Side Effects. Side effects are rare; still symptoms like ear irritation, acute inflammation of the ear canal and pinna are reported. In some cases the pet might experience lack of appetite, vomiting, diarrhea, or hearing loss during the course of treatment, which might require immediate medical aid.
Furthermore, if the median age of a marathon participant is about 40, then the average maximum heart rate of a U.S. marathoner is about 180. Seventy percent of 180 is 126, while 80 percent is 144. Therefore, the heart rate of a mid-pack runner during a marathon is near the middle of the range -- between 126 and 144, or 135 beats per minute.
Your resting heart rate should be between 60-100 beats per minute. If you are an athlete or train a lot, your resting heart rate could be lower. That is an average. Resting heart rate above 150 is tachycardia (fast).During exercise, you should shoot for between 40-60% of your heart rate max which is generally estimated by subtracting your age from 220. Example a 20 year old (220-20=200) would have a max heart rate of 200.You should be careful when starting exercise not to get your heart rate too close to max.For athletes-or people who often perform cardiovascular activity  - a normal resting heart rate may be closer to 40 beats a minute.      If your your heart rate is continuously above 120 bpm or below 40  bpm you should consult a doctor.