Always sticking to the same familiar training ,with the same weights and repetitions you feel sure and comfortable about is an inefficient way to train. Getting out of this comfort-zone of yours and introduce all kinds of variations is the key to change your body to a better version. You can vary in the way of execution, the exercise itself, the duration of work/rest, the intensity of your workout and many other ways to always surprise your body.
Bootcamp, Tabata, Crossfit, HIIT, Calestanics and Yoga all are training-methods, which are fun to do and bring common fitness to a next level.
Of all these disciplines I use the best elements and offer these during my training-hours in a way they are fun and challenging to do. I prefer bodyweight exercises with functional movement which can and will be increased with more weights or resistance to always go over your (mental) borders.
This way, you’ll not only get stronger; also your coordination, agility and stamina will improve. Excessive bodyweight will vaporize, your sleep will improve and you will experience more energy than ever before!