- The effectiveness of caffeine may not be as great in
habitual users or in hot humid environments.
SAFETY
- In normal doses (5–8 mg/kg) caffeine appears safe
and produces a few side effects such as diarrhea,
insomnia, restlessness, and anxiety. - Caffeine does not appear to increase risk for heat-
stroke or compromise cardiovascular activity in
endurance performance (Pasman et al, 1995).
•Very high doses, over 10 mg/kg, may cause seizures
and overdosing may lead to death.
LEGAL
- Caffeine, although ergogenic at 5–10 mg/kg, is not com-
pletely banned by the IOC and NCAA. Habitual users
may consume their usual caffeine in small amounts.
Ingestion of around 7 mg/kg, roughly two cups of
coffee, produce urinary levels close to the limit of
12 mcg/mL for the IOC. The NCAA levels are slightly
more liberal at 15 mcg/mL (American College of Sports
Medicine, 1987; U.S. Antidoping Agency, 2003).
CLENBUTEROL AND BETA AGONISTS
EFFICACY
- Clenbuterol and other beta 2 agonists like salmeterol
and albuterol are used widely as bronchodilators for
the treatment of many types of asthma including exer-
cise induced asthma. - There are no human studies to support athlete’s use of
clenbuterol for their potential anabolic effects, either
as an anabolic steroid substitute or to prevent some of
the muscle loss after cessation of anabolic steroids.
Animal studies have shown that clenbuterol in high
doses increases lean body mass and decreases adipose
tissue (Prather et al, 1995).
•However, a study on a relative drug, salbutamol, showed
increased quadriceps and hamstring strength, while
another showed that 6 weeks of oral albuterol may aug-
ment strength gains in isokinetic strength training of the
knee (Martineau et al, 1992; Caruso et al, 1995). - These studies taken together imply that there may be
an ergogenic effect of prolonged oral beta 2 agonists
on strength, but no ergogenic effect of short term
administration of inhaled medicines. Confirmatory
studies on humans remain to be done regarding their
potential anabolic effects.
SAFETY- Side effects of beta 2 agonists are common and
include tachycardia, tremor, palpitations, anxiety,
headache, anorexia, and insomnia. Serious side
effects include dysrhythmias, cardiac muscle hyper-
trophy, myocardial infarction, or stroke (Prather et al,
1995).
LEGAL- Because of its potential ergogenic effect clenbuterol
in all its forms and all oral beta 2 agonists are banned
by the IOC and NCAA (American College of Sports
Medicine, 1987; U.S. Antidoping Agency, 2003). - Advances in testing may eventually enable detection
of these drugs through hair analysis. - Clenbuterol is not FDA approved.
- It is interesting to note there was an increase in the
percentage of U.S. Olympic athletes with exercise
induced asthma from 10% in the 1984 Summer
Olympics to over 20% in the 1996 Summer Olympics,
thus greatly increasing the number of athletes who
can “legally” use these products (Weiler, Layton, and
Hunt, 1998).
COENZYME Q10EFFICACY- Coenzyme Q10 (CoQ10), also called ubiquinone, is a
part of the electron transport system and functions as
an antioxidant. Endurance runners sometimes use
CoQ10 and other antioxidants. - In patients with congestive heart failure, CoQ10
improves cardiac function including stroke volume,
ejection fraction, cardiac output, and cardiac index
(although total work output does not appear to be
increased) and may serve a role in postmyocardial
infarction patients (Soja and Mortensen, 1997).
•A double blind Finnish study did show an increase in
anaerobic and aerobic indices in 25 top level cross
country skiers (Snider et al, 1992); however, other
studies examining CoQ10 either alone or in combina-
tion with other antioxidants have not shown any effect
on anaerobic or aerobic performance. More research
is required. - Safety CoQ10 seems safe although there are no long
term studies.
•Legal CoQ10 is not on the list of banned substances
(American College of Sports Medicine, 1987; U.S.
Antidoping Agency, 2003).
422 SECTION 5 • PRINCIPLES OF REHABILITATION