The word "challenge" can seem scary, since you know what follows probably won't be easy. However, without challenges we cannot change. This applies not only to fitness, but life in general. Challenges are the catalyst for growth, and instead of letting it be a deterrent, we should try to embrace the hurdles our journeys come across.
"We must accept life for what it is- a challenge to our quality without which we should never know of what stuff we are made, or grow to our full stature." -Robert Louis Stevenson