Hi,i am a 25 year old female with a bmi of 30. i have recently begun exercising after being somewhat sedentary for a few months. the previous 2 times i did high intensity cardio, after 35mins i became very dizzy, saw "stars", felt nausea, light-headed, an

Exercise tolerance: Your body needs to gradually work up toward doing a longer or higher intensity exercise routine. Start by doing no more than "moderate" intensity, for no more than 20 minutes on the first day. Then, GRADUALLY increase it every 2-3 days, by 5 minutes each time, until you reach your ultimate goal. You pushed yourself too hard and too fast, and THAT is why you felt sick afterward.

Dizzy: You may need an EKG and to ease into an exercise program with your weight loss plan. Virtual consult if you need more definitive help

You need a check up: You need to consult your doctor and needs a complete physical exam and blood test and EKG. You may be Anemic,or have another medical condition causing the dizziness after the cardio . Meanwhile limit your physical exercises to less than what you are doing now.Are you eating properly or on any specific diet for weight loss

Water/slowly: When you haven't been exercising for a while you may need to start slowly and build up gradually. Also make sure you are eating regularly and drinking plenty of water before and after exercise. If symptoms persist see your doctor for an exam and blood tests.