Energy expenditure during walking and jogging.

Area of Science:

• Exercise Physiology
• Biomechanics
• Sports Science

Background:

• Understanding the physiological demands of different exercise intensities is crucial for exercise prescription.
• Treadmill-based exercise allows for controlled assessment of walking and jogging responses.

Purpose of the Study:

• To compare physiological and subjective responses during treadmill walking versus jogging at equivalent speeds in physically active young women.
• To determine if higher speeds of walking elicit greater metabolic and cardiovascular stress than jogging.

Main Methods:

• Fifteen healthy, active women (mean age 26.9 years) underwent maximal oxygen uptake testing.
• Participants completed treadmill protocols involving walking and jogging at speeds ranging from 4.0 to 10.4 km/hr.
• Physiological measures included oxygen consumption, heart rate, plasma lactate, and respiratory exchange ratio; subjective exertion was also recorded.

Main Results:

• Oxygen consumption, energy expenditure per distance, and heart rates were significantly higher during walking compared to jogging at speeds ≥8.8 km/hr.
• Plasma lactate and respiratory exchange ratio were significantly higher during walking versus jogging at speeds ≥8.0 km/hr.
• Subjective ratings of exertion were significantly greater during walking than jogging across overlapping speeds.

Conclusions:

• Walking at speeds ≥8.0 km/hr resulted in energy expenditure equal to or greater than jogging at the same speeds.
• Higher energy expenditure during high-speed walking was associated with elevated heart rate, respiratory exchange ratio, and lactate levels.
• These findings suggest that brisk walking can be a metabolically demanding alternative to jogging.