Any workout is better than no workout, so take the information in this article with a grain of salt. However, if you have the option of not working out first thing in the morning, then by all means take it.
Now without going over a bunch of physiology (and circadian rhythm graphs), I can say that the best time to work out is a couple hours after breakfast.
In any case, here is why working out first thing in the morning is not good:
1. Your spinal discs are bigger than usual: Right when you wake up, you are the tallest you will be during the day. This happens because the discs in your lower back have a little extra liquid inside of them. If you do a lot of bending or strenuous exercise right when you wake up, you are more at risk for lower back injury.
You see, when your discs are topped off with liquid, they are less mobile. And less mobility translates into higher risk of injury.
One more thing, if you already have lower back pain, early morning exercise should be out of the question for you.
2. Your body is breaking down at a fast rate: When you wake up, your liver does not have any carbohydrates, you are dehydrated by a couple pounds, and you are burning through muscle tissue like a knife through butter so that your brain can survive on the broken down muscle. If you do not eat quickly to reverse this state, this break down process will keep on accelerating.
Even worse, if you begin exercising on an empty stomach, this negative cascade of events will be amplified even further.
3. Your hormonal profile remains disrupted for the entire day: And you can’t reverse this no matter how healthy you eat. You see, cortisol and insulin are the major players here. If you start exercising on empty, cortisol will keep on rising and your levels of insulin will be disrupted for the rest of the day.
And recall that you need optimal levels of insulin in order to burn the most arm fat.
4. Your joints aren’t smooth, slippery and lubricated: It takes time for synovial fluid (the oil of your joints) to increase in quantity and slipperiness. If you simply jump out of bed and start exercising, your joints aren’t at their best in terms of being able to accept stress. Over time, this can degenerate your joints.
So at the very least, have a robust warm-up period before early morning exercise. And if you already have noisy joints (i.e., cracks and pops), you absolutely have to follow this advice.
5. Your body temperature is low: Body temperature regulates alertness, force production, reaction speed, strength and all metabolic processes. And it takes time for your muscles and body to warm up first thing in the morning. So try to get your body very hot before exercising very hard.
Now if you absolutely have to work out first thing in the morning because of scheduling constraints, then by all means proceed-something is better than nothing. Just make sure you have the biggest liquid meal you can tolerate, and incorporate a robust warm-up period. At the very least, this approach will mitigate a lot of the negative side effects.
And try to take the necessary steps so that you aren’t forced to exercise so early!