I am 59 and i working cutting trees for a campground for the summer. We are at 6000 ft. in the mountains. My heat rate at rest is 50 to 80. When i start work my rate is around 110 doing light work cutting. When i start picking up the log. the logs are 4ft long and very in weight 40 to 80 pounds. Most of the time i am going up and down hills. My rate will go up to 145 and sometimes as high as 169. but as soon as i put the log down my rate drops with in 3 to 5 mins to 110 again. Is this dangers to me. By the way my blood pressure is around 130 /80 my weight is 225.