I have mentioned avoiding training bias before but wanted to address the benefit of developing health and strength by appropriate training. Our bodies are excellent at adapting. We get better with practice; our muscles become more efficient, and we make hard tasks easier as our bodies adapt to the challenges.
If we spend all of our exercise time in one form of challenge, our body will develop in that direction. For instance, I work with people who are avid runners. Running is their outlet, their way to stay healthy and control stress; it gives them a sense of control over their world. There are many psychological as well as physical reasons that people run. The problem comes if that is the only thing you ever do for exercise because you are developing a training bias. You are moving in a single linear plane–forward. Your muscles develop toward that challenge to make it easy and more efficient. Your lungs and heart benefit from it, but eventually you start to plateau where your body is good at maintaining a certain level of health. For maximal burn of calories and fat as well as building muscle throughout the body, you need to challenge your body in new ways. I see chronic runners with muscle weaknesses, and it always surprises them because they consider themselves so active and healthy.
If you are not challenging the muscle, it is going to get weak. Running is not a whole body workout. It is a great aerobic workout and better than sitting around and not exercising, but it should not be your only form of exercise.
Cross training or performing different forms and areas of exercise in one workout is great for the body. Now I don’t mean the cross training you are thinking of where there are lots of heavy weights and you constantly pushing your body to its limits with excessive weight and repetitions. I mean the definition of cross training: training across forms.
One day you run, the next day you do plyometrics, the next day you bike, the next day you play your favorite sport for exercise, the next day you lift, and so on. Or simply perform a work out routine that challenges different body parts such as ladders or interval training. That is cross training–challenging your body with alternative forms of exercise. This will prevent plateau through adaption and also prevent training bias. You will be consistently challenging different muscles which will tell your body, “Hey, keep this strong because I use it, so I will need it.”
I could go on and on about the benefits of cross training, how you burn calories in less time, increase your heart rate sooner, prevent plateau in fat burn, etc. What I don’t recommend is that people perform circuit training or interval training with high intensity until they have ramped up to that level. I see many injuries come from people jumping into a video that demonstrates high intensity and they try too soon to mimic that level.
Whenever starting an exercise program, listen to your body. Be kind to your body; it is amazing, and if you treat it right it can change and do amazing things for you.