Ernest Needham on training (1901)

Well-directed exercise is the chief factor in training for any 

sport. Here I might warn against a most common error. Too many youths and men play football to obtain exercise, but this is quite wrong: exercise should, nay, must precede match football, or harm from exposure and over-straining is bound to ensue. Still more, the untrained man blunders about the football field, throwing himself blindly into danger, and proving a frequent source of accident to himself and others. This is so well known to professional players that trainers take charge of first-class men at least a month before their first public appearance of the season. To get into condition at the beginning of the season is hard work, for while resting superfluous fat has accumulated, some muscles of locomotion have become more or less flabby, the circulatory system is torpid, and the chest muscles and organs of respiration are slow in their action. To counteract all this, we must at first have plenty of football practice to bring the muscles into obedience to the will, skipping, walking, and running to strengthen them, sprinting to cultivate speed, and three-quarter and mile runs to tone up heart and lungs. Indian clubs and dumbbells are occasionally used. These various exercises, used lightly at first, and gradually increased under experienced direction, will produce the necessary vigour and hardness, and bring the player into condition for match playing.
From  Association Football by Ernest Needham (1901)

The versatile Ernest Needham made 554 appearances for Sheffield United in an 18 year career (1891-1909) during which he played in a League Championship (1897-98) and 2 FA Cup winning sides (1899, 1902). 
He won 16 England caps.