Introduction
Competitive bodybuilders are judged
on the basis of muscular size, shape, definition, density, proportion,
and visual presentation (International Federation of Bodybuilders,
1987). Bodybuilders generally train for muscular size during
the off season and reduce body fat several weeks or months before
competition (Elliot, Goldberg, Kuehl, & Catlin, 1987; Hickson,
Johnson, Lee, & Sidor, 1990; Balon, Horowitz, & Fitzsimmons,
1992). The body fat of male competitive bodybuilders during the
off season have been measured at 9.8% (Hickson, Johnson, Lee,
& Sidor, 1990),13.1 ±2.8% (Kleiner, Calabrese, Fielder,
Naito, & Skibinski, 1989), 9.3 ±0.75% (Katch, Katch,
Moffatt, & Gittleson, 1980). The relative absence of subcutaneous
fat can enhance the appearance muscular development by revealing
the size, shape, and striations of the underlying muscles. In
effort to reduce body fat and maintain lean body weight, bodybuilders
typically employ restrictive dietary practices, intense training,
and the self-administion of pharmaceuticals.
Off Season Diet
Kliener (1989) found competitive bodybuilders who consumed
an average of 5739 ±2500 kcalories (2451-19760 kcal) when
not preparing for competition. One subject consumed only 2451
kcalories, where as another subject reported consuming 19760
kcalories; 1290 gm of protein, 2443 gm of carbohydrate, and 663
gm of fat. Some subjects reported eating every two hours and
many claimed to awaken to eat during the night. This extreme
kcalorie consumption is rare in the literature since Kliener
(1990) gave inaccurate reference to bodybuilders who reported
consuming 17,333 (+/- 4554) kcalories daily (Kleiner, Bazzarre,
& Litchford, 1990). In the actual study, they documented
the daily consumption of 17,333 kilojoules (4127 kcal), not 17,333
kilocalories as reported (Faber, Benade´, & van Eck,
1986). The most extreme protein intake reported in the research
in 1989 was 3.5 g/kg/day. This amounted to 20% of the subject's
daily caloric intake (Paul, 1989; Dragan, Vasiliu, & Georgescu,
1987).
Bodybuiders have been known to rapidly gain weigh prior to
competition after breaking their precontest diet (Hildebrand,
Saldanha, & Endres, 1989; Hickson, Johnson, Lee, & Sidor,
1990). Overfeeding has been shown to lead to an increase of lean
body mass possibly as a result of increased plasma somatomedin-C,
testosterone, and insulin (Forbes, Brown, Welle, & Underwood,
1989). Insulin facilitates and increases the transport of glucose
and amino acid into muscle cells. Insulin can also stimulate
the synthesis and storage of cellular protein and glycogen in
muscle cells (Di Pasquale, 1993). Although insulin's effect on
amino acid uptake into the cell may not be indicative of increased
muscle mass (Florini, 1987), insulin may permit maximum protein
synthesis to occur in idea physiological situations (Di Pasquale,
1993). Insulin and other anabolic compounds may act synergistically
to produce significant anticatabolic and anabolic effects (Di
Pasquale, 1993). Intercellular amino acid is essential to the
action of anabolic steroid's role in protein synthesis.
It must be noted, though, insulin increases lipoprotien lipase
action and can enhance the synthesis and storage of triglycerides
in fat cells (Di Pasquale, 1993). Anabolic steroids may play
a physiological role in the regulation of fatty acid oxidation
in liver and fast twitch muscle mitochondria even in the absence
of intense physical training (Guzman, Saborido, Castro, Molano,
& Megias, 1991). It has been argued that a high fat diet
has a positive effect on muscle growth (Di Pasquale, 1992).
Muscle glycogen synthesis is greatest within 2 hours proceeding
exercise. Exercise increases the muscle's sensitivity to insulin,
predominately, during the 4 to 6 hours after exercise. During
this time, muscle glycogen synthesis has been shown to be greater
with ingestion of simple as compared with complex carbohydrates.
After which, muscle glycogen can be resynthesized near pre-exercise
levels within 24 hours, equivalently with either carbohydrate
form (Friedman, Neufer, & Dohm, 1991). After 24 hours, muscle
glycogen can increase very gradually, succeeding normal levels
over the next few days (Ivy, 1991).
Many bodybuiding athletes believe nutritional suppliments
are necessary for optimal progress, although many claims made
for commercially marketed supplements for bodybuilding athletes
are not supported by current research (Grunewald & Baily,
1993).
|
|