How many evs do seminars give in sword/shield?

I recently sent my Volcarona to a sp. atk seminar for a whole day, and it gained 252 evs. A few days ago, I sent it to a speed seminar for the same amount of time, and it gained 96 evs. Why is this happening? Does it have something to do with my Volcarona’s nature (+sp. atk, - def, but I’m gonna change it soon)?

Pleaselog inorregisterto add a comment.

“Seminars” reward 4 EVs for every hour the Pokemon is assigned, or 96 EVs for 24 hours.

So the EV’s you got for Speed was correct. But,

Notably, the amount of EVs earned from these sessions is affected by whether the Pokemon has a Power Item equipped, or is infected with Pokerus. To use the Attack Seminar as an example:

1 Day Attack Seminar with Pokerus: +128 Attack EVs1 Day Attack Seminar with Power Bracer: +288 Attack EVs (Maxed Out)1 Day Attack Seminar with Pokerus AND Power Bracer: +432 Attack EVs (Maxed Out)

So, as your Volcarona was holding a Power Lens, the amount of SpA EV’s it was supposed to receive became 288, but as 252 is the Maximum EV’s it can have in a stat, it received 252 EV’s.

Source

Hope I Helped