Unless you've been working out in Australia over the past four or five years (g'day, mates), you probably haven't Heard of one of the fastest-growing fitness franchises Down Under, F45 Training. (Don't worry, I had never heard of it either.) Luckily for all of us, F45 Training has a studio within 20 minutes of my suburban Dallas home (and another soon to come literally down the street from my development). I was able to attend one of its strength circuits, called Panthers, and emerged after an efficient, challenging workout with a greater understanding of this Australian sensation.