I started commuting to work on nice days last week. (40 mile round trip) On the ride into work (about 1 hour), I pushed myself fairly hard, keeping my heart rate at about 90% max. 12 hours later, time to head home. I could feel the lactic acid sitting in my legs, but figured I'd tough it out and head home staying around 80% max. I was heading into the wind on the way home and felt like I was working harder, but my HR would not go above about 75%, no matter what I would do.

Can someone explain what was going on with my physiology?

Matt

Heart rate ......... there's never ending knowledge and things to learn about our body.

Keeping your heart rate at about 90% max is tough, how long did you hang in there? Lactic acid buildup is near definite when you push yourself so much. Have you been exercising regularly before commuting to work?

I think it's just a temporary overtraining syndrome? What I do know is that when you overtrain, you have a tough time reaching a target heart rate. I think it's just your body not allowing you to take yourself too far, thus you are unable to reach above 75% of max HR. It could also be that you're not fit enough since after 12 hours, the lactic acid is still there. It should have sort of cleared after so long. You should include some stretching anyway, it'll definitely clear up most of the lactic acid. Take it easy anyway Matt, there's no point reaching such a high heart rate. It's only a commute right? I know guys do have the competitive spirit in them, but try to control it, do only such tough commute once in a while.

hm... with 12 hours time in between that's a tough one.

i would think you taxed BOTH your muscles and your cardio system and you just weren't recovered fully in 12 hours (up to 2 days for full recovery)...

although normally i would expect more muscle fatigue and reduced performance and an ELEVATED HR, so not exactly sure -- normally the inability to get your HR up is from lack of water/nutrients/energy... i assume you ate and drank a fair amount while at work, like at lunch for example?

but i think it sounds normal enough if you really pushed yourself that hard and harder than normal.

I was very well hydrated and ate a sensible lunch. I usually train between 65-85%, closer to the 85. This was certianly more work than my normal workout. It sounds reasonable that I probably didn't allow myself enough time for a full recovery?

Yeah, what's the deal? You aren't actually a "training machine" You just can't go all out and get to MHR?

The "heartrate" statistic of a given person is part of a "cardio "vascular" "" feedback loop.

Remember the "vascular" part? That's the part of the "loop" that carries oxygen, energy and the "feedback" signals to the heart to work harder and faster.

Depending on the status of your muscles and energy supplies in you blood, you may not have enough "feedback" for the heart to work any harder.

If you want to see how hard you can make your heart work, you have to rest between efforts.....