I'm currently experiencing DOMS (Delayed-Onset Muscle Soreness) in my legs, so I thought it would be a good idea to talk a little bit about the difference between DOMS (which is essentially muscle soreness after a workout) and an injury.
Again, I am not an expert, but I have had experience dealing with sports-related injuries and I have also obviously experienced muscle soreness. To give a little bit of background before I go on, I was involved in five different sports/athletic teams during all five years of my high school experience. I participated in basketball, volleyball, track, cross-country, and soccer. And like many high school athletes, I had my share of injuries, which ranged from my jammed fingers, to my twisted knee, to my ankle sprains. And since high school I have remained active by running, doing HIIT, and lifting weights. Anyways, I hope that bit of information gives you an idea of where most my fitness experience comes from.
Okay, let's move on. Do be aware that it may be difficult to distinguish between DOMS and an injury. Most medical research out there says that DOMS lasts for 24-72 hours, and anything after may require attention, such as a strain, etc. Although that may be true for some people, that time frame is not accurate for all. There have been times after an intense workout where I experienced DOMS for 4-5 days, but that does not mean I injured myself. The rule I like to follow is to give it a week. If after a week it is still bothering you, then you might want to get it checked out. But of course, if the pain is really bad and it has only been a couple days, do what you need to do to give yourself the peace of mind that everything is all right.
NOTE: DOMS is not an excuse to not workout. In fact, some cardio may actually help with blood flow, which in turn, helps relieve some muscle soreness. A few other effective ways for relieving soreness is to stretch, use a foam roller, and/or get a massage. Some people do take tylenol or the like to help with the pain, but to be honest, it's really not necessary. But that's just my opinion.
Anyways, I hope that spiel gives you a better understanding of the difference between DOMS and injuries, and do let me know if you have any questions.
Until next time.