Metabolic and cardiovascular responses during work on a high ropes course.

ABSTRACT

BACKGROUND: High ropes course facilities are employed in adventure programs to promote self-esteem, stress management, and problem-solving skill development. Although the combination of fear, anxiety, and potentially high levels of physical exertion during such activity could yield situations of cardiac risk for certain individuals, no previous research has described the physiological nature of high ropes course work. The purpose of this study was to observe the metabolic and cardiovascular responses to a typical high ropes course experience. METHODS: Seventeen subjects gave informed consent to complete a 5-element sequence on an indoor high ropes course. The elements included step-swings (SS), swinging tires (ST), a 4-inch balance beam (B1), a vertical cargo net (CN), and a second beam (B2). These elements were positioned in series at a height of 20 feet above the floor. Expired air was analyzed continuously using a portable open circuit metabolic analyzer and heart rate (HR) was recorded at 5-second intervals via telemetry. Pre- and postcourse blood samples were obtained via finger-prick and analyzed for lactate (BL). Systolic (SBP) and diastolic (DBP) blood pressures were taken at an orientation session prior to each subject's test date and at pre-, mid-, and post course points during each test session. RESULTS: The mean ropes course work time was 11.2 +/- 2.9 min. Mean averaged/peak oxygen uptake (VO2), ventilation (VE), HR, and energy expenditure (EE) were 13.9 +/- 2.3/21.6 +/- 3.7 ml.kg-1.min-1, 36.4 +/- 8.1/49.6 +/- 10.3 l.min-1, 142 +/- 16/167 +/- 15 b.min-1, and 5.1 +/- 0.9/7.7 +/- 1.0 kcal.min-1 respectively. In descending order, mean EE was 6.2 +/- 1.1, 6.2 +/- 0.8, 5.4 +/- 1.0, 4.5 +/- 0.5, and 4.2 +/- 0.5 kcal +/- min-1 for the B2, ST, CN, B1, and SS elements respectively. Blood lactate increased (p < 0.05) from a pre course value of 1.9 +/- 0.6 mmol.l-1 to 5.0 +/- 1.1 mmol.l-1 post course. SBP values at pre- (136.7 +/- 16.0), mid-(169.8 +/- 19.7), and postcourse (154.1 +/- 19.2) were higher (p < 0.05) than the orientation SBP of 126.2 +/- 14.7 mmHg. Mid- and post course SBP means were significantly higher than the precourse mean. A significant difference was found for DBP between the midcourse (86.3 +/- 8.9) vs the orientation mean (79.1 +/- 6.8) only. CONCLUSIONS: Based upon the results of this study, average high ropes course work can be classified as aerobically moderate to heavy, at just over 4 METs with peak periods over 7 METs. Transient elevation in DBP may occur during elements with a high level of upper body work. High ropes course work does not present an unusually high physiological stress for healthy, physically fit individuals.