Clean Run - June 2020 - 29

It is the cortisol that helps to assist or
relieve the stress by increasing glucose metabolism, which provides energy for the dog to handle "fight" or
escape ("flight") from the stress.
In situations where there is shortterm stress, cortisol release is beneficial to the dog as it aids them in
handling the stress. However, in situations of chronic stress, cortisol has
been shown to produce many negative effects such as mental fatigue,
aggressive behavior, decreased
growth and reproductive capability, inhibition of the immune system,
and an increased risk of GI issues.
In previous animal studies looking at
the effects of exercise and training,
short-term light or moderate workloads may have minimal changes
on cortisol levels. The rise in cortisol associated with exercise, training, and competition is dependent
on the intensity and duration of the
exertion as well as the fitness of the
dog. Not only does your dog need
the ability to handle the psychological and biological stresses that are
presented on a daily basis, he also
has to weather the additional stress
of their sport. Based on similar challenges in human athletes, there has
been tremendous work performed in
this area. Researchers have identified
techniques, products, supplements,
etc. to help manage this extremely
complicated balance. When looking
from a translational medicine point
of view, many of these may be considered as potential options for our
canine athletes.

Immune System Stress
The immune system is highly complex and provides defense against
attack from pathogenic microorganisms, including viruses, bacteria, fungi, and protozoa. Studies have shown
that exhaustive exercise can lead to
immune deficiencies. This is because
the increased levels of circulating
cortisol have a negative effect on the
blood cells that are needed to protect the immune system. It has been
reported that 15-75% of both innate
June 20 | Clean Run

Stress response system

and acquired immunity decreases transiently in the hours following heavy
exertion. These reports also show that prolonged heavy training sessions decrease immune function by providing an "open window" for infections.
In human sports medicine, there are numerous, recent recommendations that
athletes are following to help maintain a healthy immune system. The seven
items listed below come directly from an incredible article, "Recommendation
to maintain immune health in athletes" by Neil Walsh in the European Journal
of Sport Science.1 These can easily be translated to the canine athlete.
Recommendations for modifying training and recovery activities to maintain
immune health in athletes
1. Manipulate training volume and/or intensity to manage training load
2. Keep the size of increments, both in volume and intensity, to 5-10% per
week; particularly important during winter
3. Increase the frequency of shorter, spike training sessions rather than enduring fewer, longer sessions
4. Implement recovery activities immediately after the most intensive training
sessions
5. Undertake easy-moderate training sessions after each high-intensity session
6. Plan an easier recovery/adaptation week every 2nd or 3rd week of the training cycle"
7. Permit athletes at heightened risk of illness several weeks of active recovery
after completion of a season or major competition
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Clean Run - June 2020

Table of Contents for the Digital Edition of Clean Run - June 2020