Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
NumPad1: Infinite Health
NumPad2: Infinite Stamina
NumPad3: No Hunger
NumPad4: No Thirst
Press CTRL+H at any time to temporarily mute all hotkeys.
Press again to unmute. You can change this hotkey in the trainer settings.
You can also mute specific hotkeys by changing the hotkey you want to mute to 'NONE'.