Ginger has known hypoalgesic and anti-inflammatory properties. The effects of an oral dose of ginger on quadriceps muscle pain, rating of perceived exertion (RPE), and recovery of oxygen consumption were examined during and after moderateintensity cycling exercise. Twenty-five college-age participants ingested a 2-g dose of ginger or placebo in a double-blind, crossover design and 30 min later completed 30 min of cycling at 60% of VO2peak. Quadriceps muscle pain, RPE, work rate, heart rate (HR), and oxygen uptake (VO2) were recorded every 5 min during exercise, and HR and VO2 were recorded for 20 min after exercise. Compared with placebo, ginger had no clinically meaningful or statistically significant effect on perceptions of muscle pain, RPE, work rate, HR, or VO2 during exercise. Recovery of VO2 and HR after the 30-min exercise bout followed a similar time course in the ginger and placebo conditions. The results were consistent with related findings showing that ingesting a large dose of aspirin does not acutely alter quadriceps muscle pain during cycling, and this suggests that prostaglandins do not play a large role in this type of exercise-induced skeletal-muscle pain. Ginger consumption has also been shown to improve VO2 recovery in an equine exercise model, but these results show that this is not the case in humans.
Christopher D. Black and Patrick J. O’Connor
Nathan T. Jenkins, Jennifer L. Trilk, Arpit Singhal, Patrick J. O’Connor and Kirk J. Cureton
The purpose of this experiment was to learn whether low doses of caffeine have ergogenic, perceptual, and metabolic effects during cycling. To determine the effects of 1, 2, and 3 mg/kg caffeine on cycling performance, differentiated ratings of perceived exertion (D-RPE), quadriceps pain intensity, and metabolic responses to cycling exercise, 13 cyclists exercised on a stationary ergometer for 15 min at 80% VO2peak, then, after 4 min of active recovery, completed a 15-min performance ride 60 min after ingesting caffeine or placebo. Work done (kJ/kg) during the performance ride was used as a measure of performance. D-RPE, pain ratings, and expired-gas data were obtained every 3 min, and blood lactate concentrations were obtained at 15 and 30 min. Compared with placebo, caffeine doses of 2 and 3 mg/kg increased performance by 4% (95% CI: 1.0–6.8%, p = .02) and 3% (95% CI: –0.4% to 6.8%, p = .077), respectively. These effects were ergogenic, on average, but varied considerably in magnitude among individual cyclists. There were no effects of caffeine on D-RPE or pain throughout the cycling task. Selected metabolic variables were affected by caffeine, consistent with its known actions. The authors conclude that caffeine preparations of 2 and 3 mg/kg enhanced performance, but future work should aim to explain the considerable interindividual variability of the drug’s ergogenic properties.
Patrick J. O’Connor, Amanda L. Caravalho, Eric C. Freese and Kirk J. Cureton
Compounds found in the skins of grapes, including catechins, quercetin, and resveratrol, have been added to the diet of rodents and improved run time to exhaustion, fitness, and skeletal-muscle mitochondrial function. It is unknown if such effects occur in humans. The purpose of this experiment was to investigate whether 6 wk of daily grape consumption influenced maximal oxygen uptake (VO2max), work capacity, mood, perceived health status, inflammation, pain, and arm-function responses to a mild eccentric-exercise-induced arm-muscle injury. Forty recreationally active young adults were randomly assigned to consume a grape or placebo drink for 45 consecutive days. Before and after 42 d of supplementation, assessments were made of treadmill-running VO2max, work capacity (treadmill performance time), mood (Profile of Mood States), and perceived health status (SF-36 Health Survey). The day after posttreatment treadmill tests were completed, 18 high-intensity eccentric actions of the nondominant elbow flexors were performed. Arm-muscle inflammation, pain, and function (isometric strength and range of motion) were measured before and on 2 consecutive days after the eccentric exercise. Mixed-model ANOVA showed no significant effect of grape consumption on any of the outcomes. Six weeks of supplemental grape consumption by recreationally active young adults has no effect on VO2max, work capacity, mood, perceived health status, inflammation, pain, or physical-function responses to a mild injury induced by eccentric exercise.
