To summarize, here are but a few of ways that you can cross train your muscles:

* Heavier Weights * Higher Number of Repetitions * Change Position of Your Body * Modify Speed of Exercise * Use Machines as well as Free Weights

Challenging Your Cardiovascular System

Just like muscular system, your body will find ways to adapt to cardiovascular training that you do, and before long you will stop seeing a high degree of results. Let's try to use some of same concepts that we applied to resistance training, and see if they also apply to cardiovascular training!

Heavier Weights

How can you make yourself heavier? Most people are trying to make themselves LIGHTER when they exercise! However, if you are able to find a safe way to increase total amount of weight that your body is moving during cardiovascular training, don't you think that activity would be more difficult, and force your body to adapt? Sure it would!

A common method that people use to do this is one that you should NOT do, and that is strap on wrist weights or ankle weights, or to carry dumbbells while you are doing cardio. Although this does increase total amount of weight being moved by your body, it also puts a stress on your joints that is not natural, and therefore, not a good idea. However, alternatives that DO work include putting on an adjustable weighted vest, or even just strapping on a backpack with some weights or books in it! The idea is to keep additional weight as close to your body as possible, away from easily damaged joints.

Higher Number of Repetitions

Although you don't normally count repetitions when you are doing cardio, you DO take a certain number of steps, have a certain number of revolutions per minute on elliptical or bike, or you take a certain number of steps on stair master. Do you think that increasing those numbers would help? You bet! Whether it be by staying on equipment for longer, or just working out harder to get a higher number of steps or revolutions in same amount of time, either way you have changed stimulus on your cardiovascular system (not to mention your legs!), and by reacting to that new stress, your cardiovascular system will burn more calories while adapting to new program.

Change Position of Your Body

You may be asking yourself at this point just how many positions can body be in when you are walking on treadmill? The answer is PLENTY! Changing incline of equipment is an obvious way to change position of your body, provided you continue to STAND UP STRAIGHT. If you hunch over, or grab machine for support, you are defeating purpose. What about leaning backwards or forwards when riding a bike, or peddling an elliptical? By changing angle at which your legs are pushing on machine, you are most certainly changing stimulus, forcing your body to adapt!

Modify Speed of Exercise

This one pretty much goes without saying! Go faster, and you'll burn more calories, and elicit a new adaptive response from your body. However, what about going slower? What if you are used to Cycling class where your instructor seems to be made of steel, and can spin his/her legs around 80,000 times a minute for 30 minutes straight? Can slowing down be as effective as that? Sure it can! Trying reaching down to tighten up resistance knob on that bike past your normal comfort level, and it's guaranteed that your body and your legs will have to find a new way to provide energy, even though you are actually going slower than you were a few minutes ago.

Use Machines as well as Free Weights

Other than what we discussed above with weight vests/backpacks vs. ankle/wrist weights, you really don't use free weights during cardio. However, you DO ride a treadmill or an exercise bike or a stair master on a regular basis, right? Trade those machines in for real thing! Go outside and go for a brisk walk or a jog. Use a REAL bike and get out for some fresh air and an invigorating ride around your area. Find a tall building in your area and walk up and down stairs. It's a safe bet that after a few flights you'll be wishing you were back on stair master with it's motorized movement assistance!

The examples above have been just a few ways that you can cross train your body. There are many different training protocols, and literally thousands of different exercises that human body is capable of. You should research as many different training protocols as possible, and even enlist aid of a personal trainer if you need help setting up a program for yourself, or to change program that you are already on. Remember, key is to make your body ADAPT to new stimulus as often as possible!

Now get out there and get some exercise!

Let us now sidestep over to weight room where dumbbells are kept, and once again get in start position for a standing bicep curl with dumbbells. Notice term "standing". You know, like you DIDN'T do all day at work, and hopefully also did not do in your car on way to gym. So before we even start exercise, we are using more muscles than we did on machine - namely leg muscles.

Now let's pick up a 10 lb dumbbell in each hand. We've just added 20 lbs to our body weight. What is keeping us from losing our center of balance and falling clean over? The abdominal muscles and muscles of lower back and spine. Now we are using our legs, our abs, and our back. Flex those elbows and start to raise dumbbells. Now our center of gravity has become a fluid state, and our legs, back, and abs all have to constantly compensate to maintain posture. Oh, and biceps are also in on action by this point, as are forearms, fingers, and shoulder girdle.

We now have dumbbells all way up and it's time to start lowering them again, via an eccentric contraction of biceps (also know as extending elbow). What muscle group controls extension of elbow? The triceps on back of arm.

Did you lose track yet? It's okay if you did because you have illustrated point:

Machine Bicep Curl: Uses biceps, forearms, and fingers

Cost: Thousands of dollars

Standing Dumbbell Bicep Curl: Uses biceps, forearms, fingers, legs, abs, back, triceps, and shoulders.

Cost: $40 for a good set of dumbbells that can be used for dozens of other exercises

In a nutshell, free weight exercises simply USE MORE MUSCLES than machines do, which make them more effective. Does that mean that machines are a complete waste? Absolutely not! In some circumstances it is BETTER to stabilize muscles being used in any given movement. However, those circumstances are exception, rather than rule.

So what do you do? Change up your routine, and incorporate free weights as well as machine exercises. However, keep machine work to a minimum - say 20% of your total time spent working with weights. Spend other 80% developing your stabilizer muscles, your sense of balance and coordination, and if nothing else - just standing up!

After all, you can go home and sit down on couch to enjoy your post-workout snack. The bicep machine already brought kids home from soccer practice, remember?