Caffeine gum and cycling performance: a timing study.

The purpose of this study was to determine the most efficacious time to administer caffeine (CAF) in chewing gum to enhance cycling performance. Eight male cyclists participated in 5 separate laboratory sessions. During the first visit, the subjects underwent a graded exercise test to determine maximal oxygen consumption (V[Combining Dot Above]O(2)max). During the next 4 visits, 3 pieces of chewing gum were administered at 3 time points (120-minute precycling, 60-minute precycling, and 5-minute precycling). In 3 of the 4 visits, at 1 of the time points mentioned previously, 300 mg of CAF was administered. During the fourth visit, placebo gum was administered at all 3 time points. The experimental trials were defined as follows: trial A (-120), trial B (-60), trial C (-5), and trial D (Placebo). After baseline measurements, time allotted for gum administration, and a standard warm-up, the participants cycled at 75% V[Combining Dot Above]O(2)max for 15 minutes then completed a 7-kJ·kg(-1) cycling time trial. Data were analyzed using a repeated measures analysis of variance. Cycling performance was improved in trial C (-5), but not in trial A (-120) or trial B (-60), relative to trial D (Placebo). CAF administered in chewing gum enhanced cycling performance when administered immediately prior, but not when administered 1 or 2 hours before cycling.

Active-assisted cycling improves tremor and bradykinesia in Parkinson's disease.

OBJECTIVES: To develop a rapid cadence cycling intervention (active-assisted cycling [AAC]) using a motorized bike and to examine physiological perimeters during these sessions in individuals with Parkinson's disease (PD). A secondary goal was to examine whether a single session of AAC at a high cadence would promote improvements in tremor and bradykinesia similar to the on medication state. DESIGN: Before-after pilot trial with cross-over. SETTING: University research laboratory. PARTICIPANTS: Individuals with idiopathic PD (N=10, age 45-74y) in Hoehn and Yahr stages 1 to 3. INTERVENTION: Forty minutes of AAC. MAIN OUTCOME MEASURES: Heart rate, pedaling power, and rating of perceived exertion were recorded before, during, and after a bout of AAC. Functional assessments included tremor score during resting, postural, and kinetic tremor. RESULTS: This AAC paradigm was well tolerated by individuals with PD without excessive fatigue, and most participants showed improvements in tremor and bradykinesia immediately after a single bout of cycling. CONCLUSIONS: This paradigm could be used to examine changes in motor function in individuals with PD after bouts of high-intensity exercise.

Acute effects of passive leg cycling on upper extremity tremor and bradykinesia in Parkinson's disease.

BACKGROUND: Previous studies have shown that single bouts of high-rate active cycling (> 80 rpm) improve upper extremity motor function in individuals with Parkinson's disease (PD). It is unknown if passive leg cycling produces a similar effect on upper extremity function. This article examines whether passive leg cycling can promote immediate changes in upper tremor and bradykinesia in PD and if pedaling rates have variable effects. METHODS: Twenty individuals with mild-to-moderate idiopathic PD completed 4 sessions, with each session taking place 1 week apart. In the second to fourth sessions, a motorized bicycle was set to passively rotate the subjects' legs at rates of 60, 70, or 80 rpm for 30 minutes. Quantitative upper extremity motor assessments were completed immediately before and after each session. RESULTS: Passive leg cycling was shown to reduce tremor and bradykinesia in PD. However, the rate of passive cycling did not affect the degree of improvement in bradykinesia or tremor. CONCLUSION: These findings suggest that lower extremity passive cycling can promote changes in upper extremity motor function in individuals with PD.

Changes in executive function after acute bouts of passive cycling in Parkinson's disease.

Individuals with Parkinson's disease (PD) often experience cognitive declines. Although pharmacologic therapies are helpful in treating motor deficits in PD, they do not appear to be effective for cognitive complications. Acute bouts of moderate aerobic exercise have been shown to improve cognitive function in healthy adults. However, individuals with PD often have difficulty with exercise. This study examined the effects of passive leg cycling on executive function in PD. Executive function was assessed with Trail-Making Test (TMT) A and B before and after passive leg cycling. Significant improvements on the TMT-B test occurred after passive leg cycling. Furthermore, the difference between times to complete the TMT-B and TMT-A significantly decreased from precycling to postcycling. Improved executive function after passive cycling may be a result of increases in cerebral blood flow. These findings suggest that passive exercise could be a concurrent therapy for cognitive decline in PD.