Contrary to the 5D Mark II who is stuck at a 30 fps, 7D owners have a nice array of frame rate to pick from according to their needs. The optimal shutter speed is in direct relationship with the selected frame rate. Consult the chart to select the best shutter speed according to the desired frame rate.

• 24p: 1/50
• 30p: 1/60
• 50p: 1/100
• 60p: 1/125

If you need to learn more about the reasoning behind this, visit the explanation on canon5dtips.