Effects of betablockers on physical performance

A forum for anything related to cardiovascular training.

Moderators: cassiegose, Boss Man

Post Reply
Posts: 8
Joined: Tue Feb 24, 2015 9:36 pm

Effects of betablockers on physical performance

Post by ittiandro »

I am 77, I train regularly and run outdoor 5 km three times a week and I go to the gym in winter.
Last week I had for the 1st time an episode of atrial fibrillation while at rest at home and the cardiologist at the E.R. put me on medication ( Metaprolol, betablocker), while suggesting to continue training as usual. As known, this betablocker inhibits the production of adrenaline, which, think, is not a serious problem, since usually, when I run, I don't have hungry dinosaurs behind me....

Already one week after going on beta blocker medication( Metaprolol) , I noticed a difference in body response when running on the same track, for the same work out duration, but I don't know what t make out of it. .
1. As expected, h.r. has decreased by about 10-15 bpm : it still keeps at +/- 60 bpm at complete rest, but it has difficulty to rise over 115 bpm under effort, whereas before I could easily increase it to 130-135, sometimes even 140 bpm.

2. There is an uphill stretch, where heart used to rise at the beginning of training to around 140 bpm.Kind of hard, for a few minutes, but with training, it came down to 130-135 and considerably less effort. .

One week after taking the beta blocker, h.r, when running, has decreased to about 118 bpm on the very same stretch but, unlike before, it seems to have reached a ceiling, because it doesn’t go over 118-120 bpm, even though it feels even less hard on the heart..

Does this mean that the betablocker has put a ceiling to the maximum rate heart can deploy , therefore preventing me from improving cardiovascular conditioning as I continue to exercise ?
Or does the betablocker work synergically with the cardiovascular effort, thus allowing me to improve conditioning. ( within the limits of age, of course) as the heart gains efficiency through exercise?

3.The calories expenditure, by cardio watch, has also decreased, when practicing on the same spot and for the same duration.
In addition, the ratio between calories from sugar and calories from fat shown by the cardio watch has changed: now, out of a total of, for inst, 600 cal, the % of calories from fat has increased to about 45% , whereas before it used to be 35% or less.

This sounds like the heart now works less, everything being equal, because usually when I look at the cardio watch summary, the more intensely I have worked out, the higher is the number of calories drawn from the blood sugar. Typically, the ratio would be 70/30 or even 80/20 for a more intense training.. I’ll speak to cardiologist, but if somebody has experience with physical exercise and betablpckers, I'd like tp have comments

Post Reply