The monthly challenge gives you a specific goal or target to aim at over a month. Over this 4 weeks, you can set a benchmark, work hard and see real improvement at the end.
How will this challenge help you?
This helps in 2 ways. First, it is a progressive physical challenge, so you will have to work gradually harder over the month.
Secondly, it is a behavioural challenge, to help teach you how you can improve yourself independent of others.