Today has become a 'rest day'. It had to happen as I found the run to circuits yesterday rather hard going and I was generally lacking in energy. I suspect that the cause is basically 2 long swims; Sunday and Tuesday, both longer than I've ever swum before. These followed on from a reasonably long run on Saturday so altogether I'm feeling the strain.
My morning heart rate has become elevated at a fairly consistent 47bpm which is a 15% increase. I've just measured by HRV and at a resting of 51bpm it was 40 which is rather low too. These parameters both support the idea that I'm tired!
It seems to be impossible to do 3x runs, 3x swim, 1x cross training and at least 1x rest day per week.