This was a tough one to tackle succinctly. The answer is very dependent on where you are with your health and fitness, and how you are feeling and progressing through your current routine. Generally, I do not think you need to change your workouts up very often if they are accomplishing your goal, especially if the program is put together with some thought and effort. I think most people search for novelty too often in their fitness routine and do not leave themselves enough time to adapt to the stimulus their current workouts are providing. Change takes time and sometimes we are our own worst enemy. There is a time and a place to change your workouts and exercise selections and I will do my best to lay them out briefly.
If your goals are to stay fit and healthy and you have found a set of exercises that help you do so, there is no need to change anything until you reach a plateau. Deciding to stick with your current plan would mean that you are progressing your workouts as you would like and feeling the positive impacts that they have on your life. You are feeling healthy, moving well, and progressing towards your goal.
Staying fit and healthy is a very vague goal and in order to have a goal like that it means you have already gotten there. This takes a lot of work and a well thought out fitness and nutrition regimen. Any effective program includes progressions to exercises via weight, reps, tempo, range of motion, and form. I do not recommend changing exercises until you have manipulated some of these variables in a progressive way. For example, instead of changing the chest exercise you do every few workouts, try to stick with one exercise for three months and progress every one to two weeks. Below would be one method:
1. Dumbbell bench press
a. Pick a weight that you can perform three sets of eight reps. This weight should be heavy enough that the eighth rep of the final set feels like it is your last. This is your baseline,
b. Move up to the next weight from your baseline weight above, usually five pounds for dumbbells. This is your current working weight.
c. Perform three sets of five to eight reps with 2 minutes between sets. You are likely not going to achieve eight reps on each set if you picked your weight correctly. If you fail to perform five reps on one of your sets, increase your rest times between sets from two to three minutes.
d. Each week you will work towards achieving eight reps with your working weight and when you do, you would progress the weight, reps, tempo, or range of motion and start again.
The above progression scheme can last you months if done well. Next time you are in search of a change because you are bored, instead progress your current exercise(s) like shown above and you may find you look forward to the challenge each week.
My hope with this is that you will give some thought to your current routine and decide whether or not you have given yourself a chance to make the change you want. Have you progressed your weights, range of motion, tempo, form, or reps? Or have you done the same weight and reps over and over again without any thought to these variables? If you are frustrated with how it’s going I highly recommend auditing your strategy so that you can make the most effective decision. There are always reasons to change what you are doing, but I would be willing to bet that the reason you are not progressing has very little to do with the exercises you have chosen and more to do with your patience and strategy.
Have a great rest of the weekend!
-Matt