[4] After a brief stint at the Korsør Realskole, Sylow attended the Sorø Academy in 1877, where he helped to introduce football in 1878.

[4] Later that year, he graduated after taking a maths and science exam and was then employed by the Post and Telegraph Service.

As a result of this, Sylow was moved to Copenhagen and advanced to mailroom clerk in 1886, and became a post inspector in 1914.

[4] Shortly after he moved to Copenhagen in 1879, Sylow became associated with Kjøbenhavns Boldklub (KB), for whom he played several first-team matches in football, tennis, cricket, and was the captain of KB's cricket match team for many years.

[4] Over time he became heavily involved in the organizational work at the club, and in the mid-1880s, when KB took the initiative to look at the different forms of football and their laws, Sylow was one of its main promoters.