Five - time Olympic champion tweets photo of 10,000-calorie meal . Elite swimmers require so much exercise because of their size and grueling training schedule . Most swimmers requiring endurance are a lot smaller , says UK nutrition expert . ` ` Messing your diet up can really affect performance , '' ' ##ham says .
Five-time Olympic champion tweets photo of 10,000-calorie meal . Elite swimmers require so much energy because of their size and grueling training schedule . Most athletes requiring endurance are a lot smaller , says UK nutrition expert . `` Messing your diet up can really impair performance , '' Lewis James says .