Thanks for providing more information.
Low oxygen levels can result in dizziness.
However most common reason of dizziness after exercise may include low blood pressure, slightly dehydrated due to sweating, low blood sugar, vasovagal pre-syncope.
So your blood sugar levels, Serum electrolytes, blood pressure monitoring should be done.
If your symptoms 'll persist then you should get an EKG and have your orthostatic blood pressure checked before you do any more strenuous exercise.
You may need tilt table testing as well.
Otherwise hydrate yourself with plenty of fluids, energy drinks like Gatorade.
Eat frequent small meals throughout the day.
Take proper rest for a while.
If your symptoms 'll not improve over the time then consult your doctor or visit ER ASAP.
I hope this helps.
If you have any further query then feel free to ask.
Positive feedback and bonus are highly appreciated.