Aerobic power (VOzma) and cardiac output decrease in both sexes with age. Endurance exercise is known to affect cardiac structures and function, and could therefore attenuate the effects of ageing. However, recent studies have suggested that men and women of similar ages adapt differently to exercise training, including adaptations in cardiac function. In younger men and women, training modality is also an important determinant of improvements in cardiac function, but the full effects of exercise training need to be determined both centrally and peripherally. Cardiac power output (CPO) incorporates measurements of both blood flow (Q) and mean blood pressure (MAP), and is the most comprehensive .method of measuring overall cardiac function. In preliminary studies we elucidated the reliability and reproducibility of the C02 rebreathing technique used to determine Q, and the potential effects of caffeine ingestion on CPO. Then older men and women participated in 30 weeks of training, with step-wise increments in exercise intensity. This programme increased aerobic p~wer and increased the extraction of oxygen in the peripheries, but with no discernable effects on the heart's maximum pumping or reserve capacities. Six week endurance training (interval and continuous) of young men produced similar results. However using proteomics, interval training induced greater expressions of some contractile proteins, creatine kinase-M and heat shock protein 70 kDa, in the vastus lateralis muscle, suggesting possible conversion towards a faster muscle phenotype, but only in men. We conclude that endurance training with exercise intensities < 75 % HRR induces increases in VOZmax and peripheral adaptations in older people, but intensities >75 % HRR are needed to induce changes in cardiac function. We also found no discemable cardiovascular sex-specific differences in either young or older people after either interval or continuous exercise training. However, skeletal muscle exhibited contractile and metabolic adaptations to these training regimes, and these were sex-specific.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:485737 |
| Date | January 2008 |
| Creators | Holloway, Kathryn |
| Publisher | Liverpool John Moores University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://researchonline.ljmu.ac.uk/5891/ |
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