From the CCAA Research Junction
CCAA Grad students headed to "La Belle Province"!
This month the grad students at the CCAA are off to the Canadian Society for Exercise Physiology (CSEP) Annual Conference in Québec City, Québec October 19-22 2011. Check out some of the exciting work being presented!
PhD candidate, Matt Spencer is one of four students across Canada in the finals for the conference’s Graduate Student Award Competition!
Participation in exercise, activities of daily living, or work activities requires an increase in energy production. For activities lasting more than a few minutes, the energy demand is supplied principally by the aerobic energy system. However, at the onset of any activity, time is required to increase the rate of aerobic energy production. A main focus of research conducted at the CCAA cardiorespiratory laboratory is the study of oxygen uptake kinetics.
Here is a summary of Matt’s study:
At exercise onset, the adjustment of oxygen utilization (VO2 kinetics) to meet the new energy demand is not immediate; whether VO2 kinetics is limited by insufficient O2 delivery to the muscle or sluggish activation of factors governing O2 utilization within the muscle has been debated. Whereas impairing O2 delivery generally slows VO2 kinetics, independently enhancing O2 delivery or utilization has failed to resolve this issue. It is known that heavy-intensity “priming” exercise speeds VO2 kinetics, but simultaneously enhances O2 delivery and, potentially O2 utilization. We attempted to ‘nullify’ the increased blood flow associated with “priming” by having subjects breathe a hypoxic gas mixture (i.e., reducing O2 content); yet, the “priming” still potentially enhanced O2 utilization. Since no speeding of VO2 kinetics was observed when O2 utilization factors were isolated, it appears that VO2 kinetics can be limited by O2 availability. Identifying the key limitation of VO2 kinetics improves understanding of basic physiological control mechanisms.
Matt Spencer, PhD Candidate (Supervisor: Don Paterson, PhD)
Regulation of VO2 kinetics by O2 delivery: insights from acute hypoxia and heavy-intensity priming exercise in young men.
M.D. Spencer, T.M. Grey, J.M. Murias, J.M. Kowalchuk, D.H. Paterson
Brad Harwood, PhD Candidate (Supervisor: Charles Rice, PhD)
Fatigue-associated reduction in motor unit discharge rates (MUDRs) of the anconeus at maximal velocity in response to a submaximal dynamic fatiguing protocol.
B. Harwood, I.H. Choi, C.L. Rice
Matti Allen, PhD Candidate (Supervisor: Charles Rice, PhD)
Effects of knee angle on velocity-dependent power production of the triceps surae in young men.
M.D. Allen, B.H. Dalton, G.A. Power, C.L. Rice
Geoff Power, PhD Candidate (Supervisor: Charles Rice, PhD)
Preferential loss of velocity-dependent power at high loads following muscle damage.
G.A. Power, B.H. Dalton, W.J. Booth, C.L. Rice, A.A. Vandervoort
Don Paterson, CCAA Research Director
Which is more important for cardiometabolic health in older and middle-aged Canadian adults: moderate to vigorous physical activity or aerobic fitness?
S. Dogra, H. Tamim, D.H. Paterson
Submitted by Rob Little, CCAA Research Assistant.
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