While there is no proof that ‘feeling the burn’ is beneficial in any way; there is no proof that it isn’t. Some like to think that it helps to build muscle faster, and burn fat faster, by releasing human growth hormone in greater doses once the burn is reached.
Whatever the belief, or the reason for wanting to feel the burn, what is true is that a muscle in which the burn is felt, is a heavily fatigued muscle which is burning because of the by product from a hard workout – known as lactic acid.
Seldom do I feel any real burn when I work out, because I tend to work to muscular failure with my working weight, and to feel the intensity of the burn, that wouldn’t be possible with a working weight – simply because when you fatigue at a certain weight, you can’t continue to lift – so you’ll need to take a different approach.
Once you’ve failed at your heavy working sets, if you want to go for the burn, I suggest you do a superset – a set performed immediately after – with lesser weight. It can be the same exercise, or a different one, so long as it hits the same muscles you are trying to get to burn.
So, once you’ve done your working sets, simply pick up the other lighter weights, and continue doing reps until the burn is achieved. Keep the reps high, and forget about sets; sets only give your muscles time to recover and at this point you’ll have already reached failure on your work sets; purely for the burn, all you need to know is continual work without let up, with light weight, will do it.
Personally, I think it’s not such a great idea to have your muscles flooded with lactic acid. I don’t think it’s necessary for muscle growth particularly, and I know for a fact that the more lactic acid (burn) that is accumulated, the longer it takes for the muscle soreness to go away and muscle repair to occur.