What triggers the "Juiced" effect?

Just started playing MW3 multiplayer, and I noticed that sometimes I received a buff called Juiced upon respawn. This buff increased my speed momentarily (presumably so I could get back in the fight), but it left me wondering: what caused it?

Is it something I can trigger intentionally? Is it random?

Juiced is a Deathstreak Reward received when you've died four times in a row without a kill, (3 times with Hardline Pro). You run faster than if you'd just used Lightweight, and it occurs on every respawn until you kill someone.

http://callofduty.wikia.com/wiki/Deathstreak

http://callofduty.wikia.com/wiki/Juiced

Juiced kicks in after a sequence of deaths and continues to have effect until the next time you get a kill.

It kicks in after 4 deaths, or 3 if using Hardline Pro.