This time, it might be 18 beats per 15 secs, which will be 72bps. After a week of doing this, you will get a mean average difference . When the difference is up - ie more than the average don t train that day. You are showing signs of stress and slight infection. You can, however, train more severely when the difference is down .
Infections severely deplete vitamin C stores in the eyes and adrenal glands.
Also, what vitamin C you consume is devoured quickly to help manufacture new white cells lymphocytes, which help fight infections. Raise your vitamin C intake to 1,000mg daily for a month. The mineral zinc has long been associated with immunity to infection. Runners are known to be liable to a deficiency because a lot is lost via sweat. Raise your zinc intake to 30mg daily.