As people age, everyday tasks become more fatiguing. Current research does not yet show how physical activity affects the ability to withstand fatigue. The purpose of this research is to quantify and compare muscle fatigue in response to prolonged walking in younger and older males and females. The older adults are categorized as being active, healthy, or impaired. 

The hypothesis is that there are differences expected between men and women, as well as the younger and older groups, and  these differences will be mitigated by physical activity levels. Differences in sex may be related to variance in muscle strength. 

Older adults completed maximum knee extensor testing before and after a 30-minute treadmill walk at their preferred walking pace. Maximum knee testing was performed using dynamometry at 0 degrees per second (dps), 120 dps, and 240 dps. The 30 minute treadmill walk included 1 minute challenge periods with 3% incline increases at minute 7, 14, and 21. Outcome measures included changes in torque and power (ratio of the post- and pre-walk measurements) and will be expressed as a percentage of baseline. 

Significant differences across the groups could explain higher risk for falls and musculoskeletal diseases. The literature shows that aging is associated with redistribution of muscle mechanics, and that physical activity can help mitigate aging effects. Reducing levels of muscle fatigue during everyday tasks for older adults promotes better health outcomes as well as a higher level of independence, which improves quality of living.