Krein trains twice a week and supplements this with three additional hitting sessions, including two high-intensity match practices. He also runs three times a week, combining interval, endurance, and recovery runs, to stay in top physical shape. Competing in both spring and fall league matches, as well as as many tournaments as possible, he’s focused on steady progress and consistent competition experience.

Over the past 1.5 year, Krein has made significant improvements, moving from a 7.3 to a 4.6 KNLTB rating. His strong serve and forehand are key weapons that allow him to take control of points, while his speed and fitness make him tough to beat in long rallies. His mental strength was on full display last summer, when he captured four tournament titles, including a win after saving two match points.

Some of his best results based on UTR are:
– 6-2 6-1 win over Marijn Mulder (UTR 7.74)
– 4-6 7-6 2-6 loss to Ruben Nijboer (UTR 8.45)
– 5-7 7-6 10-7 win over Sebastiaan Cares (UTR 7.62)

Academically, Krein is interested in fields such as Criminology, Business, Law, and International Security Policy, and is exploring which direction best fits his ambitions both on and off the court.