"Stimulatory effects" of marijuana

Are there any?
on drugs.gov it says that although users can develop a tolerance to THC, they can't develop a tolerance to the stimulatory effects of marijuana.

Weird... cause I hooked myself up to a heart rate monitor and took a huge fatty out of the bong, then watched as my heart rate fluctuated from 82-94 to 68-73... it reduced... and stopped the fluctutions... odd... isn't it suppose to increase?

when i closed my eyes and concentrated on figuring out wtf the high sensation was from the weed, my heat rate stayed a flat 70 for more than 5 minutes... didn't change at all, normally it changes per breath. whats with that?

Some weeds stim and some dont and it also depends on when it was harvested as to the exact effect that it gives you