Delayed onset muscle soreness (DOMS) is no fun. It is thought to be caused by eccentric (lengthening) exercise, which causes small-scale damage (microtrauma) to the muscle fibers.
Some things you can do that may reduce DOMS are:
1.) Make sure you are eating enough. Diet culture might have you thinking you need to restrict your calories. But if you’re really sore 2-3 days after a workout, there is a good possibility you might not have eaten enough. Seriously.
2.) Get enough sleep. Our bodies repair and heal, both physically and mentally, while we sleep. If we are sleep deprived, our fatigued muscles take longer to heal. Everyone is different, but 7-9 hours of sleep is generally the right amount of sleep for us humans.
3.) Use your sore muscles. If your legs are really sore after leg day, and it’s been 2, 3, or even 4 days since blitzing your quads and hammies, go for a walk, a bike ride, or stretch. You’ll hate it at first, and maybe still after a little while, but when you finish, your soreness will be a little less and your flexibility a little more.
4.) Take an epsom salt bath. Epsom salt + hot water = heaven on sore, achy muscles. Not much else to say about this one.
5.) Wait it out. If you’ve done numbers 1, 2, 3, and 4 above and you’re still as sore as you’ve ever been, you might have just worked out too hard. Next workout, lower the amount of weight you use so that you can do reps in the 12-15 range, and leave a little in the tank so that you’re not stumbling out of the gym and wincing through another 3-4 days of intense soreness.