Patrick J. O’Connor, Louis E. Aenchbacher III and Rod K. Dishman
Exercise is often recommended to elderly persons for enhancing both physical and mental health. This paper reviews the scientific evidence relating physical activity and reduced depression in the elderly. Population based studies and experimental investigations are summarized and critically evaluated. Included is a discussion of some unique challenges that must be met in order for the relationship between depression and physical activity in the elderly to be adequately studied. The weight of the available population based survey evidence, on noninstitutionalized elderly only, suggests a moderate relationship between self-reported physical inactivity and symptoms of depression. However, there is no compelling experimental evidence that exercise per se is effective in preventing or treating depressive disorders in the elderly. Suggestions aimed at improving future research in this area are offered.
Eric C. Freese, Rachelle M. Acitelli, Nicholas H. Gist, Kirk J. Cureton, Ellen M. Evans and Patrick J. O’Connor
The purpose of this investigation was to determine whether 6 weeks of sprint interval training (SIT) is associated with changes in mood and perceived health in women at risk for developing metabolic syndrome (MetS). Physically inactive women (30–65 years) were randomized to 6 weeks of nutrition meetings and SIT (n = 23; 3 bouts/week of 4–8 30-s cycle sprints with 4-min recovery) or a nonexercise control condition (CON; n = 24). Before and after the 6-week intervention, perceived health status and mood were assessed. Clinically relevant increases in role-physical scores (ES = 0.64) and vitality (ES = 0.52) were found after 6 weeks of SIT compared with a nonexercise control group. For middle-aged women at risk for MetS, it is concluded that high-intensity, low-volume SIT (1) increases feelings of vitality and perceptions of having fewer physical limitations and (2) does not induce mood disturbances as occurs with high-volume, high-intensity training.
Brian C. Martinson, A. Lauren Crain, Nancy E. Sherwood, Marcia G. Hayes, Nicolaas P. Pronk and Patrick J. O’Connor
To assess the representativeness of older adults recruited to a physical activity maintenance RCT by conducting sequential comparisons to characterize study sample composition changes occurring between sampling frame construction and study enrollment.
Study subjects (N = 1049) were 50 to 70 year old men and women who had increased physical activity within the past year recruited from a Midwestern managed care organization.
Those responding to an initial mailed screener differed on demographic, behavioral, and SES characteristics from those not responding. Compared with ineligibles, eligible individuals were significantly younger, more highly educated, and more likely to report improved health in the prior year. Compared with eligible individuals who did not enroll, enrollees had generally higher education and income.
Physical activity promotion programs in older adults may have limited reach and substantial volunteer bias. Additional strategies to increase the reach of physical activity interventions into the target population are needed.
Patrick J. O’Connor, Melanie S. Poudevigne, M. Elaine Cress, Robert W. Motl and James F. Clapp III
Describe safety and efficacy of a supervised, low-to-moderate intensity strength training program adopted during pregnancy among women at increased risk for back pain.
32 women adopted strength training twice per week for 12 weeks. Data on musculoskeletal injuries, symptoms, blood pressure, and the absolute external load used for 5 of 6 exercises were obtained during each session. A submaximal lumbar extension endurance exercise test was performed at weeks 5, 10, and 13.
The mean (± SD) exercise session attendance rate was 80.5% (± 11.3%). No musculoskeletal injuries occurred. Potentially adverse symptoms (eg, dizziness) were infrequent (2.1% of sessions). Repeated-measures ANOVA showed large increases in the external load across 12 weeks (all P values < .001) and the percentage increases in external load from weeks 1 to 12 were 36% for leg press, 39% for leg curl, 39% for lat pull down, 41% for lumbar extension and 56% for leg extension. Training was associated with a 14% increase in lumbar endurance. Blood pressure was unchanged following acute exercise sessions and after 12 weeks of exercise training.
The adoption of a supervised, low-to-moderate intensity strength training program during pregnancy can be safe and efficacious for pregnant women.