By Marty Gaal
http://www.usatriathlon.org/resources/multisport-zone/multisport-lab/understanding-lactate-threshold-heart-rate-training
Two
fundamental concepts for improvement in endurance racing and training
involve:
- Increasing your aerobic endurance
- Improving your lactate threshold heart rate (LTHR)
The first is accomplished by completing workouts involving aerobic exercises
(swimming, biking, running, rowing, cross-country skiing, and so on) at an easy
to moderate effort level. Over time, your ability to continue the exercise will
improve through physiological adaptations to the specific exercise.
For
example, if you are currently untrained or out of shape, a 30 minute bike ride
may be challenging and near the limit of your ability. If you go and ride 20-30
minutes three times per week for a few weeks, your body will adapt by increasing
blood flow to the muscles being used, increasing muscle size (hypertrophy) and
strength, improving blood flow through a process called capillarization (tiny
veins to the muscles), increased mitochondrial density (aerobic enzymes) in the
muscles and a few other geeky details.
All these result in the ability
to use oxygen as the main exercise energy source more efficiently, meaning you
can now ride longer and not be tired at 30 minutes.
The second, improving
lactate threshold, is accomplished by completing easier training sessions like
the above, plus including more challenging workouts that raise your heart rate.
Lactate threshold is the point in exercise where your body produces more
blood lactate than it can reabsorb (and manage other lactate by-products - look
up "hydrogen & lactate & exercise" if you want some
exciting reading) on a continuous basis. Well-trained athletes can usually
continue exercise at just below lactate threshold for about an hour. Go over
lactate threshold though, and that time drops to 5-6 minutes.
For most
people, the lactate threshold is about 20 heart beats per minute above the
steady aerobic threshold. Any aerobic exercise, generally speaking, will help
both points go a bit higher. But there is a point of diminishing returns. If you
don't also include workouts that challenge your system by going just below to
above your current lactate threshold, you will not maximize your ability in
short distance to long distance events.
The secret or goal with lactate
threshold training is to raise your threshold point to as close as possible to
your maximum heart rate, and improve your ability to withstand that discomfort
(if it was easy everyone would do it). If you never do harder workouts, then
your lactate threshold will always remain below your possible maximum lactate
threshold.
Raising your lactate threshold point, for the most part, will
bring your steady aerobic threshold point up with it (as the 20 bpm relationship
is fairly constant).
So if you're training for an Ironman, from a
specificity standpoint you want to train that steady aerobic threshold because
that is more or less your race pace. But you should include some LT training as
well to raise that point a bit higher.
If you're training for a sprint or
Olympic distance race, from a specificity standpoint you want to work more on
that 2nd threshold. You should include quite a bit of aerobic steady training as
that provides your foundation.
So you’re probably thinking: how do I
find my threshold and what are some workouts ideas?
Finding it:
Warm
up 15-20 minutes then 30 minutes "race effort" — as hard as you can go for 30
minutes. Take your heart rate average for the last 20 minutes. Bingo, you have
your LTHR.
Biking:
2 x 20 minutes just below lactate threshold with 5
minutes easy between
5 x 5 minutes at lactate threshold with 3 minutes easy
in between
5 x 3 minutes over lactate threshold with 3-5 minutes easy in
between
8 x 1 minute well over lactate threshold with 2-3 minutes easy
between
Running:
2 x 10 to 15 minutes (1 to 2 miles) just below
threshold with 5 minutes easy between
4 or 5 x 4 minutes (800-1200m) at
threshold with 2-3 minutes easy between
5 to 6 x 3 minutes (600-800m) over
threshold with 3 minutes easy between
8 x 1 minute over threshold with 1
minute easy between
Generally speaking, running causes more breakdown so total "hard" training
volume should not be more than 10-15 percent of weekly
mileage.
Swimming:
4 x 400s just below threshold with 1-2 minute
between each
12 to 16 x 100s at threshold with 10-15 seconds rest between
each
8 x 50 over threshold with 30 seconds to 1 minute rest between
each
There are plenty of other workouts, but the theme here is:
- sub-threshold workouts take 10-25 percent interval rest
- at-threshold workouts take 50-75 percent interval rest
- over-threshold workouts take 100-200 percent interval rest
In general, advanced athletes can do more repetitions and/or take less rest; beginner athletes should do less repetitions and take more rest.
Marty Gaal, NSCA-certified strength and conditioning specialist, is a USA
Triathlon and USA Track and Field certified coach. He and his wife Brianne work
with amateur athletes spanning the range of athletic experience and age through
their company One Step Beyond in Cary, N.C. You can read about all their
services and upcoming clinics at www.osbmultisport.com.