DesnaePhoto

There are many discussions about how to determine your lactic acid threshold outside on the road. Wrong time of year here for that. How do you determine LAT indoors? I have a set of rollers and spin bike at the gym. Please, no running!

I've discovered my sustained HR has increased. i used to be able to ride for a long period at 165. Now I can keep it at 172-174 and not suffer an explosion.

So, suggestions on how to determine LAT indoors?

Thanks

Creakyknees

well, using HR it's basically the same idea - the effort / HR that you can hold for 20 min's.

be sure to use a powerful fan because heat will significantly skew your HR.

trigger

The sticky at the top of the forum about LTHR seems to be applicable to an indoor trainer / rollers. At least, that's how I set mine. However, my heart rate indoors seems a good 10 points or more lower than comparable (PE) efforts outdoors. If this is the case, that'll affect LTHR, no?

I mean the number I got seems accurate for indoor use, but when I think of the outdoor numbers that I was seeing all season it seems way low. When I say accurate I mean I went as hard as I could for the test, and subsequent training does seem to implicate that number (or thereabouts) as my LTHR.

EDIT: My fans indoors are not the best. In what way(s) does heat affect HR?

Carbonfiberboy 

My HR is also about 10 beats lower inside than out for the same effort. This is due to "arousal," as they say. Next time you're on the rollers, relive your last competitive ride, when you attacked near the top of the hill, or some such, but don't change speed. Watch that HR spike! I try to get around that indoors by doing a 5 mile test on my resistance-equiped rollers. In that short test, one simply rides absolutely as hard as one can sustain, mostly over LT (though HR may not show it), and takes the average. So that's a pretty rough guess, but it does attempt to get around the arousal problem. Going as hard as one can seems to get the hormones flowing. YMMV.

But in the end, yes, I think one should run a lower HR indoors to get the same training effect that one is looking to get from a HR that is perhaps biased toward outdoor riding. Or run the same HR, but for a shorter length of time. Personally, I'll ride rollers at the outdoor HR, but for about 75% of the time I would spend outdoors on the same training plan. That cuts the boredom a bit.

Heat increases HR or reduces the ability to put out watts (whichever way you want to think about it) because your body is busy trying to get rid of the heat and the energy spent on that can't make it to the pedals. I'm noticeably faster indoors with a 24" box fan right in front of my face. They say you should have a serious enough fan that you need to wear your outdoor riding glasses. That's how you tell.

trigger

Huh. I have a trainer only, so resistance isn't the problem. I'll work on a better fan system as the one I have at the moment sucks ... I'm interested to see what sort of a difference it makes. I sure do get hot right now.

Shayne

Just to add to the airflow while riding indoors talk:

I just got power on my bike a couple weeks ago. I've been doing 20 min. intervals on the trainer with a 20" fan right in front of my face. I've been trying to hold 300 watts, which is sub threshold, probably 90%-95%. Been coming in with an avg. in the high 290's. Basicly trying to raise my FTP through SST this winter.

The other day, I took my bike and trainer to a team trainer session. There were no fans and after an hour my power was way down, WAY down. I could hardly get to 200w. The thing is my HR was up in the 90-95% zone and my PE was high. If it were not for the power readings, I'd have no idea that something was amiss.

What I need to figure out is, was this workout a wast of time because the watts were low or did I still benifit since my HR was in zone? Anyone have an idea on that?

Carbonfiberboy 

Good for you! IMHO, no workout is a complete waste of time, however some workouts are more effective than others. In the case of your hot workout, at least your heart got some work, which is good. However your muscles, mitochondria, and energy delivery systems didn't get the workout you intended for them. OTOH, you got some hot weather training, unfortunately probably contraindicated at this time of year.

Shayne

That's pretty much what I figured. Sundays ride download had an avg. temp of 38, so not really looking for hot weather training. Next time I'm bringing my own fan. Also, need to clue in the rest of the team so they're not missing out. thanks