuals participated in a supervised, high-intensity, stationary recumbent bike-training program (3 times/week for 12 weeks). Exercise prescription started at 20 min (+5 min/week up to 40 min) based on participant's maximal aerobic power. Before and after AET, EF tests assessed participants' inhibition and flexibility functions, whereas implicit MSL capacity was evaluated using a version of the Serial Reaction Time Task. RESULTS: The AET program was effective as indicated by significant improvement in aerobic capacity in all participants. Most importantly, AET improved inhibition but not flexibility, and motor learning skill, in both groups. CONCLUSION: Our results suggest that AET can be a valuable non-pharmacological intervention to promote physical fitness in early PD, but also better cognitive and procedural functioning.

Comparison between several muscle strength and cardiorespiratory fitness indices with body composition and energy expenditure in obese postmenopausal women.

The purpose of this study was to compare the relationship of several muscle strength and cardiorespiratory fitness indices with body composition and energy expenditure in obese postmenopausal women. This was a cross-sectional study involving 72 obese postmenopausal women (age: 60.0±4.8 years; body mass index: 34.1±3.5 kg/m²). Muscle strength was determined by hand dynamometer and cardiorespiratory fitness was measured by indirect calorimetry. Muscle strength and cardiorespiratory fitness were expressed in absolute (kg and L/min, respectively) and in relative values (kg/body weight (BW) and kg/lean body mass (LBM) for muscle strength and ml/min/kg BW and ml/min kg LBM for cardiorespiratory fitness). Body composition was measured using dual energy x-ray absorptiometry. Anthropometric (waist and thigh circumference), physical activity energy expenditure and daily number of steps (SenseWear armband) as well as blood pressure were also assessed. Correlations of muscle strength and cardiorespiratory fitness indices with body composition and energy expenditure showed several similarities, however, several variations were also observed. Furthermore, our results showed that age and waist circumference were the primary independent predictors for the muscle strength indices, explaining 22-37% of the variance and % body fat and age were the primary predictors for the cardiorespiratory fitness indices, explaining 18-40% of the variance. In conclusion, the present study indicates that the different methods of expressing muscle strength and cardiorespiratory fitness may display several variations and similarities with body composition and energy expenditure associations. Therefore, interpretations of relationships between muscle strength and cardiorespiratory indices with body composition and energy expenditure factors should take in account the method used to express them.