skeletal muscles and liver are optimal as the
event starts. Skeletal muscle cells will depend
both on endogenous glycogen stores as well as
carbohydrate delivered by the blood as glucose.
The nervous system depends totally on glucose
obtained from the blood for its completely
aerobic metabolism. Insufficient glucose for the
nervous system results in loss of control and
coordination of the muscles and the movements.
There is a small amount of glucose circulating in
the blood as an event starts, but the blood
glucose level must be maintained from glycogen
stored in the liver. Low glycogen concentrations
in the skeletal muscle cells reduce an athlete’s
capacity for power production. Low blood
glucose can therefore adversely affect both
nervous system function and muscle function.
The athlete’s conditioning programme must
be planned with great care and appreciation for
the specific demands of each event or sport activ-
ity. The force, power, metabolic and associated
nutritional demands of both competition and the
conditioning programmes involve great differ-
ences among such varied activities as Olympic
weightlifting, high jumping, 100-m running,
400-m swimming, tennis, field hockey, basket-
ball, road cycling, cross-country skiing and
marathon running.
16 nutrition and exercise
References
Åstrand, P.-O. & Rodahl, K. (1986) Textbook of Work
Physiology. McGraw-Hill, New York.
Bureau International des Poids et Mésures (1977) Le
Système International d’Unités (SI), 3rd edn. Sèvres,
France.
Cavanagh, P.R. (1988) On ‘muscle action’ vs. ‘muscle
contraction.’Journal of Biomechanics 22 , 69.
DeLorme, T.L. (1945) Restoration of muscle power by
heavy resistance exercises. Journal of Bone and Joint
Surgery 27 , 645–667.
Fleck, S.J. & Kraemer, W.J. (1997) Designing Resistance
Training Programs.Human Kinetics, Champaign, IL.
Knuttgen, H.G. & Kraemer, W.J. (1987) Terminology
and measurement in exercise performance. Journal of
Applied Sports Science Research 1 , 1–10.
Komi, P.V. (ed.) (1992) Strength and Power in Sport.
Blackwell Scientific Publications, Oxford.Further reading
Dirix, A., Knuttgen, H.G. & Tittel, K. (eds) (1992) The
Olympic Book of Sports Medicine. Blackwell Scientific
Publications, Oxford.
Komi, P.V. & Knuttgen, H.G. (1996) Sport science and
modern training. In Sports Science Studies, Vol. 8, pp.
44–62. Verlag Karl Hofmann, Schorndorf.
Shephard, R.J. & Åstrand, P.-O. (eds) (1992) Endurance
in Sport. Blackwell Scientific Publications, Oxford.