When encouraged to walk at a comfortable pace for up to 50 minutes and perform stretching-and-resistance exercises, patients experienced improvements in gait speed, mobility, and cardiovascular fitness.
HONOLULU—Low-intensity treadmill training was more effective than high-intensity treadmill training, which included increasing velocity and incline, in improving motor symptoms of Parkinson’s disease, researchers reported at the 63rd Annual Meeting of the American Academy of Neurology.
Lisa M. Shulman, MD, Professor of Neurology at the University of Maryland School of Medicine in Baltimore, led an investigation to determine the efficacy of three different models of exercise to improve gait and mobility in patients with Parkinson’s disease. “Although it makes sense to look at exercise as possibly being efficacious for these problems,” Dr. Shulman said, “there really has been relatively little focus over the years in nonpharmacologic interventions like exercise.”
The investigators conducted a randomized, single-blinded clinical trial with three models of exercise: treadmill training with aerobic exercise (high-intensity exercise), treadmill training without aerobic exercise (low-intensity exercise), and stretching-and-resistance exercise.
Sixty-seven patients in total were included in the study; 22 or 23 participants were randomized to each exercise arm of the study. The participants’ mean age was 66, and the average time since symptom onset was about 6 years. Patients were randomized to one of the three regimens and were asked to perform training three times a week for three months.
Patients Increased Intensity and Duration of Exercise Throughout Training Period
Patients randomized to the high-intensity treadmill training group, Dr. Shulman explained, started the training by walking for 15 minutes each session. As the training progressed, they were encouraged to increase their duration, velocity, and incline until they reached 30 minutes per training period at 70% to 80% of their heart rate reserve.
Similarly, those randomized to the low-intensity training group began at 15 minutes and were encouraged to increase their duration until they reached a target time of 50 minutes at 40% to 50% of their heart rate reserve. Dr. Shulman noted, “It was less intense in terms of the aerobic stimulus; there wasn’t incline of velocity, but it was longer in duration.”
Those in the stretching-and-resistance group performed muscle-strengthening and stretching exercises on the upper and lower body. Patients were also encouraged to increase the amount of weight they used in resistance exercises to manage their muscle-strengthening progression.
Exercise Was Not Efficacious in Reducing Nonmotor Symptoms
The primary objective of this study was to assess the efficacy of exercise to improve gait and mobility, Dr. Shulman said. The researchers used the distance that patients could walk for a period of six minutes as the primary outcome measure. “The lower-intensity treadmill group and the stretching-and-resistance group had significant improvements in their distance,” Dr. Shulman reported, “whereas the high-intensity group had a trend of improvement but did not reach statistical significance. Overall, the low-intensity treadmill group had the most consistent improvements in all of the gait-speed measures.”
The investigators also examined the effects of exercise in improving cardiovascular fitness and found significant improvements in both treadmill groups, but not in the stretching-and-resistance group. Stretching-and-resistance training was, however, the only type of training that improved parkinsonian symptoms per the Unified Parkinson’s Disease Rating Scale motor score.
“Somewhat surprisingly, there were no improvements on a range of nonmotor outcomes following the three months of training,”
Dr. Shulman reported. These nonmotor symptoms include depression, apathy, fatigue, quality of life, and fall self-efficacy, or the patient’s confidence that he or she can prevent or manage falls. The researchers also underestimated the efficacy of the stretching-and-resistance exercise model, she noted, as this arm of the study resulted in improvements in the six-minute walk that exceed the results of high-intensity gait-training.
A Combination of Exercise Models Was Most Effective for Gait, Mobility, and Cardiovascular Fitness
“Both the high- and low-intensity treadmill training resulted in improvements in gait speed, mobility, and fitness,” Dr. Shulman summarized. “But, importantly, it wasn’t necessary to greatly increase the intensity of walking to achieve these benefits.”
Although participants improved on measures of speed and mobility, these benefits did not translate to performance on daily function, which Dr. Shulman attributed to inadequate measures of daily function and disability.
She concluded, “These results suggest that the combination of low-intensity treadmill training plus stretching-and-resistance training is likely to provide the greatest range of improvements for gait, mobility, and cardiovascular fitness in Parkinson’s disease.”
—Ariel Jones