I always create my own training schedules and usually I do not change intensity throughout the years, but sometimes it helps if you slightly increase the load during pre-season.
It is important to monitor the happiness of your players regarding their training schedules and tweak it accordingly. A heavy training schedule can have negative impact if your player is unhappy about it, while a light/medium one is more likely to have a better effect.
It is important to monitor the happiness of your players regarding their training schedules and tweak it accordingly. A heavy training schedule can have negative impact if your player is unhappy about it, while a light/medium one is more likely to have a better effect.

