Energetic Cost and Preferred Speed of Walking in Obese vs. Normal Weight Women

Abstract

BROWNING, RAYMOND C. AND RODGER KRAM. Energetic cost and preferred speed of walking in obese vs. normal weight women. Obes Res. 2005;13:891-899. Objective: We tested the hypotheses that walking is more expensive for obese women, and they prefer slower walking speeds that minimize the gross energy cost per distance despite a greater relative aerobic effort [percent of maximal oxygen uptake (V O 2max )/kg]. Research Methods and Procedures: Twenty adult women, 10 obese (BMI ϭ 34.1 Ϯ 3.2 kg/m 2 ) and 10 normal weight (BMI ϭ 20.4 Ϯ 2.1 kg/m 2 ) volunteered. To determine the metabolic rate and energy cost per distance vs. speed relationships, we measured V O 2 and V CO 2 while subjects walked on a treadmill at six speeds (0.50, 0.75, 1.0, 1.25, 1.5, and 1.75 m/s; 5-minute trials, with a 5-minute rest period between trials). We measured preferred walking speed on a 50-m section of level sidewalk and V O 2max using a modified Balke treadmill protocol. Results: Walking was 11% more expensive for the obese subjects, but they preferred to walk at similar speeds as normal weight subjects (1.40 vs. 1.47 m/s, p ϭ 0.07). Both groups preferred walking speeds at which their gross energy cost per distance was almost minimized. Obese subjects had a smaller V O 2max /kg, so they required a greater relative aerobic effort at the preferred speed (51% vs. 36%, p ϭ 0.001). Discussion: Obese women preferred a walking speed that minimized energy cost per distance, even though this strategy required a greater relative aerobic effort than walking more slowly. Our results suggest that walking slower for a set distance may be an appropriate exercise recommendation for a weight management prescription in obese adults.

Demand response to improved walking infrastructure: A study into the economics of walking and health behaviour change

“…We have applied the model to walking in East Belfast, 8 Northern Ireland, UK, and find that our empirical data supports our theoretical model: 9 minutes walked are negatively affected by the value of time and by a person's wealth. We 10 further find that people living in more walkable areas and in areas which have a good 11 availability of local shops and facilities within walking distance, tend to report walking more 12 than other people. 13 Considering the monetary value of walking, a public programme that would enhance to a result, it appears that people walk more in more walkable areas because they live in those 10 areas, and not because they walk more in general.…”

“…5 Several studies have confirmed that walking reduces the development of cardiovascular Many factors influence or facilitate the choice to walk for either travel or recreational 10 purposes, including the availability of footpaths, the attractiveness of the route (e.g. 11 interesting facades, a variety of architecture, the absence of long, blank walls), route choices 12 for variety and safety, the number of destinations within a walkable distance (e.g. work 13 places or nearby shops), and the opportunity cost of walking.…”

“…Wang et al (2005) 8 compared direct medical costs between active and inactive people to assess costs and 9 benefits of building and maintaining new bike/pedestrian trails, finding a benefit cost ratio 10 of 2.94. Sustrans (2006), in a cost-benefit analysis of three walking and cycling routes, found 11 benefit cost ratios ranging between 14.9 and 32.5. actually walk 10km/day for commuting purposes. 22 Other studies have used the hedonic price method, focussing on "walkability" -the quality prices in more walkable neighbourhoods are about US$4,000 -US$34,000 higher than 3 houses located in areas with average levels of walkability.…”

“…Walking is not a 9 popular transportation mode, unless for very short journeys, and is often only considered in 10 conjunction with a second transportation mode -walking and driving, walking and travelling 11 by bus, or walking and travelling by train -as walking alone is impracticable for longer 12 journeys (Litman, 2003). 13 The economic value of outdoor recreation sites, including walking facilities has been 14 extensively studied, first using a revealed preference method, the travel cost method, 11 In this paper we are interested in valuing the demand for walking in the neighbourhood, 12 with neighbourhood walking defined as walking in the area of a city where a person also 13 lives. Walking in a neighbourhood is a good not traded in any market.…”

“…6 In the fourth specification, Table 2, Model 4, we add variables for respondents' income, car 7 ownership and minutes of walking in a different area to a respondent's neighbourhood, 8 calculated as the total amount of walking minus the amount of walking in a respondent's 9 neighbourhood, which aims to capture the effect of substitute opportunities for walking. 10 Similarly, the variable 'car', captures both a measure of wealth, as well as a substitution 11 possibility for walking as a mode of transport. A log-likelihood ratio test shows that model 4 12 outperforms model 3 at the 5% level (Chi-squared is equal to 11.32, with 4 degrees of 13 freedom).…”