Re: Heart Rates and Lactate Threshhold

On Jun 30, 7:23 pm, Michael Press <rub...@xxxxxxxxxxx> wrote:
In article
<1183208289.121060.71...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"joseph.santanie...@xxxxxxxxx"



<joseph.santanie...@xxxxxxxxx> wrote:
On Jun 30, 1:24 pm, rechungREMOVET...@xxxxxxxxx wrote:
On Jun 30, 12:18 pm, Justin Lewis <sendmesomemores...@xxxxxxx> wrote:

I am aware of the concept of LT or AT. Some claim it can be found
using the Conconni protocol. Others use lactate measurements.

Out of these sorts of tests one receives advice - this is the heart
rate you can maintain for about 1 hour (it can be expressed in terms
of wattage, I believe). The test was accurate for me: I had as an
average heartbeat the LT heartbeat for 72 minutes.

Question: if one is riding longer events (50 miles, 100 miles etc),
what heartbeat can be maintained for periods of 2 hours or 3 or 4
hours? Are they expressed as percantages of the LT heartbeat?

Justin! How ya doing? What kind of bike are you riding?

Anyway, the heart rate you observe is a response to physiological
demands for cardiac output. Overall cardiac output = HR X stroke
volume, so you can see that HR is only a part of the equation.
Nonetheless, the sustainable HR over a 2 or 4 hour period will be
close to the LT HR, subject to HR drift.

Given that HR is a response variable, it's not the ideal way to pace
effort.

HR drift in my experience is not significant for exercise in the 4
hour range. In my own case, drift is not noticable before 10-11 hours.

As far as what is maintainable for longer periods, I think fuel is
more of a limiting factor than lactate build up. In other words, how
much fat is being burned at this LT level, and can the supply (and
replenishment) of carbohydrate make up the difference.

Provided one has efficient enough fat metabolism, and enough available
carbs (glycogen, assimilatable food, whatever) there is no reason one
should not be able to maintain LT for 4 hours or more. LT by my
definition is the highest attainable output where blood lactate levels
remain stable.

Blood lactate level is a response variable also.
It lags cellular H+.
<URL:http://ajpregu.physiology.org/cgi/content/full/287/3/R502>

--
Michael Press

Indeed. In an effort to keep the hydrogen ion count down I have
experimented with "unnecessary" upper body movement to try to
metabolize some of the excess lactate when trying to maintain effort
levels above LT. The results have been needless to say inconclusive.
But for some unknown reason my fastest TT's have happened when
listening to music and dancing with my upper body. My playlist is
classified information.

Joseph

.

Relevant Pages

  • Re: Heart Rates and Lactate Threshhold
    ... Others use lactate measurements. ... average heartbeat the LT heartbeat for 72 minutes. ... demands for cardiac output. ... HR drift in my experience is not significant for exercise in the 4 ...
    (rec.bicycles.racing)
  • Re: Heart Rates and Lactate Threshhold
    ... Others use lactate measurements. ... average heartbeat the LT heartbeat for 72 minutes. ... HR drift in my experience is not significant for exercise in the 4 ... definition is the highest attainable output where blood lactate levels ...
    (rec.bicycles.racing)
  • Re: Heart Rates and Lactate Threshhold
    ... average heartbeat the LT heartbeat for 72 minutes. ... demands for cardiac output. ... carbs (glycogen, assimilatable food, whatever) there is no reason one ... definition is the highest attainable output where blood lactate levels ...
    (rec.bicycles.racing)