Repeatability of a running heat tolerance test.

At present there is no standardised heat tolerance test (HTT) procedure adopting a running mode of exercise. Current HTTs may misdiagnose a runner's susceptibility to a hyperthermic state due to differences in exercise intensity. The current study aimed to establish the repeatability of a practical running test to evaluate individual's ability to tolerate exercise heat stress. Sixteen (8M, 8F) participants performed the running HTT (RHTT) (30 min, 9 km h(-1), 2% elevation) on two separate occasions in a hot environment (40 °C and 40% relative humidity). There were no differences in peak rectal temperature (RHTT1: 38.82 ± 0.47 °C, RHTT2: 38.86 ± 0.49 °C, Intra-class correlation coefficient (ICC)=0.93, typical error of measure (TEM) = 0.13 °C), peak skin temperature (RHTT1: 38.12 ± 0.45, RHTT2: 38.11 ± 0.45 °C, ICC = 0.79, TEM = 0.30 °C), peak heart rate (RHTT1: 182 ± 15 beats min(-1), RHTT2: 183 ± 15 beats min(-1), ICC = 0.99, TEM = 2 beats min(-1)), nor sweat rate (1721 ± 675 g h(-1), 1716 ± 745 g h(-1), ICC = 0.95, TEM = 162 g h(-1)) between RHTT1 and RHTT2 (p>0.05). Results demonstrate good agreement, strong correlations and small differences between repeated trials, and the TEM values suggest low within-participant variability. The RHTT was effective in differentiating between individuals physiological responses; supporting a heat tolerance continuum. The findings suggest the RHTT is a repeatable measure of physiological strain in the heat and may be used to assess the effectiveness of acute and chronic heat alleviating procedures.

Limitations to high intensity exercise prescription in chronic heart failure patients.

BACKGROUND: Interval training is recommended for chronic heart failure patients (CHF), but specific guidelines on setting appropriate workloads have not been fully established. The aim of this study was to compare a traditional method of interval training prescription with a protocol specifically designed for CHF. METHODS: Ten CHF and 7 healthy controls performed 2 maximal incremental cycle tests to determine interval training workload; a standard test (10Wmin(-)(1)) and a steep test (25W.10(-)(s)). Peak work rate and oxygen uptake (VO(2 peak)) were determined. Training workloads were defined as 100% standard test and 50% steep test peak work rate. RESULTS: Training workload determined from the standard test was higher than from the steep test in healthy controls (151 ± 17W vs 118 ± 13W; P<0.01), whereas in CHF there was no significant difference between methods (88 ± 10W vs 96 ± 9W; P>0.05). Steep test VO(2peak) reached 91 ± 5% of standard test VO(2 peak) in controls, and 99 ± 4% in CHF, with no significant differences between tests in either group. CONCLUSION: Prescribing interval training from a standard test results in higher workloads than from a steep test in healthy individuals, but in CHF both methods prescribe similar workloads. However it should not be assumed that the two tests can be used interchangeably for CHF. This small-sized study raises issues about interval training prescription that may be hypothesis-generating for future larger-scale studies.

A randomized controlled trial investigating the efficiency of musculoskeletal physiotherapy on chronic low back disorder.

STUDY DESIGN: Randomized, single blind, controlled trial. OBJECTIVE: To determine the efficacy of 2 components of musculoskeletal physiotherapy on chronic low back disorder. SUMMARY OF BACKGROUND DATA: Musculoskeletal physiotherapy encompasses many treatment methods, however, manual therapy and exercises to rehabilitate spinal stabilization are the most frequently used. Despite their popularity, scant evidence supports their use on subjects with chronic low back disorder. METHODS: A total of 346 subjects were randomized to manual therapy, a 10-week spinal stabilization rehabilitation program, or a minimal intervention control group. Data were collected at baseline, and 3, 6, 12, and 24 months after intervention. Outcome measures recorded intensity of low back pain, disability, handicap, medication, and quality of life. There were 4 main variables combined in a primary component analysis to form a single outcome measure (i.e., a measure of dysfunction). RESULTS: The results indicated statistically significant improvements in favor of the spinal stabilization group at the 6-month stage in pain (65.9% reduction in symptoms) and dysfunction (combined mean reduction of 134, standard error 23.84), and at the 1-year stage in medication (34.3% reduction in medication), dysfunction (combined mean reduction of 134, standard error 18.2), and disability (mean difference in change 15.71 Oswestry Disability Index, 95% confidence interval 19.3-10.01). CONCLUSIONS: As a component of musculoskeletal physiotherapy, the spinal stabilization program is more effective than manually applied therapy or an education booklet in treating chronic low back disorder over time. Both manual therapy and the spinal stabilization program are significantly effective in pain reduction in comparison to an active control. To our knowledge and up until now, this result has not been shown in patients with chronic low back disorder.