[One-arm rowing] mainly exercises the back muscles.

You only need to use a bottle of mineral water, or you can fill an empty mineral water bottle with iron sand, which will have a better effect and can replace dumbbells.

1. Stand with your feet in a front-to-back position, with your left foot in front and your right foot in the back. Lean your upper body forward about 60 degrees, and hold a water bottle in your right hand perpendicular to the ground.

2. Lift your right hand up until your upper arm is parallel to the ground, support your left hand on top of your left thigh, perform 15 to 20 times, then switch sides, and perform three sets of cycles.