What Is Needed?
- several bottles, for instance, 4 x 2L Coca Cola (figure 1).
- a metal rod or a strong wooden stick (figure 1).
- 3m (9 feet) of rope (figure 1).
Good place to get them is a rubbish heap.
Fill in the bottles either with water (density 1kg/L) or sand (density 1.8kg/L). For the sand you may go to a nearby sandbox. Thus, with the water the total weight is 4x 2 x 1 ~ 8 kg. With the sand – 4x 2 x 1.8 ~ 15 kg:
Place the bottles together. Wrap them with the rope near necks (top figure below) and at the waists (bottom figure bellow).
Stick the rode in between the bottles.
Now you have a piece of equipment to work on your biceps, wrists, and knee joints.