How much rest and recovery do I need after workout?

You are constantly balancing between the sympathetic and parasympathetic nervous systems. Recovery is actually a push-down wave-like factor, in which your body is actively recovering from stress (ex. higher pulse rate). If you keep your pulse rate high during the entire workout exercise, you're limiting your potential gains. By adding more recovery between the sets of exercise and the frequency through the workout, you can optimize your performance, your strength, and your endurance, not to mention your actual weight loss. I do recommend HIIT, whereby you apply high-intensity interval training.