Slackline! Great form of Play

As I have been reading I have noticed that alot of people have the same issue as I do. Low intensity cardio is boring! I like to walk as much as the next person but sometimes it just gets boring and I want something to change it up!
Well as you know the primal blueprint says to Play and to do the low intensity cardio, lift heavy things, andddd do some high intensity every once in a while too.
I think i found the perfect thing to combine all of those and it's pretty primal in itself. I mean Grok could have built one of these things if he wanted to!
What I found is called Slacklining and it's done on a SLACKLINE. Basically it's a tie down strap/ratchet strap whatever you want to call them, run between two trees or poles level to the ground. Between 1 and 2 feet off the ground is good. You use the ratchet to get all the slack out and make it really tight, then you can walk on it, stand on it, balance on it, do pushups on it, or if you get really daring like some of my friends do flips off of it. Just don't break your neck though please!
Caution: After doing this for a couple hours, you will have sore muscles on muscles you didn't know you had.
Warning: May significantly increase your ability to surf, ski, snowboard, balance, skateboard, and pass sobriety tests.
Sooo has anyone ever done this or am I the only one?
"It is your responsibility to control the outcome"
"In our society, people respect weight loss. Even if you do nothing cool or interesting or memorable for the rest of your life, you'll have done that."
"Is a brief moment on the lips, worth a long time on the hips?"