Page 1 of 17 Progressive Resistance Exercise in Parkinson’s Disease Lamotte et al. http://dx.doi.org/10.1123/kr.2014-0074 Lamotte is with the Department of Neurology, University Hospital of Caen, Caen, France. Skender is with the Department of Kinesiology and Nutrition, University of Illinois at Chicago, IL. Rafferty is with the Graduate Program in Neuroscience, University of Illinois at Chicago, IL, and the Department of Physical Therapy & Human Movement Sciences, Northwestern University, Chicago, IL. David, Sadowsky, and Corcos are with the Department of Physical Therapy & Human Movement Sciences, Northwestern University, Chicago, IL. Corcos is also with the Department of Neurological Sciences, Rush University Medical Center, Chicago, IL. [AUQ1] Effects of Progressive Resistance Exercise Training on the Motor and Nonmotor Features of Parkinson’s Disease: A Review Guillaume Lamotte, Elizabeth Skender, Miriam R. Rafferty, Fabian David, Steve Sadowsky, and Daniel M. Corcos Objective: This paper reviews the therapeutically beneficial effects of progressive resistance exercise training (PRET) on motor and nonmotor symptoms in Parkinson’s disease (PD). Methods: First, we perform a systematic review of the literature on the effects of PRET on motor signs of PD, functional outcomes, quality of life, and patient perceived improvement, strength, and cognition in PD. Second, we perform a meta-analysis on the motor section of the UPDRS. Finally, we discuss the results of our review and we identify current knowledge gaps regarding PRET in PD. Conclusion: This systematic review synthesizes evidence that PRET can improve strength and motor signs of Parkinsonism in PD and may also be beneficial for physical function in individuals with PD. Further research is needed to explore the effects of PRET on nonmotor symptoms such as depression, cognitive impairment, autonomic nervous system dysfunction, and quality of life in individuals with PD. Keywords: Parkinson’s disease, progressive resistance exercise, exercise, resistance exercise, motor activity, gait, balance Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor symptoms such as bradykinesia, rigidity, tremor, gait dysfunction, and postural instability, as well as nonmotor symptoms such as cognitive impairment and mood disorders, among others. Symptoms of PD worsen with time, leading to a general decrease in activity and an altered quality of life with increased risk of falling, immobility, and cognitive impairment (Morris, Huxham, McGinley, Dodd, & Iansek, 2001; Olanow, Stern, & Sethi, 2009). To date, there is no neuroprotective strategy available for PD. Consequently, there is a need for new therapies that can slow disease progression and reduce the functional and cognitive declines seen with advancement of the disease. Epidemiological studies have supported a link between moderate to vigorous exercise habits in midlife and the reduced risk of later developing PD (Chen, Zhang, Schwarzschild, Hernán, & Ascherio, 2005; Xu et al., 2010). Recently, the American College of Sports Medicine issued new guidelines to promote exercise in older adults (Garber et al., 2011). According to these recommendations, older adults should exercise regularly and combine endurance exercise training and muscle strengthening activities (Garber et al., 2011). We recently reviewed the literature on the effect of endurance exercise training in PD (Lamotte et al., 2014). This review will synthesize the literature that has examined the effects of progressive resistance exercise training (PRET) on the motor and nonmotor signs of PD. PRET can be defined as a method of exercise that systematically and progressively increases the ability of muscle to generate force (Taylor, Dodd, & Damiano, 2005). PRET is based on three principles: (1) to perform a small number of repetitions until fatigue, (2) to allow sufficient rest between exercises for recovery, and (3) to increase the resistance as the ability to generate force increases (Taylor, Dodd, & Damiano, 2005). Several studies have shown that patients with PD have reduced muscle strength compared with controls (Allen, Canning, Sherrington, & Fung, 2009; Cano-de-la-Cuerda, Perez-de-Heredia, Miangolarra-Page, Munoz-Hellin, & Fernandez-de-Las-Penas, 2010). The fact that muscle weakness and bradykinesia may share common underlying mechanisms involving a dysfunction of the nigrostriatal pathway that alters corticospinal activation supports the use of PRET in this population (David et al., 2012). PRET has been established as a safe form of exercise, and a recent meta-analysis depicted PRET as having a moderate positive effect on strength and