16. Seated shoulder press
Press your back against the chair without flattening out the curve in your back. Your goal is to complete 3 sets of 15 reps, with 30-second rest.
STEPS:
1. Hold a 1-liter water bottle in each hand, sit on a chair with back support with your feet firmly on the floor.
2. Bend your elbows and raise your arms to shoulder height till hands are at ear level.
3. Push the bottles up directly over your head, and then lower them back to ear level.