Page 13 - Summer 2020

than heat dissipation. 3,12,13 Able-bodied
athletes dissipate heat by increasing sweat
production and increasing cutaneous
blood flow, and both of these processes
are driven by the sympathetic nervous
3
system. Unfortunately, spinal cord
injury athletes have a blunted heat
dissipation response corresponding to
the level of their spinal cord injury because
the sympathetic nervous system fibers
10
originate from T1 through T5. As a result,
athletes with tetraplegia (cervical injury)
have no sympathetic nervous system,
so they have absent or reduced sweating
capacity, resulting in continual increases
in body temperature during continuous
submaximal exercise in both cool and warm
conditions. Paraplegic athletes (thoracic
3
and lumbar level injury) are at lower risk for
heat injury compared to tetraplegic patients
due to, at least, partial preservation of the
sympathetic nervous system, depending
upon the level of injury. 3
There are several approaches used to
diminish heat strain, including various
cooling techniques, heat acclimatization,
and heat acclimation (HA). Cooling
strategies such as water sprays and
cooling garments have been shown to
provide some benefit in spinal cord
injury athletes, but many of these
studies demonstrating this effectiveness
were performed in non-competitive
situations. Heat acclimatization uses
3
natural conditions and heat acclimation
uses artificial conditions to produce
favorable physiologic adaptations to
heat stress. Both heat acclimation and
3
acclimatization occur over 5 to 14 days
and result in the following physiologic
adaptations: reduced core temperature
at rest, reduced skin temperature, for gland and local sweat rates. One recent Mental Health
3
increased skin blood flow, and increased study compared the effectiveness of mixed It is recognized that elite athletes are
3
sweat rates at a given exercise intensity. active and passive HA in Paralympic and
However, as discussed above, spinal cord able-bodied athletes. The investigation at risk for psychologic distress due to
13
injury athletes have reduced sweating found that Paralympic athletes are the demands and expectations placed
7
capacity and dynamic skin flow changes capable of partial HA, although not to on them. And, it has been theorized
below their injured level and, depending the extent as able-bodied athletes with that there may be even greater risk for
on the level of injury, have significantly lowered core temperature and blood psychologic distress for Paralympic
decreased available body surface area lactate concentration and increased athletes due to other barriers not
7,14
(as low as 50 percent) for sweating. 3 plasma volume expansion in both groups. experienced by able-bodied athletes.
13
To compensate for the lack of total sweat However, only the able-bodied athletes were However, surprisingly, there has been a
glands available, these athletes can improve able to increase their sweat rates and lower paucity of literature evaluating psychologic
heat dissipation by increasing sweat output their skin temperatures with the HA. and behavioral distress in Paralympic
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Summer 2020, Issue 3 | sportsmed.org 11 