Abstract
Background: Walking uphill and downhill on motor-driven treadmills has been included in different exercise programs for athletes or for rehabilitation purposes. The body’s response to uphill, level, and downhill walking is different, and those responses vary from one group of individuals to another. Abundant work has been done by considering the treadmill, but very few studies have been done by changing the gradient levels in these treadmills.

Aim and Objective: The aim of the study was to evaluate pulmonary responses, Stride Length, and perceived exertion during Uphill, Level, and Downhill walking in various Body weights among young adults in undergraduate students. The objectives were – (i) To evaluate pulmonary responses, stride length, and perceived exertion while Uphill walking; (ii) To evaluate pulmonary responses, stride length, and perceived exertion while level walking; (iii) To evaluate pulmonary responses, stride length, and perceived exertion while Downhill walking; (iv) To compare the pulmonary responses, stride length, and level of exertion experienced when walking uphill, level, and downhill.

Materials and Methods: After receiving approval for the study from the institutional human ethics committee, a sample of 60 people were enrolled who were subsequently divided into three groups based on their body mass index (BMI). Each group has 20 participants: the overweight group has a BMI of 25–29 kg/m2, the normal group has a BMI of 18.5–24.9 kg/m2, and the underweight group has a BMI of <18.5 kg/m2. Before being involved in the study, Informed consent was obtained after participants received a brief explanation of the study. 3 days in the laboratory were scheduled for the participants. Initially, the participant’s personal history and medical history were recorded. The anthropometric measurements were taken as per the recommended guidelines. On the 1st day, participants walked on a treadmill at level ground (0% gradient); on the second and 3rd days, they walked uphill (15% gradient) and downhill (15% gradient), respectively. For each session, tidal volume, minute breathing, and rate of perceived exertion, were measured.

Results: Findings within the intergroup revealed a substantial increase in the rate of perceived effort during uphill walking among the overweight groups compared to the normal and underweight groups. None of the BMI groups experienced any appreciable changes in tidal volume or minute ventilation (MV). When the intra-group comparison was made, it was discovered that uphill walking significantly changed the tidal volume, MV, and rate of perceived exertion when compared to level and downhill walking in all the BMI categories.

Conclusion: These findings provide a complete picture of the pulmonary changes carried on by the uphill, level, and downhill walking that we all perform daily as well as the variations in lung response at various body mass indices during exercise. These conclusions can therefore be used to recommend exercises for various BMI categories.

Key words: Pulmonary Responses; Perceived Exertion; Stride Length; Uphill; Level; Downhill; Treadmill; Exercise; Body Mass Index