I go hiking with my sister pretty much every week (we bubble together - we don't see any one else). She isn't as fast as me, but generally I don't mind because I prefer her company over getting a stronger cardio workout. But every now and then I wonder just how much workout I'm sacrificing. She always says she is sore the next day, and I never feel anything. Well, this weekend she wasn't able to go, so I decided to go for speed. A trail that usually takes us three and half hours only took me 2:25! Wow. And dang, am I sore the next day! I may have to go on more hikes without her (in addition to the hikes with her).