CHAPTER 16 • EXERCISE AND CHRONIC DISEASE 97•Exercise does improve insulin sensitivity in liver,
muscle, and fat cells (Wallberg-Henriksson, 1992).
•A single exercise session has been shown to increase
insulin sensitivity for 16 h (Landry and Allen, 1992).
REDUCED MORBIDITY AND MORTALITY
- Epidemiologic studies demonstrate the benefits of
exercise. One study following male type-1 diabetics
for 20 years shows those who participated in High
School or college sports had lower mortality and
lower incidence of macro vascular disease than seden-
tary counterparts (LaPorte et al, 1986).
IMPROVED SELF ESTEEM
•Exercise has a positive effect on the self-esteem of
diabetic patients and allows many to cope better with
physical and emotional stress.
RENAL DISEASE IN ATHLETES
KIDNEY PROBLEMS ASSOCIATED
WITH EXERCISE
- Dehydration, hyperpyrexia, hyperkalemia, and rhab-
domyolysis may all occur as a result of exercise and
may lead to renal damage (Fields and Fricker, 1997). - Rhabdomyolysis, especially in untrained athletes, can
lead to renal ischemia and nephrotoxins (Olerud,
Homer, and Carrol, 1994).
PREVENTION OF RENAL DISEASE
- Fluids are important in minimizing muscle damage,
promoting myoglobin elimination, and maintaining
renal blood flow. - Prevent rhabdomyolysis through adequate fluid intake,
appropriate carbohydrate intake to avoid glycogen
depletion and avoiding exercising to exhaustion.
THYROID DISEASE IN ATHLETES
HYPOTHYROIDISM
•Hypothyroidism is associated with decreased exercise
tolerance (McAllister, Sansone, and Laughlin, 1995).
- Replacement of thyroxin is the mainstay of treatment.
•Exercise is safe when adequate replacement is main-
tained.
HYPERTHYROIDISM- Hyperthyroidism is associated with decreased exer-
cise tolerance (McAllister, Sansone, and Laughlin,
1995). - Higher blood lactate, depletion of glycogen, and rela-
tive hyperthermia may all contribute to decreased per-
formance (Nazar et al, 1978). - Beta-blockers can be helpful in the treatment of
hyperthyroidism but may have a negative effect on
performance and are banned under Olympic regula-
tions.
•Exercise is safe after appropriate treatment and close
supervision.
OSTEOPOROSIS- The National Osteoporosis Society estimates one in
three women and one in 12 men over the age of 50
will be affected by osteoporosis (Boutaiuti et al,
2000). Additionally, 1.5 million fractures are attribut-
able to osteoporosis each year.
•Exercise at an early age is important to develop ade-
quate bone density. Multiple studies on young men and
women have shown that both resistance and endurance
exercise programs can lead to site-specific increases in
bone mineral density(BMD) (Snow-Harter et al, 1992;
Margulies et al, 1986). BMD is reported to be higher
in athletic young adults than in their sedentary peers
(Kirchner, Lewis, and O’Conner, 1996). - Bone loss in the postmenopausal period can be slowed
by weight bearing and resistance exercise. In a
Cochrane meta-analysis, aerobic exercise, resistance
exercise, and walking were all shown to be more effec-
tive at slowing bone loss at 1 year when compared to
no exercise (Boutaiuti et al, 2000). A majority of stud-
ies show that weight-bearing exercise mainly prevents
bone loss of the lumbar spine but suggest that this may
occur at the femur and forearm as well (Boutaiuti et al,
2000; Wolff et al, 1999; Michel et al, 1991).
•A few studies suggest exercise may increase BMD
even in the postmenopausal state when combined with
other therapy for osteoporosis (Michel et al, 1991).
Multiple studies suggest even if BMD is not
increased, exercise lessens the risk of osteoporotic
fractures by improving balance and muscular strength
(Nelson et al, 1994).
•Exercise goals for individuals with osteoporosis
should include reducing pain, increasing mobility,
improving muscle endurance, balance, and stability in
order to improve the quality of life and reduce the risk
of falling.