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, …

Muscle Contraction Duration And Fibre Recruitment Influence Blood Flow And Vo2 Independent Of Contractile Work During Steady-State Exercise In Humans, Jennifer C. Richards, Anne R. Crecelius, Brett S. Kirby, Dennis G. Larson, Frank A. Dinenno

Health and Sport Science Faculty Publications

We tested the hypothesis that, among conditions of matched contractile work, shorter contraction durations and greater muscle fibre recruitment result in augmented skeletal muscle blood flow and oxygen consumption (O2) during steady-state exercise in humans. To do so, we measured forearm blood flow (FBF; Doppler ultrasound) during 4 minutes of rhythmic handgrip exercise in 24 healthy young adults and calculated forearm O2 via blood samples obtained from a catheter placed in retrograde fashion into a deep vein draining the forearm muscle. In Protocol 1 (n = 11), subjects performed rhythmic isometric handgrip exercise at mild and moderate intensities under conditions …

Body Mass Bias In Exercise Physiology, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

In certain physically demanding occupations, especially the military, body mass bias has substantive implications. Work physiologists have determined that despite body mass bias in the common military physical fitness tests, the larger service members were often better performers of the physically demanding occupational tasks (Bilzon et al., 2002; Lyons et al., 2005; Rayson et al., 2000). That is, they could carry more, more easily evacuate casualties, and better engage in heavy materiel handling. Yet, the smaller personnel were achieving better scores on the physical fitness tests, the results of which have significant promotion and advancement implications (Vanderburgh & Mahar , …