Beat the Burn
Increase your lactate threshold.
Lactate Threshold (also known as Anaerobic Threshold).
Forms of exercise that rapidly utilise glucose and glycogen for fuel, such as HIIT or sprinting, accelerate the production of lactic acid in your body. The lactate in the lactic acid is used as additional fuel, whilst the hydrogen ion in the lactic acid, the part that makes it acidic, causes that burn sensation that fatigues your muscles. When lactic acid builds up in your muscles and blood causing you to fatigue, it's because the lactate can't be used as fuel as fast as it is being produced. When you stop for each short recovery period during HIIT, the rate of lactate used for energy quickly catches up with the rate of lactate production, clearing the lactic acid build up, stopping the burn, and allowing you to push as hard and fast as you can again. Repeatedly performing activity that brings your muscles to fatigue from lactic acid build up will gradually increase the rate at which your body can use lactate for energy, thereby increasing your lactate threshold, enabling you to push harder for longer in your workouts before the lactic acid build up occurs.
Steady state cardio, such as long slow running or cycling under 70% HRmax, also improves your lactate threshold and the rate at which lactate can be used for energy. Even though it utilises a lesser percentage of glucose and glycogen for fuel, the supply of lactate to the blood is still raised, steady, and prolonged. Lactate is produced less rapidly allowing it to be used as fast as it is produced (which is why you don't feel that burn in your muscles). This forces the aerobic mitochondrial enzymes in your body to adapt to be more efficient at utilising the continuous higher levels of lactate in the blood, raising your lactate threshold in the process.
So basically to best increase your lactate threshold you should do both sprint interval training or HIIT routines, such as The 4 Minute Max Outs, and longer sessions of steady state cardio such as jogging. As you increase your lactate threshold, you will still feel the burn and sudden fatigue that brings you to a halt, it's just that you will experience it at a higher intensity of exercise. This will allow improved performance in your workouts which will lead to better potential results and health gains.
To put this into a practical example, a 400m runner, without HIIT and steady state cardio incorporated into their training may only be able to sprint at high intensity for 200m before chronic fatigue sets in, forcing him to run at a much lower intensity for the duration if he wants to complete the race. The same 400m runner, with HIIT and longer distance steady state cardio incorporated into their training may eventually be able to build up their lactate threshold to be able to sprint at high intensity for the full 400m before chronic fatigue sets in, dramatically improving their sprint time. Longer distance runners will benefit from sprint interval training and HIIT too. Olympic Gold Medallist Seb Coe famously used to run back to back 200m sprints with a 30 second break in between during training for his longer distance 800m and 1500m main events. This is not dissimilar to 30 seconds on 30 seconds off HIIT.