Physical strength has limitation but that limitation can be outdone by the mind.
Fear of something, fear of the unknown, fear of the result, fear of failure and various kinds of fear are the barriers for you to go forward to reach your goal, to work the things previously a daily routine due to ailments, to love, to lead, to try what you wish to achieve, to go up higher places, etc.
Any fear is in the mind only. You have to condition your brain that what you want, you can do it, that you have the power to make it.
Be brave to execute what your inner self urged you to perform, just concentrate on what you are doing and surely you will be a winner.