to put under very great strain; overwork
to exert great effort
verbo·ver·strained, o·ver·strain·ing, o·ver·strains
To subject to excessive strain, especially to force beyond a natural or proper limit: overstraining the environment.
To put forth too much physical effort.
(third-person singular simple present overstrains, present participle overstraining, simple past and past participle overstrained)