Option 2:

The twins have been training together since they have started playing hockey at a very young age. As such their training method is often not that different if not straight up identical. Of course they often copy one another when they see that something the other doing seems to be working well. As such Sonja has many of her training methods from Frøya. The main difference however is the way they warm up. After all Frøya is often found to be running on the treadmill which is something Sonja dislikes. Rather she would go on the stationary bike and use that for warm up. Once she is done warming up, she usually goes onto the ice and waits for her sister there, after all the pair still train together just like how they did all the way back when they started. While she waits, she usually do some slaloms both forward and backward to get into the rythm. Once Frøya arrives, the pair would usually hold a race to see which one of them is faster. Which of course allows them to see who needs to improve on what.