Back in June I was running 60-70 miles weekly with mostly easy runs 7:10-8:00 and an occasional tempo (5:20 pace) and long run (11-20 miles). At this point I was in about 15:40-15:50 shape (5k obviously). FYI I had just turned 16 at this point. Throughout April-July I had not altered my training regimen (paces/volume) by much. During this training period my resting heart rate was getting lower indicating better fitness (50s) and my HR during easy runs (mostly 7:15/mile) was pretty good 130-150 (max HR of 206). Then comes the suspected COVID case. Around June 8th I had an itchy/sore throat+diarrhea for a few days which I didn’t think much of at the time. On June 10th I went for a run initially feeling fine (I was well hydrated etc.). By mile 2 I started feeling pretty fatigued and saw my HR (chest strap) was ~165 which was odd. Once I hit mile 3 I could barely run and had to slow to 12 minute miles to feel somewhat “easy”. I decided to cut the run short. The following few days the fatigue and high HR continued with values being 180-190+. I then decided to visit the doctor in which I received a full blood panel, everything was normal except for vitamin D. The doctor said to take off a few weeks and it was probably just the heat. I ended up taking two months off playing only golf and doing weightlifting. When on the driving range it felt like a steady state run in terms of effort and my HR was 150-160 just standing there accompanied by minor shortness of breath (exertional related). On september ~3rd I decided to do a 1 mile time trial and thought everything was fine by now. Ended up running a 6:05 mile (previous fitness was ~4:20). I highly doubted it was due to deconditioning considering the golf and weight trading and, my baseline fitness with no training is ~5:20. A few days later I ran a 10:00 mile and my HR reached 180 which was cause for concern. I returned to the doctor and we booked an appointment for a cardiologist+electrophysiologist. After the appointment I noticed standing up out of the car my HR increased from ~65-70 to 150. I checked my HR because I noticed the same feeling the morning before in which my legs were extremely heavy. After this I began documenting thoroughly my HR and BP during positional changes. I found that my HR would consistently increase ~50-100 bpm upon standing accompanied with harder breathing and, my BP would rise along with it to 190-230/100 before usually dropping back down after 20-120 seconds. As well upon laying down my HR drops 20-30 (often palpitative and upon standing again would go to 140. An interesting thing to note is that HR never went extremely low if laying in prone positition. At the electrophysiologist we did stress+pulmonary test, my stress test time was 19 minutes and they noted nothing out of the ordinary. As well, they said an ECHO was not required as one was done in may (for unrelated reasons which proved to be benign) Then I did a 10 day Holter moniter which revealed the exaggerated heart rates and periods of 2nd degree heart block (electro wasn’t concerned). After that I did more tests including cortisol etc. Nothing was out of the ordinary. The electro+doctor concluded it wasn’t the heart causing the rhythm but instead something elsewhere in the body. The Doctor noted the cause could be a virus and they reccomend a low dose of beta blockers so I could resume training for xc and track. I haven’t started taking the beta blockers yet but I’m just wondering, this be from COVID-19? My antibody test taken recently was negative however 40% are false negatives and, many lose the antibodies (at least the detectable dose) after a few months. It just kind of sucks how I went from a 4:20 miler to a 6:05 miler in the span of basically a few days.