I believe it’s D. It’s not A because when you use your muscles you’re getting micro tears that repair and grow.
Answer:
Explanation:the quality or state of being intense especially : extreme degree of strength, force, energy, or feeling. 2 : the magnitude of a quantity (such as force or energy) per unit (as of area, charge, mass, or time)
The answer is C. using your head
Marathon’s consist of running/jogging/sprinting long distances, so first off it would be a good idea to increase stamina, which would be done by jogging everyday, increasing your distance everyday. Stretch your calf muscles upper leg muscles to avoid cramps while running too.