If I eat while I'm doing some kind of activity that makes me sweat, I consider it as zero gain as far as calories go.
この場合、次のような言い方ができますよ。
ーIf I eat while I'm doing some kind of activity that makes me sweat, I consider it as zero gain as far as calories go.
「汗をかくことをしながら食べると、カロリーに関してはゼロ摂取と考える」
to consider it as zero gain で「それを全く増えていない(ゼロ)と考慮する」
ご参考まで!