Metabolic costs and rating of perceived exertion during backward walking in water and on dry land.

The purpose of this study was to compare metabolic costs, rating of perceived exertion (RPE), and stride frequency during backward walking in water and on land. The walking speeds in water were set to be half of those on land. There was no significant difference in metabolic costs and RPE between backward walking in water with a current and on land, at slow and moderate speeds (P > 0.05). However, at the fast speed (i.e., 3.0 and 6.0 km · h(-1) for water and land, respectively), the metabolic costs and RPE during backward walking on land were significantly higher than when walking backward in water with a current (P < 0.05). With regard to backward walking at faster speeds, if the walking speed in water with a current is set at half the speed on land, then the speed will be inadequate for inducing metabolic costs and RPE that are similar to those produced on land.