Sprinting will get adrenaline pumping, but in a Fight or Flight situation it's a LOT of adrenaline all at once. G enerally it's very difficult to simulate this.
Physical exertion WILL NOT cause the effects of stress-unless you are stressed by physical exertion. You may get trembling from muscle fatigue,you will get rapid heart rate but it will not induce-tunnel vision, auditory exclusion, tachypsychia, etc. In order to train under stress you have to be stressed.