Kinesiology Commons^™

Impaired Skeletal Muscle Blood Flow Control With Advancing Age In Humans: Attenuated Atp Release And Local Vasodilation During Erythrocyte Deoxygenation, Brett S. Kirby, Anne R. Crecelius, Wyatt F. Voyles, Frank A. Dinenno

Health and Sport Science Faculty Publications

Rationale: Skeletal muscle blood flow is coupled with the oxygenation state of hemoglobin in young adults, whereby the erythrocyte functions as an oxygen sensor and releases ATP during deoxygenation to evoke vasodilation. Whether this function is impaired in humans of advanced age is unknown.

Objective: To test the hypothesis that older adults demonstrate impaired muscle blood flow and lower intravascular ATP during conditions of erythrocyte deoxygenation.

Methods and Results: We showed impaired forearm blood flow responses during 2 conditions of erythrocyte deoxygenation (systemic hypoxia and graded handgrip exercise) with age, which was caused by reduced local vasodilation. In young adults, …

Chronic Exercise Modifies Age-Related Telomere Dynamics In A Tissue-Specific Fashion, Andrew T. Ludlow, Sarah Witkowski, Mallory R. Marshall, Jenny Wang, Laila C.J. Lima, Lisa M. Guth, Espen E. Spangenburg, Stephen M. Roth

Exercise and Sport Studies: Faculty Publications

We evaluated the impact of long-term exercise on telomere dynamics in wild-derived short telomere mice (CAST/Ei) over 1 year. We observed significant telomere shortening in liver and cardiac tissues in sedentary 1-year-old mice compared with young (8 weeks) baseline mice that were attenuated in exercised 1-year-old animals. In contrast, skeletal muscle exhibited significant telomere shortening in exercise mice compared with sedentary and young mice. Telomerase enzyme activity was increased in skeletal muscle of exercise compared with sedentary animals but was similar in cardiac and liver tissues. We observed significant age-related decreases in expression of telomere-related genes that were attenuated by …

Sensitivity Of The Wolf’S And Rostein’S Algorithms To Evaluate Local Dynamic Stability From Small Gait Data Sets, Fabien Cignetti, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

The Wolf’s (W-algorithm) and Rosenstein’s (R-algorithm) algorithms have been used to quantify local dynamic stability (largest Lyapunov exponent, λ ₁) in gait, with prevalence of the latter one that is considered more suitable for small data sets. However, such a claim has never been investigated. To address it, the λ ₁ of the Lorenz attractor was estimated using small data sets and varied delays and embedding dimensions. Overall, the λ ₁ estimates from the R-algorithm got closer to the theoretical exponent than those from the W-algorithm. The W-algorithm also overestimated λ _{1 …}