People in fitness like to hang onto a routine, having a routine in the first place feels comfortable. Having one is used mainly as a goal, if you’re a beginner or more advanced and it’s in your comfort zone and you’re use to it. The trap however is if you keep doing the same things over and over again eventually your progress begins to die out, results aren't coming in, you’re frustrated but also those who have a routine and stuck with it for a long period of time also eventually begin to only know that routine and don’t know how to change it.
I know what it’s like being burnt out, your body begins to take a toll on you and it’s time to make a change because your mind needs to be fresh, your body needs to re-energize and your exercise routine needs to bring out a bigger and exciting challenge. I was on a routine for about over a month doing mostly push-ups,squats and bridging using a deck of cards. What I've noticed lately is due to the excess work over 3-4 times a week is that I've gotten stronger and have more endurance but my shoulders and knees are breaking down on me and need to stop. Most likely I’ll change it to 1-2 times a week because with the cards you’re looking at a minimum of 388 squats and 238 push-ups (I make it 400/250 to make certain goals) and the bridging is hard enough as it is.
When your body begins to hurt more than it should from a routine, change your pace, use less volume or learn to exercise the joints, tendons and ligaments so you don’t get an injury. Find something fresh and fun to do because if you overload the body without using multi-directional exercises you can get hurt and you will be in pain. Also being burnt out means your mind isn't there anymore and if you keep it up, your mind just goes dead and you’re going through exercises like a zombie, it’s not fun and you’re getting the results you want and it’s bad for your health.
There are people (I happen to be one of them) who has a bit of ADD which means they can’t always pay attention to what they’re doing and they change things up frequently. This has been a bit of a habit for me because quite frankly I hate routines; aside from doing the deck of cards and some of the bridging for the last month and a half I’m constantly doing different exercises. This could also mean people like to go by feel, what they’re in the mood for. Some days they’ll do odd object lifting, other days gymnastics and even every once in a blue moon they’ll just hammer out whatever energy they have and try to go as far as they can go. Be careful how you do things but at the same time have fun and learn to use your imagination.
Here’s another reason to change things up; boredom. I've been there and seen plenty of guys in the gym do this and that’s being bored as hell with what you’re doing. If you’re not having fun and your routine is dull and what I like to use from the movie Your Highness is what Prince Thaddeus refers to as “It sounds tedious and boring” then you need some serious changes my friend (watch the movie and try to say it like he does, you’ll perk right up). You should never be bored with what you do. Want to know what boring is, look in the magazines and the routines they have, most of that shit is boring to do and who the hell can finish them in the amount of time it needs? Find a way to train that gives you freedom and challenging. Find what gives you a reason to train, make it interesting and use the power of being happy with what you do. An exercise program is supposed to make you feel good, not terrible and hurt; it gives you energy and happiness not dark and un-eventful.
The ultimate reason to change things up is to create a new challenge. If you can do a deck of cards doing push-ups and squats in full within a period of time after a while, it gets easy, how do you make it harder? Double the push-ups and/or squats and see how far you get. That’s an example, how about doing animal movements? Eventually you’ll get the exercise down and you need a change of pace, to make it more challenging, move slower to the point where you hold a position isometrically and then take a slow step.
Everything needs a challenge so we can learn to grow mindfully and get stronger physically because when you challenge yourself, you learn new things, how to make the exercise a bit more difficult or the tempo and timing of the workout. Maybe you’ll do a challenge once a week/month/year whatever but do it and find new ways to make it interesting and learn how to handle yourself in certain situations. Growth is a natural part of life so what makes exercise any differently? Get to it and change things up, you may find certain things more fun to do than others.