Despite evidence that 'walking for pleasure' represents the most common leisure-time physical activity, the exercise intensity associated with 'walking for pleasure' in the obese has not been established. Heart rate (HR), perceived exertion (RPE) and walking speed were assessed for 30 obese and 20 non-obese adults as they completed two 2 km-walk tests on alternate days and were compared with a third 2 km walk with subjects walking 'as fast as possible'. Despite both obese (O) and non-obese (NO) groups rating the intensity of 'walking for pleasure' as 'light', HR and RPE data for only the NO group complied with definitions of 'light' intensity effort. 'Walking for pleasure' was characterised by a higher absolute (15 bpm, P < 0.05) and relative (70% of predicted maximum, P < 0.01) HR in the O group, which was representative of the transition between 'moderate' and 'hard' intensity exercise. The findings in the third, maximal trial were comparable across groups for all variables. Adiposity exerts a relative elevation-of-intensity effect on the cardiovascular system at walking speeds consistent with 'walking for pleasure'. 'Walking for pleasure' is sufficient to improve cardiovascular fitness in obese, but not normal-weight, individuals.