The science supporting the health benefits of a physically active lifestyle across the life span is strong. Of all types of physical activity behaviors, ambulatory activity (most obviously walking, but also any lower limb locomotion) is probably the single most important to measure and promote. Walking for exercise is consistently the most frequently reported leisure-time physical activity. In addition, walking is the foremost form of human-powered personal transportation, a part of many nonautomated chores, and a functional aspect of almost all types of personal mobility.
The Walking Behavior Laboratory has established itself as a world leader in the objective monitoring of walking behaviors using accelerometers and pedometers to capture steps per day. For example, we have recently led the writing of three international consensus articles focused on how many steps per day are enough? in children/adolescents, adults, and older adults/special populations. With the growing awareness of the detrimental effects of an overly sedentary lifestyle, we are expanding our research to also answer how many steps per day are too few? in relation to several important health outcomes.
Steps per day is a measurement representing physical activity volume, and it has been criticized for lacking a description of intensity of movement. Physical activity guidelines worldwide include an element of intensity in their recommendations. In the past year, we have begun to focus on the assessment and analysis of patterns of minute-by-minute cadence (steps per minute), alone and together with steps per day, as a means of getting at intensity. Cadence increases with speed of walking and intensity, and so the study of cadence under free-living conditions represents a simple pattern-recognition strategy. Puttering can be discriminated from walking, and running can be identified with reasonable ease in data sets based on objectively monitored physical activity. In this next year, we will be investigating the relationship between time spent at different cadence levels and important health outcomes, including body composition, diabetes, and overall cardiometabolic health.
To achieve the labs mission, we employ a broad range of quantitative and qualitative methods, tap into existing data sets, and seek funding to support original research studies. We have adopted measurement technologies including an electronic walkway that allows us to instantaneously capture research participants gait speed, stride lengths, and cadence. We are conducting studies to elucidate the relationship between different cadences and energy expenditure in adults, older adults, and children in order to better estimate energy expenditure of walking in free-living conditions. We have recently received an American Heart Association award to support our WALKMORE study of the relative impacts of two pedometer-based walking interventions (one focused on accumulating more steps per day and the other on steps per day + cadence) in overweight/obese, postmenopausal women with elevated blood pressure. WALKMORE will inform public health messages related to improving blood pressure in a population at increased risk of cardiovascular disease.
Research in this laboratory is supported by grants from the American Heart Association, the U.S. Department of Agriculture, and the National Institutes of Health.