Exercise tactic change

I'm looking at all the exercise I've done so far as a warmup.

I gave blood on Thursday so I didn't do pushups on Friday, and ended up not doing any exercise. Friday I was reading an article I found on "patientslikeme" that talked about good symptom relief after vigorous exercise (80-90rpm on a bicycle). This morning I tried pushing very hard for one mile of biking. I did a 2:20 km pace rather than the 3:45 I had been doing. It was hard and I had to slow down a couple of times. I'm going to try adding to the distance daily. I tried to increase the pace on my walk too, but only managed a 12 minute / km pace - about the same as I've been doing.

I want to get to the point where I can notice the symptom relief mentioned in this article.