Dina Christina Janse van Rensburg

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AIM To determine if there is a difference between autonomic cardiac control as measured by heart rate variability (HRV) in women with rheumatoid arthritis (RA) compared to a healthy control group. METHODS The RA group (45) and control group (39) were matched for age and body mass index (BMI). Three techniques were used: time domain, frequency domain and(More)
The study investigated whether supine-measured HRV indicators, and/or HRV indicators measured during orthostatic stress are related to conventional measures of exercise and performance ability such as VO(2max). Only two significant correlations (p<0.05) out of 30 tests were found between supine-determined HRV indicators and conventional measures. In(More)
BACKGROUND Exercise-associated muscle cramping (EAMC) is a significant medical complication in distance runners, yet factors associated with EAMC are poorly documented. OBJECTIVE To document risk factors associated with EAMC in runners. DESIGN Cross-sectional study. SETTING Two ocean races (21.1 km, and 56 km). PARTICIPANTS Fifteen thousand seven(More)
A 28-year-old male rugby player presented with severe onset of right hip pain when he fell awkward after a ruck during an international match. A rare case of an acute strain of the obturator internus muscle, a deep muscle of the hip joint, is reported, which resolved completely after a period of rest and intense active physical therapy.
South Africa hosts two of the world’s largest individually timed one day cycle races with approximately 35 000 cyclists per race. Despite the fact that these events are major international drawcards and that cycling is a popular recreational activity globally, there is limited research on the use of nutrition and supplements in amateur cyclists. Most(More)
Grant, CC, Mongwe, L, Janse van Rensburg, DC, Fletcher, L, Wood, PS, Terblanche, E, and du Toit, PJ. The difference between exercise-induced autonomic and fitness changes measured after 12 and 20 weeks of medium-to-high intensity military training. J Strength Cond Res 30(9): 2453-2459, 2016-The aim of this study was to compare the physical fitness, based on(More)
Clay-shoveler fracture is a fracture of the spinous process of lower cervical and upper thoracic vertebrae. It has only rarely been reported as being caused by an overuse sports injury. This case report describes the first reported clay-shoveler fracture in a paddler. A 51-year-old male paddler, preparing for a paddling adventure over 630 km, felt a click(More)
OBJECTIVE To describe the incidence and patterns of injury and illness of male and female participants during a 94.7 km distance cycling event. DESIGN Descriptive study. SETTING Momentum 94.7 Cycle Challenge 2014. PARTICIPANTS All 23 055 race starters (males = 17 520, females = 5236, not specified = 299). MAIN OUTCOME MEASURES The incidence and type(More)
BACKGROUND The effect of exercise interventions on autonomic nervous system (ANS) control of the heart by heart rate variability (HRV) is often investigated in just one position. It was hypothesized that results of exercise-induced changes on ANS are dependent on body position and that it is possible to distinguish between exercise induced changes in vagal(More)