I bought the belt for my husband who has been an avid runner for decades.  He has never felt comfortable, safe running with a dog.  He also felt that trying to deal with a dog compromised his workouts. In December, we adopted a Dobie. (Over the years we have adopted four adults- we always have one at a time and raise them as companion dogs.)  This girl is a beauty and is built more like a Greyhound than a Doberman! She is natural runner! Reno has had a ton of snow and ice, so last weekend was the first time my husband Buddy could run.  He and Molly the Dobie finally had a chance to try the Cardio Canine.  They both loved it!  Frankly, I am amazed.  What a great find.  PS Buddy carries his walkman in the water bottle pouch. Another great feature!