the GNU version of the Collaborative International Dictionary of English
v. To exert too much.
The Century Dictionary and Cyclopedia
To exert or exercise too much; exert (oneself) to excess: usually reflexive.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
v. exert (oneself) excessively and go beyond one's strength
Word Usage
"Fifty-nine percent overexert, meaning that they sometimes will try and keep up with their kids, try and do activities that they probably have no business doing."