Physical Strength, Physical Power, Stamina, Endurance
noun
You have your body power. This is just another way to say physical strength. Watch out, if you use too much of your physical strength you may run out of physical stamina and endurance completely! They're tied together, so make sure to pace yourself.
たいりょく
This is a jukugo word, which usually means on'yomi readings from the kanji. Since 力 has two on'yomi readings, here's a mnemonic to help you remember which one to use: Your physical strength and stamina are tied together with a tie lock (たいりょく). That's a lock made of ties that ties your strength and stamina up together, making it much easier to pace yourself.
お父さんは体力がない。
Dad doesn't have much endurance.
体力アップのためにランニングを一日一回してます。
I run once a day to improve my stamina.
去年の体力と今の体力は、大体同じです。
My physical strength last year and my current strength are about the same.