The Impact of High Intensity Exercise Upon EPC Number and Function in Young Women

The purpose of the study is to examine the effects of different exercise intensity training programs upon blood vessel function and circulating blood cells involved in blood vessel repair in young women. The long term effects of exercise may be beneficial to cardiovascular health and it is important to understand the training methods that are the most beneficial. In particular we aim to determine if brief maximal exercise improves the function and stiffness of blood vessels and enhance blood vessel repair. Two methods of exercising are being compared, exercise bouts involving intermittent exercise and exercise completed all at once, but at a very high intensity.

High intensity exercise training, Vascular health, Endothelial function, Circulating angiogenic cells, endothelial progenitor cells, Aerobic capacity, Arterial stiffness, Traditional and emerging cardiovascular disease risk factors

Interval exercise involving repeated Wingate tests (30s durations of maximal exercise on a cycle ergometer).

Continuous exercise of maximal exertion that has been work matched to an initial bout of interval exercise of 4 x 30s of maximal exercise. This exercise is performed on a cycle ergometer.

3 session per week of exercise on a exercise cycle ergometer. Each session involves 30s of maximal exercise followed by 4.5 min of easy cycling at 10W. This is repeated 4 times at each exercise session.

3 sessions per week of an exercise intervention involving maximal cycling until the participant has completed an amount of work equivalent to a sprint interval training session. This exercise lasts between 3 and 3.5 minutes.

A measure of aerobic capacity determined during an incremental exercise test to volitional fatigue on an exercise ergometer.

measures of in vitro cell migratory ability, adhesion and classification of endothelial progenitor cells

The stiffness of the carotid artery is measured using a combination of ultrasound imaging and non-invasive blood pressure measurements. Lower degrees of stiffness are more favourable.

These cells are involved in vascular repair and proliferation and may be measured using flow cytometric methods. Specifically cells with CD34 and CD309 antigens are enumerated.

Inclusion Criteria: Young healthy females Between 18-25 years old No on medication (this includes contraceptives) Exclusion Criteria: Medication use (including oral contraceptives) Amenorrhoea High blood pressure Very active (>3 hours per week of organized physical activity)