Answer:
i think Marco should replace ''ever again'' with ''very often''
Explanation:
''potato chips'' wouldn't really change the sentence, ''this week'' would only lower a few calories but he want to <u>improve</u> his body, and never eating junk food again is probably impossible so the only option left is: ''very often''
Sprinting for 30 seconds during a jog is called a sprint interval. (Fartlek)
The two main parts are the Systemic and Pulmonary
