Daily backpacker budget: $20 ~ $35. Bolivia is the ultimate cheapie of South America. Things may be very basic here as itâs a dirt poor country but your dollars sure go a long way. It is the cheapest country for accommodation and the cheapest for food and drink as well.
The plank strengthens the abdominals, back, and shoulders. Muscles involved in the front plank include: 1  Primary muscles: erector spinae, rectus abdominis (abs), and transverse abdominus.he plank strengthens the abdominals, back, and shoulders. Muscles involved in the front plank include: 1  Primary muscles: erector spinae, rectus abdominis (abs), and transverse abdominus.
Each variation targets and challenges different muscles, but when done correctly planks can build strength in your abdominal muscles, upper and lower back, shoulders, chest, quads and glutes. See Also: How to Do a PlankPhoto Credit: ShutterstockClick Here to See More Ways to Get Strong Without Lifting Weights.