From: harry@cv.hp.com (Harry Phinney)
Subject: Re: Fitness thoughts
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
X-Newsreader: Tin 1.1 PL4
Date: Tue, 1 Sep 1992 03:01:56 GMT

pae@blackcat.stortek.com (Phil Earnhardt) writes:
: This thread started with questions about unfit people getting fit. In that
: context, it is indeed *far better* for exercisers to mostly stay well below
: the anerobic threshold (i.e. the onset of blood lactase accumulation).

Agreed.  I think that people often make this more complicated than
necessary.  If someone goes out and exercises (walk, run, cycle, roller
blade, etc) at a constant pace for 20 or 30 minutes they are virtually
guaranteed to be working within their aerobic range.  A well trained
athlete can push slightly above AT for that time span, but it is
extremely hard work.

: 1. Since the aerobic metabolic paths require the energy released by burning
:    carbs at several steps, it certainly seems plausable that the aerobic
:    pathways would get shut down when the muscle cell is going at an anerobic
:    level of intensity.

I don't see any evidence of this, although Ed apparently believes that the
fat metabolism may indeed be hindered above AT.  

: 2. Untrained atheletes have a far lower tolerance for anerobic exercise --
:    the blood lactate concentration will kick up at far lower exercise
:    intensity than it will for trained atheletes.

This all depends on how one defines "exercise intensity".  The AT will
occur at about the same perceived effort level regardless of fitness.
The fitter individual will simply be putting out more power at that
level of discomfort/pain.  Again, if one maintains a steady pace for
more than 20 minutes or so they are not going to be above AT.  The less
fit and thus less experienced individual will have a harder time
selecting a pace that they will be able to maintain for the duration of
the workout.  I would expect this problem to remedy itself in the first
few workouts.

: 3. The accumulation of lactic acid in the muscle cells, without proper
:    warm-down, will hinder recovery, possibly limiting the number of workouts
:    that one can do in a week.

Again, I agree that the person interested in general fitness and/or
weight loss should exercise below the AT, and I agree that exercising
above the AT can indeed limit the total amount of work one can do over a
given time.  Like Ed, I am unconvinced of the role of lactic acid in
determining the recovery time, but I do certainly agree that intense
workouts will require significantly more rest.

: >On the contrary, one's maximal oxygen use
: >(and thus the maximum output level of the aerobic metabolisms) will
: >occur at an exercise intensity beyond AT (i.e.  VO2max). ...
: 
: Harry, have you seen any studies that have looked at VO2max in non-athletes
: (specifically, unfit people)?  Does this property hold for them as well?

Much of the training for endurance athletes focuses on trying to raise
their AT to be as close as possible to their VO2max point.  In general,
an unfit person will experience AT further from VO2max than will a well
trained individual.

: What is the relationship of the fat mechanism's peak output and the anerobic
: threshold?

This is a good question, and one to which I do not know the answer.  I
strongly suspect that it is dependent on training and fitness level.
Perhaps the references which Ed mentioned could shed some light on this.

: Another "stress and pain" may arise from those people trying to understand
: the subtle nuances of human physiology. For unfit people starting an exercise
: program, it's unnecessary to read the McArdle text,...

Very true!  This newsgroup tends to be a mix of misc.weight-loss,
rec.body-building, and rec.sport-with-no-other-group.  Each group of
people (if not each individual) definitely brings their own perspectives
and needs.

Harry Phinney   harry@hp-pcd.cv.hp.com