Lactate Threshold Test

mattgardiner

Hi all,

I'm after some opinions on lactate threshold results.

1st Test
Date: 28/1/2012
Time: 30mins
Average Watts for duration: 284 (~310 for first 10 mins, -270 for last 20mins)
Average Cadence for duration: 85
Average Heart Rate for last 20 mins: 170

2nd Test
Date: 14/3/2012
Time: 30mins
Average Watts for duration: 287 (290 for first 10mins, 284 for last 20 mins)
Average Cadence for duration: 85
Average Heart Rate for last 20 mins: 175

So the increase in power isn't particularly concerning for me. I've had a rubbish time and haven't trained more than a couple of times a week average so I'm pretty happy with staying the same. The big questions for me is over the 5 beats per minute jump in LTHR. If anything I remember feeling closer to passing out after the first test than I did yesterday. The one possible difference is in going off too hard in the first test but I wouldn't have thought that would make a difference to Heart Rate over second 20 mins - both tests were done fully committed.

Opinions appreciated.

pbt150

Heart rate is notoriously variable for a set effort, depending on what you've eaten/drunk, temperature, hydration, caffeine consumption etc. It's probably not worth worrying about.

Pokerface

I recently did a LT test. This was done in the lab where bloods were checked every 3 mins. My power curve was basically the same as the previous time I did (6 months prior) but my average HR was 20 beats per minute up. Across the whole curve. I actually ended up with a much higher Max HR than I previously seen.

The testers were left scratching their heads as to why this happened - but it won't affect my training.

So changes in HR do happen in these tests.

DRCorsa

Heart rate monitors are helpful but most times there are some factors affecting the numbers.
As Joe Friel has written, heart rate monitor tells one thing for sure, that you are alive.

mattgardiner

So is the result that it's better to base training zones on power than HR?

DRCorsa

mattgardiner wrote:

So is the result that it's better to base training zones on power than HR?

Absolutely!!!

amaferanga

If you have a power meter then you can forget about HR.

Pokerface

The only thing HR *may tell you (when comparing it to your power numbers) is your fatigue level. For this reason my coach insists that I wear my HR strap even though all my training is based on power.

DRCorsa

Pokerface wrote:

The only thing HR *may tell you (when comparing it to your power numbers) is your fatigue level. For this reason my coach insists that I wear my HR strap even though all my training is based on power.

You can "read" fatigue level by using the HR monitor only in conjunction with the powermeter, ie cardiac drift.

napoleond

DRCorsa wrote:

Pokerface wrote:

The only thing HR *may tell you (when comparing it to your power numbers) is your fatigue level. For this reason my coach insists that I wear my HR strap even though all my training is based on power.

You can "read" fatigue level by using the HR monitor only in conjunction with the powermeter, ie cardiac drift.

That's what he just said...

Alex_Simmons/RST

DRCorsa wrote:

Pokerface wrote:

The only thing HR *may tell you (when comparing it to your power numbers) is your fatigue level. For this reason my coach insists that I wear my HR strap even though all my training is based on power.

You can "read" fatigue level by using the HR monitor only in conjunction with the powermeter, ie cardiac drift.

I would dispute that. HR v power relationship may be a result of many factors, of which fatigue is but one. Attempting to parse out fatigue from such a relationship is not reliable, certainly not as reliable as other more direct indicators, such as how one actually feels and how much power they can produce.

mattgardiner

RIght, this is making a lot more sense. I had been working zones on HR before now and wondered why power for a particular zone looked great on some days and dreadful on others.

Thanks chaps.