I ran past someone smoking and inhaled a lot of smoke does this put me at greater risk of lung cancer?

No: A single exposure to second hand smoke will not alter your risk for lung or any other cancer. Keep up the exercise. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.