Gait impairment in Parkinson's disease (PD) patients is characterized by the inability to generate appropriate stride length. Treadmill training has been proposed as a therapeutic tool for PD patients. However, it remains unknown whether treadmill training effects are different from overground walking training. Thus, our goal was to explore the effects of two training programs, walking on a treadmill and walking overground, in PD patients. 22 PD patients were randomly assigned to a treadmill or overground training group. The training program consisted of 5 weeks (3 sessions/week). Before and after the program we evaluated gait kinematics during walking at preferred and maximal speed; Timed Up and Go (TUG); static posturography and knee extensors strength. Gait parameters were reevaluated in the treadmill training group one month after the cessation of the training. Preferred speed walking improved in both groups after the training program. The treadmill training program, but not the overground, led to an improvement in the stride length at the preferred and maximal walking speed in the PD patients. In addition, the treadmill training group showed improvement of the TUG and static posturography tests. The improvement in gait parameters was maintained one month after the cessation of the treadmill training. This study provides evidence of a specific therapeutic effect of treadmill training on Parkinsonian gait and balance. Walking on a treadmill may be used as an easy, effective and accessible way to improve the stride length and balance in PD patients.

Repetitive, monotonic, and effortful voluntary muscle contractions performed for just a few weeks, i.e., resistance training, can substantially increase maximal voluntary force in the practiced task and can also increase gross motor performance. The increase in motor performance is often accompanied by neuroplastic adaptations in the central nervous system. While historical data assigned functional relevance to such adaptations induced by resistance training, this claim has not yet been systematically and critically examined in the context of motor performance across the lifespan in health and disease. A review of muscle activation, brain and peripheral nerve stimulation, and imaging data revealed that increases in motor performance and neuroplasticity tend to be uncoupled, making a mechanistic link between neuroplasticity and motor performance inconclusive. We recommend new approaches, including causal mediation analytical and hypothesis-driven models to substantiate the functional relevance of resistance training-induced neuroplasticity in the improvements of gross motor function across the lifespan in health and disease.

The purpose of the present systematic review and meta-analysis was to explore the effects of transcranial direct current stimulation (tDCS) on endurance (i.e., time to task failure (TTF)) and maximal voluntary contraction (MVC). Furthermore, we aimed to analyze whether the duration of stimulation, the brain region targeted for stimulation, and the task performed could also influence motor performance. We performed a systematic literature review in the databases MEDLINE and Web of Science. The short-term effects of anodal tDCS and sham stimulation (placebo) were considered as experimental and control conditions, respectively. A total of 31 interventions were included (MVC = 13; TTF = 18). Analysis of the strength-related tDCS studies showed small improvements in the MVC (SMD = 0.19; 95% CI = −0.02, 0.41; p = 0.08). However, the results of the endurance-related interventions indicated a moderate effect on TTF performance (SMD = 0.26; 95% CI = 0.07, 0.45; p = 0.008). Furthermore, the sub-analysis showed that anodal tDCS over M1 and stimulation durations longer than 10 min produced the best results in terms of TTF performance enhancement. Additionally, the effects of anodal tDCS were larger during full body exercises (i.e., cycling) when compared to uniarticular tasks. In conclusion, the current meta-analysis indicated that anodal tDCS leads to small and moderate effects on MVC and TTF, respectively.

González-Hernández, JM, García-Ramos, A, Castaño-Zambudio, A, Capelo-Ramírez, F, Marquez, G, Boullosa, D, and Jiménez-Reyes, P. Mechanical, metabolic, and perceptual acute responses to different set configurations in full squat. J Strength Cond Res 34(6): 1581–1590, 2020—This study aimed to compare mechanical, metabolic, and perceptual responses between 2 traditional (TR) and 4 cluster (CL) set configurations. In a counterbalanced randomized order, 11 men were tested with the following protocols in separate sessions (sets × repetitions [interrepetition rest]): TR1: 3 × 10 [0 seconds]; TR2: 6 × 5 [0 seconds]; CL1: 3 × 10 [10 seconds]; CL2: 3 × 10 [15 seconds]; CL3: 3 × 10 [30 seconds]; CL4: 1 × 30 [15 seconds]. The exercise (full squat), number of repetitions (30), interset rest (5 minutes), and resistance applied (10 repetition maximum) was the same for all set configurations. Mechanical fatigue was quantified by measuring the mean propulsive velocity during each repetition and the change in countermovement jump height observed after each set and after the whole training session. Metabolic and perceptual fatigue were assessed via the blood lactate concentration and the OMNI perceived exertion scale measured after each training set, respectively. The mechanical, metabolic, and perceptual measures of fatigue were always significantly higher for the TR1 set configuration. The 2 set configurations that most minimized the mechanical measures of fatigue were CL2 and CL3. Perceived fatigue did not differ between the TR2, CL1, CL2, and CL3 set configurations. The lowest lactate concentration was observed in the CL3 set configuration. Therefore, both the CL2 and CL3 set configurations can be recommended because they maximize mechanical performance. However, the CL2 set configuration presents 2 main advantages with respect to CL3 (a): it reduces training session duration, and (b) it promotes higher metabolic stress, which, to some extent, may be beneficial for inducing muscle strength and hypertrophy gains.