If you start to feel tired in the middle of a workout, it is because your body has run out of oxygen, which begins to cause an accumulation of lactic acid inNutralite Ketomuscle tissues. That feeling of tiredness makes you want to give up, but introducing yourself to your diet could send more oxygen to the muscles and decrease the accumulation of lactic acid to give you more energy when lifting weights. Increased oxygen in muscle tissues decreases fatigue , so you can train longer and harder.