I've only just began my journey with the Piggyback Rider. This allows me to go for long walks without worrying about my toddler getting tired. This is perfect to carry my 3 year old who is 32 lbs. He loves riding on it. But to test this unit out we went for a 4 mile walk around a park that is exactly 4 miles around. I must say that it's not the greatest for the 4 mile walk because after about 3 miles things start hurting. (Even the straps [assuming you're walking in a t-shirt and your child is 30+ lbs. like in my situation] anyway as comfy as the straps seem and even though the material is high quality and breathable, it starts ripping into your skin on your shoulders.) and that cute little monkey on your back now feels like a gorilla! So now I've limited it to about 2.5 miles walking near my house. I can see this will be great to trips to our local amusement parks (Knott's, Disneyland, Magic Mountain) and great for walks on the beach. I've used it twice and already have gotten a lot of stares and compliments as well from strangers.
Now for the hidden (conditioning) I'm so amazed at my energy level. I play intense 5 on 5 basketball with guys in their 20's and I can't believe how light on my feet I was laterally and even jumping after using The Piggyback Rider. (I'm no Kobe but I scored 13 pts the last game). So this conditions you in many other ways indirectly.