Start of a school sports day. A mother on the sideline cups her hands and screams at her eleven-year-old: "ファイト！"
A visiting English speaker looks around for the other child.
There is no other child. The boy is doing the long jump.
ファイト here means fighting spirit, effort, go for it. It sits beside 頑張って (ganbatte), the standard "do your best", but with more shout in it.
The full version, ファイト一発 (faito ippatsu — roughly "one shot of fighting spirit"), comes from decades of energy drink commercials in which men do dangerous things on cliffs, and it is still yelled at anyone visibly struggling with something heavy.
It is also a good example of how loanwords arrive in Japan through advertising rather than education. A lot of Japanglish is not schoolroom English gone wrong — it is 1970s and 80s copywriting that worked so well it entered the language and stayed.
English encouragement points at the outcome: good luck, you've got this, break a leg. Japanese encouragement points at the effort: ganbatte, faito — do your best, endure it. Nobody is wishing you luck, because luck is not the variable being measured. That difference explains a surprising amount about school, work and sport in this country.