1. Classic Training: Classic training is a simple one and the easiest to do well in. It takes -1 DP for 2 trainings and grants +1 Attack for each training. It takes 4 trainings to get a "Megahit." which will increase your megahit's power during real battles. Obviously, all you have to do to do well at this training is to press the button when it's at 100%
2. Pendulum Training: Pendulum training is where it starts to get a bit more complicated, but it's not as hard as it seems. With pendulum training, you must shake your phone a certain amount of times to get a "megahit." This shaking amount depends on each individual Digimon, but should always be between 2-9 shakes.
This can be better than classic training because you can essentially cut your DP usage in half and it also helps practice for online battles which are strictly pendulum based.
When you shake the phone, you will hear a clicking sound. That is your count for shake amount. So you must listen in closely to know how many times you've shake the phone. Be careful to listen because you may accidentally shake it twice and not even realized it. It takes a little bit of practice, but it really isn't that difficult.
Read more: http://digimonunlimited.proboards.com/thread/39#ixzz2leIFh2yK