Heart rate
A good indication of your fitness level is measuring your resting heart rate. For most people, that should be 60-100 beats per minute. Elite athletes will have a lower resting rate. A resting heart rate higher than 100 means your body is working harder to do its job and has been associated with high blood pressure and heart disease.
You can take your own heart rate by placing your index and third fingers gently against your neck and counting your pulse for 15 seconds, then multiply that number by four.