https://philmaffetone.com/180-formula/
I will throw this out there, hopefully someone else will will find it useful.
Came across this website a while back and it was a big help. Walking up hills typically had me winded and needing to take a breather. Slowing down while walking was not easy at first, but it paid off in the long run. Also some great keto diet plans.
Never used a monitor (besides on a treadmill), but tried to keep breathing in check. Basically Learned to slow my pace at the start of a hill. Most of the day hikes have been in the 7-10 mile range and sometimes include some steep slopes and/or off trail hiking.
MAF And