<qa>  What is the name of the test that will be performed at the University Hospital AintreePatients scheduled to undergo surgery or angioplasty of the iliofemoral segment for intermittent claudication will be screened for inclusion. Consenting patients will undergo ABI measurements and CPET before treatment and four weeks after treatment. Study measures will be performed in the respiratory physiology laboratory at University Hospital Aintree. Demographic and medical details will be recorded including gender, age, smoking history and pack years, medical history and treatment and BMI. A record will be made of patuients latest full blood count which will be routinely available in all participants before the procedure. Ankle-brachial index will be recorded. The subjects will undergo full CPET. This includes recording of baseline spirometry, full ECG monitoring throughout the test, measurement of ventilator parameters and recording of Borg breathlessness and leg fatigue score every minute. At the end of the test the reason for cessation will be documented. The test will be incremental with a 10-20W ramp determined according to baseline MVV aiming for the subject to exercise for 10-12 minutes. The test will involve 3 minutes rest, 2 minutes free-pedal followed by continuous ramping until volition. Recording will continue for 5 minutes recovery 