By Mark Clevenger
October 20th 2016
PR’s (personal records) are the reason most people train and compete. To do something you’ve never done before is one of the most exhilarating feelings we can experience. Unfortunately as we get older we learn that sometimes these PR’s come at a price. It’s like binge drinking. When you’re 21 you can go out drinking all night, get 4 hours sleep, get up and go about your business no problem. When you’re 31 it takes 2 full days to get rid of the hangover and you burn at least 1 PTO day trying to recoup. The gym PR’s are no different, their hangover can sometimes put you on the couch for the next two days.
Why is it that hitting a big PR takes so much out of us? Doing something you’ve never done before requires your body doing something it’s never physically done before. Our bodies are terribly inefficient at things it doesn’t know how to do, requiring our nervous system to work in hyper drive to accomplish the given task. Our nervous system is highly metabolic and is subject to fatigue like all other metabolically active tissues in our bodies. This hangover (overly tired, insatiable hunger, total body soreness) is the physical display of neural fatigue.
When our nervous system attempts to activate muscles to complete a movement at a weight it’s never done before it doesn’t know how many times it needs to discharge a signal to the muscles involved, how frequent those signals should be, or the correct sequence of motor unit activation. This causes it to go into hyper drive and is the cause of neural fatigue. Once the nervous system figures out the recruitment patterns and how much activity it needs to achieve sufficient force for that particular movement at that particular weight, then that lift (and weight) starts to feel easier to accomplish. Your nervous system now knows it doesn’t need to throw the kitchen sink at the muscles to complete the lift.
So the next time you go on the weight room equivalent of binge drinking and do something crazy like set a 300# PR on a tire flip (cough, cough), you’ll understand why you feel like the walking dead the next day. At that point burn a PTO gym day, get some rest, eat some good food, and get ready to make a hero’s return to the gym because everyone was talking about your awesome lift while you were gone.
- MacIntosh B.R. Gardiner P.F. McComas A.J. Skeletal Muscle: Form and Function. Second edition. Champaign, IL: Human Kinetics; 2005.