Hard run today@practice.after we did air squats.even 20 reps would shoot my hr to 170,felt very lightheaded.2 1/2hr later, hr still not below85.im17.

Stop: If you are feeling lightheaded then you need to stop. If this is happening with an activity that you do all the time and normally don't get lightheaded with then you should see your doctor for some tests.

Tachy: Could be from fatigue and dehydration. Drink plenty of replacement fluids and rest. Resting tachycardia is a sign of overtraining and the likely culprit. Tell your coach about is so they can adjust your program a bit.