Rubuta ci gaba don wannan sakin layi - Khalifa ya yi gasa ga Mauritania a wasannin Olympics na bazara guda biyu, da farko a Wasannin Olympics na 1988, inda ya yi gasa a tseren mita 5000 kuma ya gama na 17 a zagayensa, amma bai cancanci zuwa zagaye na gaba ba. Shekaru hudu bayan haka a gasar Olympics ta 1992 ya shiga marathon
amma bai gama karatun ba.