Yes, you can multitask while using the subliminal programs, that includes working, exercising, playing video games or even while sleeping as long as you are using stereo speakers for the ultrasonic (remember to listen to the normal version for at least 4 hours a day with headphones or earphones) or listening to the masked version with the headphones or earphones. (it is difficult to keep the headphones or earphones on while sleeping, but you can use something SleepPhones, You can find more information on the product here.
But please be smart enough to know when not to use, for example in a situation where you have to give your full attention. It is like listening to music. You just need to be smart enough to know when you should not listen.
You can also take breaks while listening, you do not need to listen to the programs for 4 – 8 hours continuously. But try to listen to the programs for at least 30 minutes.