Fill in the gaps with the verb in brackets using the past perfect continuous.
Example: Sam gained weight because he _______ for 2 years. (overeat)
Answer: Sam gained weight because he had been overeating for 2 years.
1) When the doctor told him his liver was seriously bad, he ___________ mostly hamburgers for a month. (eat)
2) Scarlett came into the room panting. She __________ round the park. (jog)
3) He was tired because he _______ so hard. (exercise)