can someone explain what is going on here
On mondays I ride a fixed gear for 3 hours in zones 2/3 as part of my training plan. A couple weeks ago after a week of recovery I took off on my ride on an unusually warm day. I felt great and my PE was really low. It didnt feel like I could come across terrain that would challenge my legs. When I looked down at my hr it was almost in zone 5! I didnt feel like I was going hard at all and the rest of the ride I had to work to keep my hr down.
The following week after a harder ride on sunday I head back out for the same ride with temps back in the 30s. During this ride my PE is super high but my hr is barely in zone 2. Little changes in grade cause me to really labor to get the pedals around. For the entire ride I feel like I am killing myself to keep my hr from slipping back into zone 1. This is typically what this ride is like.
Today I again went out for the same ride. Its warmer today and I rode hard yesterday. Again PE is pretty high but my hr is in low zone 2. For the entire ride I had to focus to keep my hr from dropping too low but it wasnt as bad as last week.
On all these rides I take the same route so the only differing factors are the weather and what I did the day before. My gearing is low, 39x16, so its not like I can really go that hard anyway.
Im sure whats going on is pretty basic and easy to figure out but I dont know it.