Biomedical subjects

Rudolph H Dressendorfer

Publications and source records attributed to Rudolph H Dressendorfer.

8 recordsLinked to original sources

PubMed2005

Increased caloric intake soon after exercise in cold water.

We examined the acute effect of cold-water temperature on post-exercise energy intake (EI) for 1 h. In a randomized, crossover design, 11 men (25.6 +/- 5 y) exercised for 45 min on a submersed cycle ergometer at 60 +/- 2% VO2max in 33 degrees C (neutral) and 20 degrees (cold) water temperatures, and also rested for 45 min (control). Energy expenditure (EE) was determined using indirect calorimetry before, during, and after each condition. Following exercise or rest, subjects had free access to a standard assortment of food items of known caloric value. EE was similar for the cold and neutral water conditions, averaging 505 +/- 22 (+/- standard deviation) and 517 +/- 42 kcal, respectively (P = NS). EI after the cold condition averaged 877 +/- 457 kcal, 44% and 41% higher (P < 0.05) than for the neutral and resting conditions, respectively. Cold-water temperature thus stimulated post-exercise EI. Water temperature warrants consideration in aquatic programs designed for weight loss.

Adult↗

PubMed2005

A conceptual model of community capacity development for health promotion in the Alberta Heart Health Project.

PURPOSE: The objective of this study was to derive a conceptual model of community capacity development for health promotion based on the 5-year demonstration phase of the Alberta Heart Health Project. METHOD: Community actions associated with successful implementation and uptake of initiatives in four diverse target sites were identified by case study evaluation. RESULTS: Thirteen common elements of capacity development were found across the projects and categorized to define three primary dimensions of the process: (a) leadership that provided a driving force for implementation, (b) policy making that ensured diffusion and sustainability, and (c) use of local community resources and infrastructure. A conceptual model was constructed using these 3 dimensions and their interactions. CONCLUSION: Effective implementation of community health initiatives to promote heart health can be conceptualized as the involvement of local leadership, policy advocacy, and enhancement of existing infrastructure. The model highlights building these dimensions of community capacity development for health promotion.

Alberta↗

PubMed2005

Factors limiting maximal oxygen uptake in exertional monoparesis.

Strength and maximal oxygen uptake (VO2max) for each leg were compared in a trained multiple sclerosis (MS) patient with exertional left monoparesis. Left quadriceps strength and left leg VO2max were 22% and 30% lower, respectively, compared to the right (control) leg. Because the same O2 delivery system served each leg during exercise, VO2max of the paretic leg was not limited by cardiorespiratory factors but rather by strength and/or muscle oxidative capacity. However, training with monoparesis likely enhanced O2 extraction and aerobic work capacity of the right leg.

Adult↗

PubMed2004

Exercise and multiple sclerosis.

The pathophysiology of multiple sclerosis (MS) is characterised by fatigue, motor weakness, spasticity, poor balance, heat sensitivity and mental depression. Also, MS symptoms may lead to physical inactivity associated with the development of secondary diseases. Persons with MS are thus challenged by their disability when attempting to pursue an active lifestyle compatible with health-related fitness. Although exercise prescription is gaining favour as a therapeutic strategy to minimise the loss of functional capacity in chronic diseases, it remains under-utilised as an intervention strategy in the MS population. However, a growing number of studies indicate that exercise in patients with mild-to-moderate MS provides similar fitness and psychological benefits as it does in healthy controls. We reviewed numerous studies describing the responses of selected MS patients to acute and chronic exercise compared with healthy controls. All training studies reported positive outcomes that outweighed potential adverse effects of the exercise intervention. Based on our review, this article highlights the role of exercise prescription in the multidisciplinary approach to MS disease management for improving and maintaining functional capacity. Despite the often unpredictable clinical course of MS, exercise programmes designed to increase cardiorespiratory fitness, muscle strength and mobility provide benefits that enhance lifestyle activity and quality of life while reducing risk of secondary disorders. Recommendations for the evaluation of cardiorespiratory fitness, muscle performance and flexibility are presented as well as basic guidelines for individualised exercise testing and training in MS. Special considerations for exercise, including medical management concerns, programme modifications and supervision, in the MS population are discussed.

Exercise↗

PubMed2003

Effectiveness of cycle cross-training between competitive seasons in female distance runners.

The purpose of this study was to examine whether substituting 50% of run training volume with cycling ("cross-training") would maintain 3,000-m race time and estimated Vo(2)max in competitive female distance runners during a 5-week recuperative phase. Eleven collegiate runners were randomly assigned to either the run training-only (R) group (n = 6) or the cycle training (R/C) group (n = 5), which cross-trained on alternate days. The groups trained daily at a reduced intensity (75-80% of maximum heart rate). Training volume was similar to the competitive season (40-50 mi x wk(-1)) except that cycling represented 50% of volume for the R/C group. On follow-up, 3,000-m time was 1.4% (9 seconds) slower in the R group and 3.4% (22 seconds) slower in the R/C group. No important change in estimated Vo(2)max was found for either group. It was concluded that cycle cross-training adequately maintained aerobic performance during the recuperative phase between the cross-country and track seasons, comparable to the primary sport of running.

