Variety, variety, variety.
If your goal is the be in the best physical shape you can, for the four big reasons (to be healthy, happy, hot, and fit, right?), then you've got to mix it up.
If your training routine keeps you in your comfort zone, change it fast, because you're losing ground.
Too many people find one exercise they like, whether running, spinning, swimming, weight lifting, pilates, yoga, or whatever, and then just "do" that all the time.
Without getting into loads of detail here (happy to if you'd like, just contact me), our bodies are amazing adaptability engines. We can very quickly adapt to something we do repetitively. This is a great benefit when learning something new, but it can work against us in fitness training because once we know how to do something and do that something (and only that something) repetitively, the fitness benefits diminish.
So cross training is clearly the answer, working the same and different body parts and functions in different ways, but many of us can still settle into a comfortable routine. And once again our body's amazing adaptability works against us.
So vary constantly. Variety, variety, variety.
