Despina D. Frangolias

Maximal and ventilatory threshold responses to treadmill and water immersion running

This study compared the metabolic responses of 13 endurance runners, familiar with nonweight-bearing water immersion (WI) running, at ventilatory threshold (Tvent) and maximal effort (VO2max) for both treadmill and WI running performance. Oxygen consumption (VO2), ventilation (VE), heart-rate (HR), VE/VO2, respiratory exchange ratio (RER), perceived exertion (RPE), and stride frequency (SF) were measured at Tvent and VO2max. Paired t-tests revealed higher VO2max (59.7 vs 54.6 ml.kg.-1min-1), HRmax (190 vs 175 bpm), RERmax (1.20 vs 1.10), VO2 at Tvent (46.3 vs 42.8 ml.kg.-1min-1), HR at Tvent (165 vs 152 bpm) for treadmill versus WI running, respectively. Treadmill and WI VEmax (109.0 vs 105.8 l.min-1), RPEmax (20), VE at Tvent (66.4 vs 65.7 l.min-1), RER at Tvent (0.99 vs 0.98), RPE at Tvent (13 vs 12) were similar, as were blood lactate [BLa] values obtained at 30 s (10.4 vs 9.8 mmol.l-1) and 5 min (9.7 vs 9.2 mmol.l-1) post-test. SF values over time were higher on the treadmill. The lower WI VO2max with similar peak [BLa] and lower SF values suggests that the active musculature and muscle recruitment patterns differ in WI running due to the high viscosity friction of water, and the nonweight-bearing nature of WI running.

Metabolic Responses and Mechanisms During Water Immersion Running and Exercise

SummaryThe low impact nature of exercise in the water has increased interest in this form of exercise and specifically in water running as a cross-training modality. It is used as a possible preventative and therapeutic modality for rehabilitation. The high impact nature of land running predisposes the runner to stress of the lower limbs and overuse injuries. The need to reduce impact, as well as provide a low impact or non-weight-bearing condition for rehabilitation, has led runners and their coaches to the water. This increased interest by coaches and their athletes, attending sports medicine physicians and rehabilitative professionals has stimulated research into water immersion to the neck (WI) running.Exercise in the water has long been used by rehabilitative professionals with patients who have physically debilitating conditions (i.e. arthritis, musculoskeletal disorders) as it provides a medium for even those with limited mobility to exercise and relax their muscles. Numerous comparative studies into WI running from a metabolic as well as a training perspective have been published. WI has also long been used to simulate weightlessness for the comparative study of cardiorespiratory function and thermoregulation. WI and the associated cephalad shift in blood volume has implications on exercise responses during WI running exercise. In addition, the non-weight-bearing nature of WI running also raises issues of the cross-training benefits of WI running. WI running style and prior familiarity with the activity have been found to have a direct relationship with the comparability of WI to land running. This review presents current research into WI running, training specificity and comparative physiology.

Role of exercise and nutrition status on bone mineral density in cystic fibrosis

BACKGROUND Exercise has been shown to maintain or increase bone mineral density (BMD) in non-CF populations. OBJECTIVES The purpose of our study was to elucidate the relationship between exercise, body composition and dietary intake with BMD in an adult CF population with heterogeneous disease severity. DESIGN We measured spinal (L1-4) and femoral (femoral neck) BMD by dual energy X-ray absorptiometry (DEXA) in 68 CF adults (24 female, 44 male) with a mean age 30.8(1.7) and 27.4(1.3) (range 18-55) years. We used the average BMD Z score for spine and femoral neck for analyses. Differences in disease severity, exercise capacity, physical activity level, dietary intake, body composition, body mass index (BMI), glucocorticoid use were correlated with BMD scores. Exercise capacity was defined as the maximal amount of oxygen consumed by muscles during maximal exercise (Vo2max). Vertebral and non-vertebral fracture rate were also recorded. RESULTS Fifty-seven patients were identified with low BMD (Z score < -1). Multiple linear regression identified exercise capacity and BMI as significant predictors of BMD. Later diagnosis of CF was also associated with low adult BMD. CONCLUSIONS Low BMD is common in adult CF patients. Exercise capacity and BMI are predictors of low BMD.

Metabolic responses to prolonged work during treadmill and water immersion running

The primary aim of this study was to compare the physiological responses to prolonged treadmill (TM) and water immersion to the neck (WI) running at threshold intensity. Ten endurance runners performed TM and WI running VO2max tests. Subjects completed submaximal performance tests at ventilatory threshold (Tvent) intensities under TM and WI conditions and responses at 15 and 42 minutes examined. VO2 was lower in WI (p<0.05) at maximal effort and Tvent. The Tvent VO2 intensities interpolated from the TM and WI VO2max tests were performed in both TM (i.e., TM@TM(tvent),TM@WI(tvent), corresponding to 77.6 and 71.3% respectively of TM VO2max) and WI conditions (i.e., WI@TM(tvent), WI@WI(tvent), corresponding to 85.5% and 78.2% respectively of WI VO2max). Each of the dependent variables was analyzed using a 3-way repeated measures ANOVA (2 conditions X 2 exercise intensities X 7 time points during exercise). VO2max values were significantly lower in the WI (52.4(5.1) ml.kg(-1) min(-1)) versus TM (59.7(6.5) ml.kg(-1) min(-1)) condition. VO2 during submaximal tests were similar during the TM and WI conditions. HR and [BLa] responses to exercise at and above WI(tvent) were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition. There were no statistical differences in VE responses in the 2 conditions, however as with HR and [BLa] an upward trend was noted with TM exercise over the 42 minute duration of the tests. RPE at WI(tvent) was similar for TM and WI exercise sessions, however, RPE at TM(tvent) was higher during WI compared to TM running. Cardiovascular drift was observed during prolonged TM but not WI running. Results suggest differences in metabolic responses to prolonged submaximal exercise in WI, however it can be used effectively for cross training.

Maintenance of aerobic capacity during recovery from right foot Jones fracture: a case report.

PURPOSE We sought to evaluate the effectiveness of continued training with deep water running (DWR) on the healing process from a lower leg fracture in maintaining aerobic fitness. CASE SUMMARY An elite male middle distance runner presented with a Jones fracture of the right foot. The patient opted for nonsurgical treatment. Non-weight-bearing immobilization in a cast proceeded for 14 weeks. The patient continued training by simulating land running and team land workouts with DWR. DWR was the principal mode of exercise through week 24. Physiological and race performance assessments noted a progressive and complete return to preinjury fitness and performance levels. DISCUSSION DWR can be used by competitive runners during a rehabilitative period to maintain fitness and does not impede the healing process. In developing a DWR regimen, it should be noted that the exercise heart rate when working above the ventilatory threshold will be approximately 12 bpm lower in water. RELEVANCE DWR may be feasible for maintenance of competitive edge during lower trunk injury rehabilitation.