Friday Afternoon Poster Presentations: Posters displayed from 1:00–6:00 p.m.: One-hour author presentation times are staggered from 2:00–3:00 p.m., 3:00–4:00 p.m., and 4:00–5:00 p.m.: F-30 Free Communication/Poster - Exercise Equipment and Monitoring Systems: FRIDAY, JUNE 2, 2006 2:00 PM – 5:00 PM: ROOM: Hall B
New exercise equipment aimed at faster weight loss, with reduced impact forces, is constantly being marketed to the public. Traditional weight bearing, treadmill exercise continues to serve as the physiological standard of comparison for these new devices especially with regard to energy costs.
PURPOSE: To examine the physiological effects of Treadclimber (TC), a new “weight independent” exercise device, as compared to treadmill (TM) and elliptical trainer (ET), at a given level of perceived exertion (RPE=6, using Borg 1–10 scale). RPE was selected as the constant since as a practical matter, it is frequently used to judge exercise intensity.
METHODS: Thirteen (males=7, females=6) college-aged (20.1+2.1 yr) volunteers performed a maximal graded exercise treadmill (GXT) running test to assess aerobic power. Following this, three 10-minute sub maximal steady state exercise bouts were performed on seperate occasions using the three modes of aerobic exercise in a manner that elicited the desired “hard” RPE intensity. During each sub maximal bout, oxygen consumption (VO2) and heart rate (HR) were measured continuously while systolic blood pressure (SBP) was taken at the midway point and at the end of the exercise. RPE was taken every two minutes to ensure a constant level. ANOVA (alpha level=.05) was used for statistical analysis.
RESULTS: Subjects were above average in maximal aerobic power (males=48.7±12.7, females=45.1±3.9 ml O2/kg/min) while being average in body composition (BMI: males=22.5±1 .8, females=24.9±2.7 kg/m2). To achieve the desired RPE intensity, subjects exercised at 6.7±1.0 mph 0% grade (TM), 100 watts at 63.7±14.4 rpm (ET), and 3.5±0.4 mph resistance of 8 (TC). Significant VO2 differences existed between the conditions with the highest being TM and the least for TC exercise (38.2±3.9 vs 31.7±5.1 vs 28.6±3.9 ml O2/kg/min; TM vs ET vs TC, respectively). HR results were significantly different between the conditions, being similar to VO2 results (174.8±9.8, 171.5±12.1, 148.4±14.4 bpm for TM, ET, and TC) while systolic BP (mmHg) was significantly higher for TC (149.1±15.9) compared to TM(135.1±4.4) and ET(132.7±2.4).
CONCLUSIONS: When using perceived exertion as the marker for relative exercise intensity, TC consumed 25% less oxygen and thus fewer kcal than TM, perhaps due to reduced weight bearing similar to that of ET. While SBP was significantly higher during TC, the cardiovascular stress as indicated by double product was about the same as the other two modes of exercise because of a significantly lower HR. Compared to TC and ET, treadmill exercise is better in terms of energy expenditure rate with less of an increase in blood pressure than TC.