
Originally Posted by
TrailRunAZ
Agree with lovbyts. If you're training cardio, and have any intensity at all, you'll be improving your cardio base. Your resting heart rate will go down, and it will be harder to get it up to the same levels as before without increasing the difficulty. If you're in good shape, hydrated, etc., your blood pressure will also fall along with your heart rate as your cardio improves (depending upon the effects of the "sups" you're on.
The time to start being concerned about a low heart rate is when you start having a noticeable arrhythmia (skipped beats, extra hard beats, flutters, etc.) because the rate is so low, you get light-headed when you stand up or exert, or you drop below 40-50, depending upon your fitness level.
I used to run 2-3 hours/day on trails, and my resting heart rate in the a.m., before getting out of bed, was as low as 39 sometimes. It usually ran around 50-55 during the day. Some of it was genetic, the rest was due to the cardio fitness. But I had a shitload of pvc's (extra heart beats) due to the low rate.
Check your resting heart rate in the morning, before getting out of bed. See what that tells you about your fitness level. If you're low due to cardio, you can try more exertion on the cardio equipment, but it's hard when you're used to a certain level, eh. High intensity intervals on the stair stepper should also tell you how the heart rate responds. That jacks my rate quickly even when I'm fit as hell.
The only real thing that would prevent your rate from increasing would be something like taking a beta blocker (blood pressure medicine), aside from the esoteric cardiac conditions.
Any other probs, or just the rate? If you're trying to burn fat, the lower rate won't hurt you anyway, and it will keep some glycogen in your muscles instead of burning it all.