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.
âBecause the plank exercise requires minimal movement while contracting all layers of the abdominal fascia, it is an excellent way to strengthen the core, which, in turn, helps reduce low-back pain.â. 3. Flexibility. While building strength, planks also increase flexibility in your posterior muscle groups.