When i jog or am in the middle of a 5k, my heart rate can go up as high as 160-170. for my weight and age, what should be the maximum heart rate i should allow while exercising. i am 59, 196 pounds, and do not feel any strain at this heart rate?

Maximum heart rate?: The calculation for maximum heart rate would be 220 minus age, so if we round your age up for the calculation (no offense meant), we'd have a maximum heart rate of 160. That being said, that's not to imply that something bad will happen if your heart rate hits 161 or even 170 for a short time. Remember, it's just a calculation and does not take into account your overall level of fitness.

Your maximum: Heart rate is typically 220-age in years. Yours would be 160 by this formula. Training can keep your heart rate higher than predicted if you are in good aerobic shape!