Perceived exertion and metabolic cost during progressive and randomized walking protocols

The objective of the study was to ascertain whether selected physiological responses and the perception of effort varied during four different walk protocols where speed increased progressively 3, 4, 5, 6, and 7 km.hr-1 (progressive treadmill walk (PTW); and progressive land walk (PLW); or where the participant adjusted to random changes of speed e.g. 6, 4, 7, 3, and 5 km.hr-1 during a randomized treadmill walk (RTW); and a randomized land walk (RLW). Mean stature and mass of the seven participants was 1.75m and 70kg respectively, with a mean body fat of 15%. Metabolic measures included heart rate, relative oxygen uptake, ventilation, respiration frequency, which increased in a linear fashion up to 6 km.hr-1, however at 7 km.hr-1 there was a significant increase in metabolic response notably during the PLW, and to a similar, although lesser extent in RLW, probably as a consequence of the loss of kinetic energy when turning at each cone in order to maintain the speed during each shuttle. Respiration frequency appeared to be a more sensitive indicator of physical exertion, exhibiting a rapid elevation at 6 km.hr-1. The perception of effort during each mode and at each speed was largely congruent during each walk protocol. Keywords: Walking, Ratings of Perceived Exertion, Metabolic, Progressive and Random