Adult↗

PubMed2002

Maintenance of testosterone status in fitness joggers after increased training mileage.

The primary objective was to evaluate the early effect of increased training mileage on testosterone (T) status in recreational joggers. Serum total (T(tot)) and free (T(free)) concentrations at rest, overnight urinary T(tot) excretion, and the T(tot) and T(free) responses to maximal exercise were used as indicators of T status. A group of 13 male [mean (SD) age 24.5 (2.5) years] fitness joggers [maximal oxygen consumption, VO(2max), 52.9 (4.9) ml.kg(-1).min(-1)] qualified as subjects. The training intervention consisted of a 100% increase in the habitual distance run [12 (3) miles.week(-1)] for 2 consecutive weeks, while maintaining the customary training intensity. Blood samples were obtained at rest and after maximal exercise tests, at the beginning and end of a control week of habitual jogging (baseline) and also following the 1st and 2nd weeks of the intervention. The and treadmill exercise endurance time were unchanged across sampling times. Serum T(tot) and T(free) concentrations averaged 565 (62) and 24 (2.6) ng.dl(-1), respectively, at baseline and did not change significantly. Urinary T(tot) excretion averaged 1.5 (0.21) ng.min(-1) at baseline, and also remained unchanged during the intervention. Relative increases in T(tot) (23%) and T(free) (22%) were observed following maximal exercise compared to rest ( P<0.05). However, the exercise-related increases in serum T(tot) and T(free) were not evident after adjustment for the change in plasma volume. It was concluded, that the training intervention did not alter T status in these fitness joggers.

Adult↗

PubMed2002

Performance enhancement with maintenance of resting immune status after intensified cycle training.

BACKGROUND: Unaccustomed intense endurance exercise is associated with short-term suppression of natural immunity. However, it is not established whether intensified endurance training alters resting immune status or increases the risk of upper respiratory infection (URI). PURPOSE: This study examined the effect of intensified endurance training for performance enhancement on resting immune status in nine healthy, male competitive cyclists. DESIGN: Data were collected during 4 weeks of usual training (baseline), followed by prescribed cycle training that consisted of volume-building at customary training intensity (V phase, 6 weeks), unaccustomed very high intensity interval training at 100% maximal heart rate (I phase, 18 days), and an unloading taper (U phase, 10 days). METHODS: The main performance criterion was a simulated 20 km time-trial. Aerobic capacity measures included power output at ventilatory threshold (POT(vent)) and maximal oxygen uptake (VO(2max)). Markers of immune status (lymphocyte subset counts, serum cytokine levels, and new URI cases) and physiological indicators of training stress (cycling economy, 24-hour urinary cortisol excretion, and serum testosterone concentration) were evaluated in the rested state, 36 to 44 hours postexercise, during baseline, and after each training phase. RESULTS: Time-trial performance, POT9(vent), VO(2max), and cycling economy improved significantly (p < 0.001) after the V phase, and remained higher than baseline (p < 0.001) after the I and U phases. As compared with the V phase, performance time was faster after the U phase (p < 0.01). In contrast, lymphocyte counts, cytokine levels, incidence of URI, cortisol excretion, and serum testosterone concentration were not significantly different from baseline in any phase. CONCLUSIONS: Cycling efficiency and performance improved while resting immune status was maintained throughout the 10-week training program. This study provides encouraging data in support of immunological robustness during intensified endurance training.

Adult↗

PubMed2002

Mineral metabolism in male cyclists during high-intensity endurance training.

This study examined the effects of intense endurance training on basal plasma and 24-hour urinary calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and copper (Cu) levels in 9 male competitive cyclists. The supervised training program followed a baseline period and included a volume phase (6 weeks, averaging 87% of maximal heart rate [HR(max)]), an interval phase (18 days, 100% of HR(max)), and a 10-day unloading taper. The primary training outcome measure was 20-km time-trial cycling performance. Subjects ate unrestricted diets and maintained their weight. Compared to baseline, performance improved significantly (p < .05), while mineral metabolism was not significantly different after the volume phase. However, after the interval phase, renal Ca excretion increased (p < .05) and plasma Ca fell slightly below the clinical norm. As compared to the interval phase, urinary Ca decreased (p <.05), plasma Ca increased (p < .05), and performance further improved (p < .05) after the taper. Whereas Mg, Fe, Zn, and Cu metabolism remained unchanged throughout the study, greater renal Ca excretion was associated with very high intensity interval training.

Adult↗