There are some people who lead relatively sedentary lifestyles. They are less active by nature. This does not mean that they are unhealthy, however, as even a sedentary person can get in some form of exercise (and people operate at different energy levels).
On the other hand, there are those individuals who are active by nature. They work out, spend time outdoors, or otherwise do something physically active daily. They also push themselves to challenge their physical limits. Inevitably, these results in some form of exhaustion, strain, or even injury. The toughest part? Letting themselves heal.
Healing Requires Rest
Now, we've all been there. I can not tell you how many times I've been injured in training or competition, and it's very difficult to just take it easy after the fact (except it hurts so much to move, anyway). I've heard countless stories of, “I think I started running on my sprained ankle too soon” or, “I know I have a dropped muscle, but I just had to go surfing last weekend.”
In order to heal properly, you need to rest, but this does not mean zero physical activity. Go for a walk instead of a run. Lift lighter weights or stick to body weight exercises. Do some light to moderate stretching, or yoga. There are a great many things you can do without training an injury.
Healing is Strength
When we push ourselves to our physical limits, or even do movements we are not used to doing, we damage our muscles. Now, do not freak out. Your body does not break so easily. That damage is what prompts our body to become stronger.
Muscle cells respond to damage by basically growing new muscle cells, but not exactly the same as before. Since the muscle cells were not strong enough to handle the activity or movement without damage before, they repair stronger, with more muscle cells (or more effective contracting of muscle cells).
You know that time you were sore after a weightlifting session? That soreness is a sign of training muscles, and with some exceptions, a sign of those muscles getting stronger. After some rest, what do you notice after your next workout? You feel stronger, do not you? Your stamina may even be better. Giving your body time to repair will make you stronger in the long run.
Are you Hurt or Injured?
A simple question dragged from a football movie … in fact, this may seem a silly question, but there is a pretty big difference. Building back up after soreness or mild strain is different from coming back after an outright injury. If you're sore, you can usually take it easy for a day or two, or just tone down the activity. If you're injured, it will take a lot more in the way of rest to get you back to fighting form (without re-injuring yourself).
As with most (if not all) of my other discussions, I would like to point out that your body is designed to heal itself, whether from illness or injury. When a particular movement hurts, it's your body's way of telling you not to do that, at least for a while. Our difficulty is recognizing what our body is trying to tell us. Sometimes, we just need a little help.
Injury can result in qi blockages and / or imbalances, which can result in pain or impaired movement. Pushing through does not mitigate the imbalance. Consequently, it takes much longer to heal. Rest. Most of you probably know the phrase, “Build it, and they will come.” Rest, and you will heal.