Thanks fiona that info supports my experience so far. i have continued to exercise and found it’s kept me sane . My exercise levels which were initially low due to treatment increased slowly over the past 14 months . I saw a cardiologist and had a stress echo the other day as I wanted to ramp up what I was doing. The cardiologist was right up to date on BC And exercise and was really supportive of my efforts to maintain fitness. One of his colleagues is studying this area. Anyway the great news is that the echo revealed I’ve got a young persons heart, I’m 62, the reason being all my years of exercising mostly cycling. So take that BC !