Exercise has varying effects on blood pressure depending on the type of workout. Blood pressure readings absolutely can effected by exercise, but for how long is a little tougher to answer. Let me explain. During exercise, your heart pumps more blood out to your body per minute, while the blood vessels within the muscles you are using expand. These two countering effects cause a rise in your blood pressure. If you are working one muscle group (i.e. biceps curls), the your blood pressure rises a lot during the exercise. If you are working a large group of muscles (i.e. jogging), then your blood pressure will go up a little. Within an hour of completing exercise you blood pressure should be close to normal. Therefore it is unlikely that your blood pressure was significantly effected by the exercise that day. However, there is no way to know until you get your blood pressure checked on a day you don't exercise. Keep in mind that as people get older, their blood pressure tends to rise. So it is possible that you have high blood pressure
that needs treated. The only way to tell is have it taken 1 or 2 more times. I would say you should return to the doctor
soon and have it re-checked. Good luck.