Most people think so.
So the truth is that it is not healthy.
Hard training sessions without proper guidance, rest days and so on can raise the stress hormone Cortisol to an unhealthy level.
And cortisol can create: weight gain, disrupted sleep, anxiety, depression, diabetes, and many other non-desirable conditions.
High-intensity exercises can also damage your joints, bones, create sagging skin, collagen loss.
As you can see, the list is long and not good.
Exercise needs to be prescribed by a training professional for a reason, and that is to protect your health.
So choose wisely and get a good trainer that understands all those points.
For more tips, download my books or exercise videos available on this website.
Is training very hard any good?