October 24, 2019

By Herman Bonner, Communications
Specialist, Firstbeat

Physiologists, sports scientists and trainers have long used
training load monitoring as a frontline tool to help elite athletes efficiently
maximize their potential and minimize injury risks. In recent years, the
ability to record the impact of your activities has become increasingly
available with GPS training watches, smartwatches, cycling computers and other
fitness devices.

In this interview, physiologist Aki Pulkkinen, M.Sc., Firstbeat
co-founder and current head of consumer products, explains the background of training
load and how the insight it provides can help you reach your own personal
fitness and performance goals.

What exactly is training load and what is it measuring?

A
fundamental principle of exercise is that physical activity strains your body,
your body recovers from the stress of exercise and then it comes back stronger.
What training load allows you to see
and track the amount of strain placed on your body as a result of your recorded
activities over time. The ultimate goal and real opportunity here is the
possibility of better, more scientific load management strategies at every
level and at every stage of your training career. It’s about being able to
train harder and pushing yourself to the limit, confident that you aren’t going
over the edge or past the point of productive effort.

A
big challenge toward quantifying physical activity in a meaningful way is the
fact that the workouts you do have different durations, intensity levels vary
from one moment to the next and you can exercise via different modalities. You
can run. You can cycle, swim, or whatever. The possibilities are practically
endless. The fact that training load reveals the real impact your activities
have on you, regardless of the structure of your workout or the type exercise
you are doing, makes it a very effective tool for providing insight into
training process.

So how do you measure the impact of an activity? What’s
the science in play?

The
training load data that you get from your device is based on mathematical modeling
of heart rate and other performance data to plot the accumulation of a
physiological measure called EPOC. For those who might be
unfamiliar, EPOC is an acronym for excess post-exercise oxygen consumption.
It’s the amount of oxygen your body will utilize after a challenging
performance to restore itself and return to its normal, balanced resting condition.
EPOC is generally accepted as the best way to measure the degree of homeostasis
disturbance produced by your activities.

To
put it another way, it accurately reflects the amount of stress placed on your
body from exercise. So that’s the scientific basis of your training load feedback.

Why is training load important to individual athletes
like runners? How would I use that information to change my routines and
training activities?

The
ability to quantify the activities in terms of the amount of strain placed on
your body opens the possibility of truly personalized training guidance and
feedback.

A
major advantage of seeing the load or impact of from all your various
activities in a single place is that you can make sure you are active enough
and challenging yourself appropriately. If you exercise too much, you will
become excessively fatigued, which is counterproductive, and it increases
injury risk and can eventually lead to overtraining syndrome. And obviously if
you aren’t working hard enough, then you won’t improve.

At
the start of a new training program, coming back from a break or returning from
injury, you can work your way up to heavier workloads in a smarter way, safely
applying incrementally larger loads over time. It’s one less thing to worry
about, and it offers the perfect perspective for seeing progress, with a steady
lens for understanding and interpreting how you feel along the way.

What kind of numbers should I be trying to hit for my
weekly training load?

Your
watch gives you a number that is your weekly training load, and it’s nice to
have a number that you can follow. Perhaps more importantly, your watch also
shows a dial gauge so that you can see your current load relative to where you
should be. The optimal range for training load is in the middle. If you are on
the right of that you are too high, and on the left then your load is too
light.

You
can always see where you are now and adjust accordingly. When you see that you
are pushing toward the upper limit your optimal range, you know that pushing
yourself any harder would likely be counterproductive. If you slide down toward
the lower end of the optimal zone and you can see that it’s time for a bigger
challenge.

If
you watch the optimal range for your training load carefully, you will notice
that as your [VO2 max] fitness improves, the
optimal range tilts to the right. This means that your fitness level has
increased and now you can tolerate a greater training stress….