The last 3 days I did a little experiment. I pushed the sled 3 days in a row. And, I seemed to get in better shape each day believe it or not. Yes, I had to be VERY careful but the sled allows me to be very deliberate and high intensity without worrying about tweaking something. Pushing the sled is like doing sprints...but I am basically walking! I didn't expect to adapt as fast cardio wise. My recovery time was reduced each day. I obviously cannot keep this up, but this again points to the ability to do short bursts of higher frequency to get the body to make some gains. I am trying an experiment in the bench press for the next month. Keep in mind that my mind is pretty open about workout routines as anyone who has seen my KTA program can attest to this. KTA is really a shocker program based on the Blacksmith theory as I call it. Old time Blacksmiths didn't have the option of resting a day in between sessions. They were right back at it. And, they adapted. I do believe the hands and forearms are somewhat unique though. After all, we use our hands and forearm muscles constantly during the time we are awake. Even in the shower, shaving, and brushing your teeth...you use your hands.
The "rebound effect" is something that can be manipulated but it can be very much hit or miss unless you have a very well thought out and disciplined program. Train too much into overtraining territory and you might get injured or be too far into the hole to recover and rebound. There are also a lot of other variables that can put a monkey wrench into this tricky tactic for gains. So, I am experimenting with short and radical routines a bit and using myself as the lab rat. :)
I forgot to mention I even added weight to the sled in the course of the 3 back to back days. My body obviously got the message it needed to adapt and adapt NOW. I don't expect it to continue and won't be stupid and continue to pull sled again tomorrow or the next day.