Pohl (2003) The physiological responses to running and walking in water at different dephts

Introduction to Aquatic Exercise

Aquatic exercise, recognized for its therapeutic benefits, offers an alternative training mode that mitigates impact forces, potentially reducing injury risk. This study delves into the physiological responses of walking and running on underwater treadmills at different water depths, comparing them with land-based treadmill exercise. Understanding these responses could refine aquatic exercise applications in therapy and training.

Methodological Approach

Six recreationally active subjects participated in this study, undergoing six tests encompassing walking and running across three conditions: land, thigh-deep water, and waist-deep water. The primary focus was on measuring oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), stride frequency (SF), and oxygen cost per stride. These metrics provided insights into the physiological demands of aquatic exercise compared to traditional land-based exercise.

Findings and Analysis

The study revealed that both walking and running in water, irrespective of depth, increased VO2 and HR compared to land-based exercises. Notably, thigh-deep water exercises elicited the highest VO2 and HR, indicating a greater physiological cost. However, running in waist-deep water didn’t augment VO2 and HR to the same level as thigh-deep running, suggesting buoyancy at this depth may reduce the physiological cost of movement. The stride frequency remained consistent across depths during walking but decreased in waist-deep water during running, highlighting the impact of water resistance and buoyancy on movement dynamics.

Implications for Training and Therapy

Aquatic exercises, particularly in thigh-deep water, impose higher physiological demands than land-based exercises, making them beneficial for cardiovascular training and rehabilitation. The buoyancy in waist-deep water appears to moderate these demands during running, offering a gradient of intensity that can be tailored to individual needs, especially in therapeutic contexts where minimizing joint stress is crucial.

Conclusion: Enhancing Exercise through Water

This study underscores the effectiveness of aquatic exercise in augmenting physiological responses, offering a valuable alternative to land-based training. The variance in physiological demands at different water depths provides a versatile framework for designing exercise programs tailored to specific fitness or rehabilitation goals. As such, incorporating aquatic exercise can significantly contribute to the diversity and efficacy of training and therapeutic regimens.

Keywords: Aquatic exercise, Running in water, Walking in water, Physiological responses, Underwater treadmills, Buoyancy, Oxygen uptake, Heart rate.