Final answer:
Physical exercise includes both anabolic and catabolic processes, where catabolic reactions release energy by breaking down glucose, and anabolic reactions use this energy to form proteins for muscle growth and repair, exemplified by running and weightlifting, respectively.
Step-by-step explanation:
Physical exercise involves both anabolic and catabolic processes. During physical activity, our bodies undergo catabolism where glucose is broken down into simpler compounds, which is a process that releases energy. This energy is then used in anabolic processes to synthesize larger molecules such as proteins from smaller ones like amino acids.
An example of a catabolic activity would be running, which uses energy from the breakdown of glucose for muscular contractions. On the other hand, weightlifting is a classic example of anabolic activity, as it stimulates muscle growth and repair, necessitating the synthesis of protein to strengthen and increase muscle mass.
Both sets of reactions are crucial as they not only provide the needed energy for physical activities but also help in recovery and building muscle tissue after exercise, maintaining the balance essential for a healthy metabolism.