The Buffalo Protocol says to reduce aerobic exercise to a heart rate that does not cause headaches. Then, after 2 weeks, try increasing the heart rate by 5 to 10 bpm. If this rate can be sustained without headaches for 2 weeks, another increase can be tried. Some need to spend more than 2 weeks at the safe heart rate before increasing heart rate. The vascular structure in the brain needs to regain control over blood flow/shunting that is lost during the injury. For some, this can take quite some time.

The current goal is retraining the brain, not maintaining or improving cardio ability. That can be restored in due time. Pushing heart rate into symptom levels can have a negative impact on recovery.