Warholm and his coach Leif Olav Alnes were recently gracious enough to sit down with our intern Alex Geula at Warholm's training base, the IK Tjalve club in Oslo, right outside the famous Bislett Stadium, and give him great insight into their training which seems to be a) super intense b) super planned out to try to minimize the reisk of injury.
On the hard days, Karsten arrives at the facility at approximately 10 a.m. and does not leave until 7 p.m. He does not double like a distance runner, where there is a long break in the middle of two runs. Rather, he shows up and trains for the entirety of the day at the facility (with a break for lunch). There's obviously a balance in the hard and easy days in the training schedule. This long training day is completed so that Karsten only has to warm up once in the beginning of the day. If he were to complete two different sessions, he would need to warm up twice, and the warmup takes a very long time and is integral to injury prevention.
The hard days are described as "red" days, and Karsten often rips off his shirt in practice, which he did in Tokyo after his 45.94 WR in the Olympic final. While the world was shocked at the sight of the WR and of him ripping his shirt, Leif has seen it many times before and thought it was commonplace after such an unbelievably hard run.