As I'm aging, I feel out of shape. Just doing all my own yard work, I can tell I'm slowing. My doctor asked me, how much do you walk. That took me by surprise. That was as good as her, how much fiber do you eat question.
Hiking up mountains can be more difficult, depends how old you are. Hiking implies a more strenuous walk to me. Usually, it's on flat land for me. I avoid overdoing it. Sure would like to loose 10 lbs. I tend to think if my heart rate was challenged my T would go up too. I hope your T goes down, and your walks are long.