Zeferino, mutambi wemuOlympic katatu, akatanga kukwikwidza kuCape Verde mumusangano wakaitwa kuMaia, kuPortugal achiisa rekodhi yenyika mumakwikwi emamita 3000 achiripo nanhasi. Gore rakatevera pa 1996 Summer Olympics muAtlanta, Zeferino akaita nhoroondo pamwe chete naHenry Andrade naIsménia do Frederico nokuva vatambi vokutanga kumiririra rudzi ruduku rweAfrica paMitambo yeOlympic. Munhangemutange yemarathon yevarume akapedza ari wechi94 nenguva ya2:34:13. Gore rakatevera racho akakwikwidza mu1997 World Championships, achipedza ari wechi37 mumarathon nenguva ya2:25:56. Makore maviri gare gare munaFebruary 1999, Zeferino akarekodha nguva yake yakanakisisa mumarathon paSevilla Marathon kupedzisa muna 2: 23: 16. Mwedzi mitanhatu gare gare pa1999 Championships, akapedza marathon zvishoma zvishoma mu2:26:03 iyo yakamuisa panzvimbo ye39. Pa 2000 Summer Olympics muSydney, Zeferino akavandudza nguva uye nzvimbo kubva makore mana apfuura kuyambuka mutsetse munzvimbo yechi67 munguva ye2:29:46. Gore rakatevera, akapedza pa 2001 World Championships, kwaakapedza marathon ari panzvimbo yechi51 mu 2:32:46. Mujaho wokupedzisira waZeferino wakanga uri marathon
paMitambo yeAthens ya2004 apo aiva nemakore 38, akapedza ari wechi78 nenguva ya2:36:22.