To say this basically, during a workout, your muscles use Calcium to initiate contraction (it actually binds to the Troponin Complex in a mysoin head on a muscle fibre (thick filament) and causes the troponin complex and tropomyosin to shift which exposes binding sites on the thin filament enabling the head to bind and initiate a crossbridge ready for contraction). Therefore, it is likely that you have exhausted your supply of calcium during the workout and the heads cannot bind correctly. So just take calcium suppliments in the morning or before your workout.
If this does not work then it will most likely be a potassium deficiency which will cause your neurones to have a different ion resting potential slightly changing the nerves potential difference and causing them to misfire. To my knowledge there is not much you can do about this.