o·ver·stretch 
(ō′vər-strĕch)
(ō′vər-strĕch)v. o·ver·stretched, o·ver·stretch·ing, o·ver·stretch·es
v.tr.
1. To extend or use beyond what is reasonable, usual or proper: The army is overstretched in its deployments.
2. To subject to undue strain: employees who are overstretched working overtime.
3. To stretch (one's muscles or another body part) to the point of strain or injury.
v.intr.
To stretch one's body or muscles to the point of strain or injury.