Hi I'm at week 6 of the C25K programme - although it has taken me since Feb to get here never having been fit in my life and I'm 45! I did the first 2 runs of week 6 last week without any problem and then donated blood. Took 48 hours off strenous exercise as recommended and then tried run2 of week 6 again. For the first time I failed to complete a run. Has anyone any advice on how long it will be before I am back to where I was pre blood donation. I've never noticed much effect from donating before - been doing it for years- but then I've never done any exercise beyond walking since school! Any advice very welcome - in the meantime I am planning to stick with R1W6 until it gets a bit easier.