There are two types of people in the fitness world; those who love the burn and those who dread it. Let's break down what "the burn" is. While exercising, your body creates lactic acid.... this happens during anaerobic respiration. During anaerobic respiration, your body gives off an H+ ion, and without oxygen to take this, your body produces lactate. This lactate is what causes the burn in your muscles while you're exercising. Many people think the lactic acid builds up and that's why your muscles continue to hurt and be sore in the following hours. NOPE. Your body gets rid of lactic acid quickly and efficiently once you stop exercising. The burn you feel the following day or so is from DOMS... Delayed Onset Muscle Soreness. This is most likely caused by microscopic tears in your muscles healing, which is also how your muscles hypertrophy. I say most likely because scientists have a few theories, but that is the most backed explanation for why you cringe when you sit down after leg day.
Hate the burn? DOMS isn't a sign of an efficient workout... you don't have to feel sore and broken the following days to have gotten a good workout. Love the burn? It's not healthy to feel broken down every day. The body needs time to recover fully, so make sure to alternate body parts and intensity accordingly. If it's sore, work something else. If everything is sore, take a rest day. You don't want to give yourself an overuse injury that can set you back. As for the lactic acid, the lactate threshold can be increased so that you don't feel it as soon into your workout but takes a lot of anaerobic work. What is anaerobic respiration exactly? It's any exercise that doesn't utilize oxygen... so a sprint or a one rep max. Doing sprint intervals will help to increase your lactate threshold but you'll be feeling the burn until you build it up! Bicarbonate buffering has also been shown to help decrease lactate build up.
If you really hate the burn, avoid it. Interval training can help decrease the amount of lactate you build up but it also travels in the blood so when you start to feel the burn after some squats you can switch to shoulder presses but you'll start to feel the burn sooner as your workout continues. The burn is fairly important... you want to get your heart rate up to maximize calorie burn but something is always better than nothing. So don't think that taking it slow and easy to start isn't worth the effort. Eventually your body will adapt, you won't get as sore, and it will get easier. I promise! If the soreness is going to turn you off from exercising, I would rather see you do less than do nothing. Push your boundaries when YOU are ready.
If you're like me, and you love the burn, just be careful not to overdo it. Listen to your body. If I'm sore but still want to get a workout in, I'll do low intensity cardio. Always make sure to stretch after every workout and especially a little extra if you're feeling sore. Ibuprofen and ice if you really need it, but DOMS should subside within 24-36 hours :)
Understanding the burn sometimes helps you appreciate it!
LOVE THE BURN!