Determining Exercise Intensities of Gardening Tasks as a Physical Activity Using Metabolic Equivalents in Older Adults

Abstract

The objective of this study was to determine the exercise intensities of 15 gardening tasks in older adults using a portable indirect calorimeter. Twenty older Korean adults (16 females, four males) older than 65 years of age (average 67.3 ± 2.7 years) were recruited from the community of Gwangjin-gu, Seoul, South Korea. The subjects visited a garden created for the study at Konkuk University, Seoul, South Korea, three times and performed a total 15 gardening tasks. Subjects wore a portable calorimetric monitoring system (Cosmed K4b2) with telemetry that allowed measurement of oxygen consumption as they conducted each gardening task over a 5-min period and during a subsequent 5-min rest period while seated on a chair between each task. Their heart rate was also continuously measured using radiotelemetry (Polar T 31) during the test. The gardening tasks performed were of low to moderate intensity physical activities [1.7–4.5 metabolic equivalents (METs)]. Tasks using both upper and lower body (e.g., digging, fertilizing, weeding, raking, tying plants to stakes) required moderate-intensity physical activity (3–4.5 METs); those using the upper body while standing or squatting (e.g., pruning, mixing soil, planting seedlings, sowing, watering using a watering can or hose, harvesting) were low-intensity physical activities (1.7–2.9 METs); and tasks requiring limited use of the upper body while standing (e.g., filling containers with soil, washing harvested produce) were the least demanding physical activities of the gardening tasks tested. The results will allow more precise tailoring of gardening activities of older individuals to achieve appropriate levels of activity for good health.