an athlete who competes in an event that includes seven different sports

Jessica Ennis became the best heptathlete in Great Britain. 杰西卡·恩尼斯成为英国最好的七项全能运动员。

Heptathletes have seven events, which adds up to lots of baggage and equipment. 七项全能运动员有七项赛事，这增加了很多行李和设备。