So i have herd that speed is affected by your Momentum in the game... This will take a little explaining so bear with me.
The ways that you can get more speed which in result will help your team score goals...
*Scoring goals will help your players get speed
*Less turnovers will result in more speed
*Try to minimize your offsides and icing as that slows down your players
* As in real life, If you come out of the gate with too much agression and always using speed burst then you will become tired... Its not an arcade game where you can speed burst the whole game... Use it when you need it!!
* Last way of getting speed is by winning fights and giving crunching hits to the other team.. it will slow them down and give your team speed!!
Hope this helped! Please leave some XP If it did 🙂