The continuous nature of physical fitness concept ?

physical fitness is something that requires regularity and determination. You cannot overlook this once you achieve your goal, rather you need to do it every day. Physical fitness is the sum of all the choices you make regarding your lifestyle. Things like, what you eat, the amount of time you work, exercise and other factors like stress, lack of sleep can affect your physical fitness.  

You need to constantly work on it in order to improve your physical fitness, as a result, it has a continuous nature

well, it depends. it is natural to not fall asleep before 11: 00 p.m. teens need about 8-10 hours of sleep each night to function best.

enjoy your day!

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.