It's no surprise that your body would get tired after working out ○ consecutive days.
Of course your body would get tired if you worked out ○ days in a row.
ご質問ありがとうございます。
① "It's no surprise that your body would get tired"＝「あなたの体が疲れるのは当然」
"after working out ○ consecutive days."＝「○日連続に運動をした後なら」
② "Of course your body would get tired"＝「もちろんあなたの体は疲労するでしょう」
"if you worked out ○ days in a row."=「もし○日続けて運動をしたら」
ご参考に。
It's only natural that your body is so tired after exercising 5 days straight.
Anyone would be tired after exercising 5 days in a row.
この場合、次のような言い方ができますよ。
ーIt's only natural that your body is so tired after exercising 5 days straight.
「5日続けて運動したら体が疲れるのは当たり前だよ」
5 days straight で「5日間続けて」
ーAnyone would be tired after exercising 5 days in a row.
「誰でも5日連続で運動したら疲れるよ」
5 days in a row で「5日連続で」
ご参考まで！
アメリカ合衆国 
カナダ 
