I'm worried about my health.

1. Why don't you go to a hodpital and have a health-checkup.
2. Why don't you lift weights every day?
3. Why don't you jump rope every evening?
4. Why don't you jog every morning?
5. To build a muscle, why don't you use barbells? Lift barbells from time to time.
6. Why don't you go on a hike on Weekends?
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Would you check the answers? Are they grammatical? Correct any errors, please.

1 - 4 are fine.

5 - You want to build just one muscle? "a muscle" is one. Lifting weights will strengthen more than one. "musles" would be better than "a muscle".
6 - weelends is not capitalized. It's a common noun, not a proper noun.

Sure! I can check the answers for you. Here are the corrected versions of the statements:

1. Why don't you go to a hospital and have a health checkup?
2. Why don't you lift weights every day?
3. Why don't you jump rope every evening?
4. Why don't you jog every morning?
5. To build muscle, why don't you use barbells? Lift barbells from time to time.
6. Why don't you go hiking on weekends?

These sentences are grammatically correct and convey the meaning effectively.