The Meaning of Real Strength By John Steele

     My favourite strongman of all time, including fictional characters, is Arthur Saxon (1878-1921), the first man to press with one arm over 300 pounds of iron over his head. Most men today would be struggling to press a quarter of that with two arms. Anyway, although strong in muscles Saxon had this to say about different types of strength, which is quoted here, to give you, hopefully … strength:

“The following is my diagnosis of real strength: ‘Genuine strength should include not only momentary strength, but also the far more valuable kind of strength known as strength of endurance. This means the ability, if you are a cyclist, to jump on your machine and ride 100 miles at any time without undue fatigue; if a wrestler, to wrestle a hard bout for half an hour with a good man without a rest, yet without becoming exhausted and reaching the limit of your strength. Apart from sports, enduring strength means that the business man shall stand without a break-down, business cares and worries, that he shall be capable when necessary, of working morning, afternoon and night with unflagging energy, holding tightly in his grasp the reins of business, retaining all the while a clear mind and untiring energy, both of body and brain.

The man who can miss a nights rest or miss a meal without showing any ill effects or without losing any physical power, is better entitled to be considered a strong man that the man who is only apparently strong, being possesses of momentary strength which is, after all, a muscle test pure and simple." “Where a man raises once only a heavy weight all that he proves himself to possess is muscular control and great contractile power, but this does not guarantee sound internal organs nor does it prove that a man would come out well in an endurance test.”

     In short, strength is also making it to the end of the racecourse of life, perhaps the only real strength worth having.
  https://www.youtube.com/watch?v=sciLYTtRL-I