Abstract
In order to test the hypothesis that dietary restriction may have a negative influence
on physiological and psychological adaptation to a judo competition, we examined the
effects of weight loss induced by restricting energy and fluid intake on the physiology,
psychology, and physical performance of judo athletes. Twenty male judoka were randomly
assigned to one of two groups (Group A: called diet, n = 10; height 174.8 ± 1.9 cm,
body weight 75.9 ± 3.1 kg; they were asked to lose ∼ 5 % of their body weight through
self-determined means during the week before the competition; Group B: called control,
n = 10; height 176.4 ± 1.1 cm, body weight 73.3 ± 6.3 kg maintained their body weight
during the week before the competition). A battery of tests was performed during a
baseline period (T1 ), on the morning of a simulated competition (T2 ) and 10 min after the end of the competition (T3 ). The test battery included assessment for body composition, performance tests, evaluation
of mood, determination of metabolic and hormonal responses. Dietary data were collected
using a 7-day diet record. The nutrient analysis indicated that all the athletes followed
a low carbohydrate diet whatever the period of the investigation. For the Group A,
the food restriction (- 4 MJ per day) resulted in significant decreases of the body
weight and altered the mood by increasing Fatigue, Tension and decreasing Vigour.
Dietary restriction had also a significant influence on metabolic and endocrine parameters
and was associated with poor performance. After the competition, significant decreases
of the levels in testosterone, T/C ratio, alkali reserve, and free fatty acid were
observed in both groups, whereas the plasma concentrations in insulin, ammonia, urea,
and uric acid were increased. In conclusion, our results suggest that the combination
of energy restriction and intense exercise training, which causes weight reduction
before a competition, adversely affects the physiology and psychology of judo athletes
and impairs physical performance before the competition. Our data are the first to
demonstrate that a competition including five 5-min bouts induced the same changes
of physiological and psychological variables and performance whatever the dietary
intake (dietary restriction or not) during the seven days before the competition.
Key words
Weight loss - performance - hormonal status - metabolites - psychological state
References
Thyroid function and exercise. Warren MR, Constantini NW Contemporary Endocrinology: Sports Endocrinology. Totowa;
Humana Press 2000 Adrenal androgens. DeGroot L Endocrinology, 1836 - 1852. Philadelphia; W. B. Saunders Co 1995 Physiologie de l'exercice musculaire et nutrition du sportif. Brunet-Guedj E, Comtet B, Genety J Abrégé de médecine du sport. 6 éd. Paris; Masson
2000
efilaire@nat.fr
