EFFECT OF ADDED WEIGHT ON HEART RATE AND VO2 DURING UPHILL BICYCLING OVERGROUND VERSUS ON A TREADMILL.

Abstract

325 The current study examined the physiological responses to bicycling uphill: 1) overground (OG) or on a treadmill (TM); and 2) with or without a 4.0 Kg weight. Eight subjects (Mean±SD Age = 28 ± 6.8 yr; Mass = 82.7±12.3 Kg; Stature = 1.74±.06m) rode uphill at 10 km · hr-1 for two min at 3% grade and seven min at 5% grade. Each subject rode on a 2.5 X 1.1m treadmill and an asphalt paved road with and without(randomized block order) a 4 Kg weight attached to the bicycle's seat tube. Heart rate (HR) was obtained via telemetry using a Polar XL HR monitor. VO2 was measured via an Aerosport TEEM 100 metabolic analyzer. Mean data from minutes 3 to 8 were analyzed via a paired T-test. A significant difference was found in VO2 between OG = 2.91±.45 and TM 2.49±.37 (p<.05). In addition, during OG there was a significant difference between weighted = 3.00±.50 L · min-1 vs. unweighted = 2.82±.41 L · min-1 (p<.05). However there was no difference during TM weighted = 2.51±.37 L · min-1 vs. unweighted = 2.45±.32 L · min-1 (p>.05). There was a significant difference of HR for OG 158.0±8.4 bpm vs. TM = 144.9±5.13 bpm (p<.05). However, there were no differences in HR for the OG (weighted = 159.3±8.9 bpm vs. unweighted = 156.8±8.3 bpm) or TM conditions (weighted = 145.5±6.8 bpm vs. unweighted 148.1±7.7 bpm) (p>.05). Results of the current study indicate that VO2 and heart rate are different during uphill treadmill or overground bicycling. The difference is most obvious with the addition of weight during overground riding. These results suggest that the use of treadmill bicycling to describe overground bicycling may not be valid.