Training & Nutrition - Higher Heart Rate

Sorry if this seems like a really dumb question and the answer is simply "Ride more," which it probably is since its the answer to 90% of bike problems. :crash:

I went for my first rides in about a week and a half yesterday night and today and my heart rate was parked in the high 170s / low 180s for much of it with a final average of 172 bpm. I've been sick for the past couple of weeks [living in a college dorm exposes you to all sorts of diseases. :twitchy:] but I rode during one of those bouts and even then, my heart rate was pretty close to my usual average of around 150.

Is it possible for fitness to dissolve that dramatically in 10 days? I felt much worse than I typically feel when riding throughout much of the day.

Granted, I'm on a new bike since then but this bike is lighter, stiffer, and should fit me better since its the correct size. Its also a big morale booster and placebo effect alone should've kept me going [or I've been deceived by the people from the Road forum. O noes!]

I realize heart rate isn't the best think to compare due to natural variation from temperature and such but a 20 bpm jump over the same 30 mile course on a day with such moderate weather just seems strange.

Probably just my overactive 18 year old mind though.

the thing we have to remember is that HR is an 'indicator' of the body's function, not a direct measurement of body activity. We're measuring the 'pumping' activity responsible for blood and O2 transport (among other things) and not the actual aerobic activity of the system. As an indicator, its a pretty good one when in reference to an individual's condition (not meaning conditioning...).
Both an elevated HR or inability to reach higher HR can be indicative of systemic issues.
If the body is working more to overcome infections or other immune system issues, or needs to do extensive repairs or rebuilds, then a relatively elevated HR would be expected for any activity.
Another 'indicator', using HR, of this state would be an elevated 'resting' HR. If that is happening also, then most likely the body's metabolism is working much harder in areas outside of muscle activity - some constriction in the 'delivery' system could also be causing this.
If you have questions regarding a High reading for a level of activity, then get a resting HR reading (in some fashion which you have standardized taking the resting HR). If that's elevated, then you can pretty much figure that some 'condition' is causing the high readings.
I've also found that there are times when I lack the inability to get the HR up to the higher levels I'm capable of, normally. I suspect this is an indicator of muscle fatigue - not being able to process as much O2 as normal. On those days I'm not feeling anywhere near 'normal' and getting the heart rate even close to the higher levels is just not possible.
General 'conditioning' can change quickly, but that's measured in numbers of days, usually 2 or 3 weeks or so. Large fluctuations from one day to the next are usually down to some variation in the body.
Changes in equipment could also conceivably cause a large measureable change, but that would take some huge improvement or degradation.
10 days off, depending on how solid a 'base' you have, could have some affect. Buts its the point where lose of conditioning just starts to happen.
If you felt crappy on the day you experienced a high overall HR, then you were 'cooked' more than normal or possibly even sick.
I wouldn;t read too much into a day or 2 of elevated HR (barring some other symptoms of real illness).
If it persists, then look to what might be happening.
Have you set up your new bike to give the same 'position' as before? This is also assuming that your position on the old bike was well placed. Relatively Small changes in position for anyone riding a lot will have a real effect on body cycling function.
At 18 your body is still developing, and that could have an effect - and going thru some sort of change.
Add up a bunch of small factors and they might result in a large variance.
no real answers, but the more info you collect about yourself, the more you'll learn about how your body reacts and adapts.

You don't lose base fitness in a couple of weeks. You lose a bit of fine-tuning, but not base fitness.

What you did is you went out and rode hard when you were just getting recovered from being sick.

So, slow down for a few rides.

I think your interpretation of your HR while active, is backward.
Low HR while resting is an indication of fitness.
Low peak HR while riding, is an indication of fatigue.
I am able to hit my highest HR and turn my best times and speeds, after not riding for a couple days.

It is when doing back-to-back riding days, or toward the end of 6-12 hour rides, when my peak HR is lowest, and I feel like I'm dragging a ball & chain behind the bike.

Agree with Shima. It's the Freshness Effect. That's about the right length of time for it to be at a maximum. That's how you'd like to feel all the time: an "easy-revving heart." That's how I describe it to myself. Ready to race. You need a high HR to deliver the blood volume to carries the oxygen that your muscles need to develop max power at LT. So that's a good thing. The trick is to have a training program that gets you in shape, while still preserving that easy-revving heart. So that's why coaches say that most cyclists ride neither easy enough nor hard enough. You need to ride easy enough a lot of the time, so that when you do VO2Max intervals or attack on a hill, you can reach close to max HR, probably somewhere over 200 in your case.