The aim of this study was to compare the rehydration potential of a carbohydrate-electrolyte beverage with several varieties of milk following exercise-induced fluid losses. Fifteen male participants (age 24.9 [+ or -] 5.5 years, height 179.3 [+ or -] 4.9 cm, body mass 75.8 [+ or -] 6.6 kg (mean [+ or -] SD)) lost 2.0% [+ or -] 0.2% body mass through intermittent cycling before consuming a different beverage on 4 separate occasions. Drinks included cow's milk (286 kJ x 100 [mL.sup.-1]), soy milk (273 kJ x 100 [mL.sup.-1]), a milk-based liquid meal supplement (Sustagen Sport (Nestle); 417 kJ x 100 [mL.sup.-1]), and a sports drink (Powerade (Coca Cola Ltd); 129 kJ x 100 [mL.sup.-1]). Beverages were consumed over 1 h in volumes equivalent to 150% of body mass loss. Body mass, blood and urine samples, and measures of gastrointestinal tolerance were obtained before and hourly for 4 h after beverage consumption. Net body mass at the conclusion of each trial was significantly less with Powerade (-1.37 [+ or -] 0.3 kg) than with cow's milk (-0.92 [+ or -] 0.48 kg), soy milk (-0.78 [+ or -] 0.37 kg), and Sustagen Sport (-0.48 [+ or -] 0.39 kg). Net body mass was also significantly greater for Sustagen Sport compared with cow's milk trials, but not soy milk. Upon completion of trials, the percentage of beverage retained was Sustagen Sport 65.1% [+ or -] 14.7%, soy milk 46.9% [+ or -] 19.9%, cow's milk 40.0% [+ or -] 24.9%, and Powerade 16.6% [+ or -] 16.5%. Changes in plasma volume and electrolytes were unaffected by drink treatment. Subjective ratings of bloating and fullness were higher during all milk trials compared with Powerade whereas ratings of overall thirst were not different between beverages. Milk-based drinks are more effective rehydration options compared with traditional sports drinks. The additional energy, protein, and sodium in a milkbased liquid meal supplement facilitate superior fluid recovery following exercise. Key words: hydration, diet, sports nutrition, exercise. Cette etude se propose de comparer le potentiel de rehydratation d'une boisson contenant des sucres et des electrolytes a quelques varietes de boissons lactees a la suite de la perte de liquides corporels suscitee par l'exercice physique. Quinze hommes (moyenne [+ or -] ecart-type : 24,9 [+ or -] 5,5 ans, 179,3 [+ or -] 4,9 cm, 75,8 [+ or -] 6,6 kg) perdent 2,0 [+ or -] 0,2 % de leur masse corporelle en pedalant par intermittence prealablement a la consommation de boissons differentes en quatre occasions distinctes. Les liquides consommees sont : lait de vache (286 kJ x 100 [mL.sup.-1]), lait de soja (273 kJ x 100 [mL.sup.-1]), supplement de repas liquide a base de lait (Sustagen Sport; 417 kJ x 100 [mL.sup.-1]) et boisson pour sportif (Powerade; 129 kJ x 100 [mL.sup.-1]). Les sujets consomment en 1h des quantites equivalant a 150 % de la masse corporelle perdue. On evalue la masse corporelle, des echantillons de sang et d'urine et la tolerance gastro-intestinale avant et aux heures pendant quatre heures apres la consommation de la boisson. A la fin de chaque essai, la masse corporelle nette est significativement inferieure dans la condition Powerade (-1,37 [+ or -] 0,3 kg) comparativement aux autres conditions : lait de vache (-0,92 [+ or -] 0,48 kg), lait de soja (-0,78 [+ or -] 0,37 kg) et Sustagen Sport (-0,48 [+ or -] 0,39 kg). La masse corporelle est aussi significativement superieure dans la condition Sustagen Sport comparativement a la condition lait de vache, mais pas par rapport a la condition lait de soja. A la fin de chacun des essais, le pourcentage de boisson retenue est: Sustagen Sport 65,1 [+ or -] 14,7 %, lait de soja 46,9 [+ or -] 19,9 %, lait de vache 40,0 [+ or -] 24,9 % et Powerade 16,6 [+ or -] 16,5 %. La variation du volume plasmatique et de la concentration des electrolytes n'est pas affectee par le genre de boisson. Les sensations de ballonnement et de satiete sont plus marquees dans toutes les conditions comprenant du lait comparativement a la condition Powerade; les sensations de soif ne different pas d'une condition a l'autre. Les boissons a base de lait sont plus efficaces sur le plan de la rehydratation comparativement aux boissons traditionnelles pour sportifs. L'energie, les proteines et le sodium en plus contenus dans les supplements liquides a base de lait procurent une plus grande recuperation des fluides apres un exercice. [Traduit par le Redaction] Mots-cles: hydratation, diete, nutrition sportive, exercice physique.