Hello Tom,
My name is Linda Van Ceylon, I live in Fort Collins, CO and I've been an 
endurance rider for 18 years. (I've also had horses on the track but that 
is not my concern currently).  I'm pleased to meet you via the internet.  
Your opinions are much welcomed and valued! 
I've read some of your articles/books in the past and found them very 
helpful.  My training philosophy/system has evolved from information that I 
have gleaned from various sources (some could have been from your writing). 
 Essentially, I believe that once you have a "long-slow-distance" base on 
your endurance horse, the best use of your training time and miles is to 
stress the horse with anaerobic intervals in order to raise the horse's 
aerobic threshold.  I would like to refine my methods a little more than I 
currently do and maybe apply a couple of principles you discussed recently 
on this E-mail list.
(The scenario below after QUESTION #3 is rather long so if you'd rather not 
muddle through it, please just answer questions #1, #2 & #3.  Thanks!)
QUESTION #1
My first question regards your statement below.  What is a "good" recovery 
heartrate for 60-90 seconds post anaerobic work at 200-220 bpm?   
Tom Ivers wrote-----------------------------------------------------------
There is a plateau that the recovering heartrate will hit at about 60-90
seconds after the work has ceased. It is this "recovery" heartrate that can
give you a reasonable estimate of the level of anaerobic work performed by
the horse. Other factors come into play when simply sitting waiting for
heartrate to drop below 100--body heat, for example, and
agitation/discomfort.
-------------------------------------------------------------------------
QUESTION #2
>From your statement below were you inferring that "bursts of near-maximal 
effort" should be performed in TRAINING or in COMPETITION?
Tom Ivers also wrote------------------------------------------------------
Again, anaerobic threshold is not a consideration in an event like 
this--and
in fact, crossing that threshold with bursts of near-maximal effort may be
beneficial. The problems are going to be muscle substrate depletion and 
body
heat. Eventually, alkalosis (too much oxygen due to rapid breathing). 
--------------------------------------------------------------------------
QUESTION #3
Does interval training w/"bursts of near-maximal effort" actually raise the 
anaerobic threshold or does is just develop a more efficient system to 
metabolize lactic acid?
SCENARIO -- long--
Here is my interval training scenario at our current fitness level.  11yo, 
14.3h, 950#, Anglo-Arab, mare, 1800 miles of competition, carrying 175 lbs, 
resting pulse 28.   
Step 1)  15 min. warm-up with one mile of walk, ~ two miles of trot at HR 
120-140, relatively flat terrain with a few hills and gullies.
This brings us to the base of the "training hill" which consists of a 3.5 
mile dirt road up a mountain with 2000 feet of elevation change.  It is not 
a simple 11% grade, but seven steep (~25-30%) grades with lesser grades and 
a few downhills between.
Step 2)  gallop intervals with walk recoveries and trot aerobic works 
between--
  a)  1st steep grade ~ gallop 1/4 mile, max HR 180-200, walk to recovery 
of 120 in 1 min. or less (I'm still on board), trot uphill to next steep 
grade at HR 120-160
  b)  2nd steep grade ~ same as 1st
  c)  3rd steep grade ~ same as 1&2
  d)  4th steep grade ~ 1/4 mile, this grade is steeper, max HR 200-220, 
walk to recovery of 120 in 2 min. or less (I'm still on board),  trot up 
and down hill for about 1 mile @ HR 120-150.
  e)  5th steep grade ~ 1/4 mile, this grade is STEEPER STILL, max HR 
200-220, walk to recovery of 120 in 2 min. or less (I'm still on board),  
trot up and down hill for about 1/4 mile @ HR 120-150.
  f)  6th and 7th grades ~ 3/4 mile, 6th grade is a KILLER HILL 1/4 mile, 
HR 210-220+, no stopping -- gallop to next grade on flat and a little down 
HR 180, -- gallop last grade 1/4 mile, HR 220.
  g)  dismount HR @ 180, @ 1 min HR ~ 130, @ 2 min HR ~ 100.
Step 2 takes 20-25 min. to cover the 3.5 miles of hill @ gallop with walk 
and trot intervals (depending on ambient conditions and my mare's fitness 
level).
Step 3) Recovery -- by now I've loosened the girth and removed the bit and 
started leading her back down the hill, takes about 5-10 min., for the mare 
to stop "blowing" & HR @ ~ 80, DO ambient conditions.  Takes a total of 
20-30 min. to reach Vet Check recovery of HR 64, DO ambient conditions & 
fitness.  (I've also tried recovery without walking back down the hill but 
just strolling on the flat -- recovery time is about the same.  Also, seems 
to make no difference whether I let her graze or not.)
QUESTION #4
Are these the type of "bursts of near-maximal effort"  you had in mind?  
Too many? Too few?
Thanks for the opinions!
Linda Van Ceylon
lvanceylon@vines.colostate.edu