Why fatigued & dizzy

[87LtdT]

57 years old, 5'11", 240 lbs, diabetic (but no longer on meds because A1C dripped into 5's w/60 lb weight loss), was on cholesteral meds but they stopped too w/same weight drop but Dr has left me on 40mg of Lisinopril for high BP...on meds it's around 120/80.

Have ridden bike 1000 miles this summer, 15-20 per ride at 14-16 MPH, for exercise and to prepare to participate in a 41 mile group ride conducted yesterday.  Just easily rode 41 miles 3 weeks ago in preparation.  During yesterday's ride I began getting abnormally tired at 15-20 miles...became dizzy twice as slowed for a break on side of road.  Fatigue grew, breathing labored, muscle tightness across shoulders/neck...none of this experienced at all during this summer.  At 31 miles I quit....rested about 15 minutes, rode 5 very slow miles when a fellow rider returned to pick me up.  Today I feel fine except for a little tiredness which seems normal.  Drank plenty of water, had 2 bananas in morning and a sandwich before the 1PM ride time.

Any idea why I folded like this??

Thanks, Bob Kolhouse

[87LtdT]

This is kinda like going to family doctor.  You know...you don't really get any information other than a return appointment.   At least I didn't have to pay at the window.

[87LtdT]

No response???