Sprint last for approximately 20 seconds. Running all settings MAX out including AA (I used SMAA, not sure which AA to use for my GTX 670 though) at 1920X1080. (Except for Shadows which was enabled to the lowest settings.)

Without FRAPS:
Min: 33
Avg: 40
Max: 50

With FRAPS:
not worth mentioning

Accessories used:
Razer DeathAdder (Mouse) 3500dpi
Razer Goliathus (Mousepad) Speed Edition
Microsoft Sidewiner X4 (Keyboard)

System Specs:
Z77 Gigabyte G1 Sniper 3 E-ATX Motherboard w/ Creative Sound Core Recon3Di
Core i7 3770K running @ stock 3.5 Ghz
Gigabyte Windforce Nvidia Geforce GTX 670 OC Edition
OCZ Vertex 4 128GB SSD
3TB Seagate Barracuda 7200 rpm HDD
Corsair Vengeance 1600 Mhz 4X4GB Memory
Corsair H100 Hydro Cpu Cooler

Very nice. Love the breathing effects.