Setting Yourself A Baseline
To get where you feel you need to go, you will have to find a starting point in the form of a baseline of health. You can do this by doing a few health checks on yourself before you get started. It is not essential, but highly recommended. Especially if you have not done any exercises in quite a while. You should not go into strenuous exercises without having an idea of your limit.
Check your resting heart rate
Know your resting heart rate before you get started. Checking you pulse should be pretty straight forward if you can locate your pulse. Areas to check are on your wrist, the side of your neck just beside your Adams apple, and just in front of your ear.
Check your Weight
Lets get on the scales and see what we weigh then. Do not be afraid to be honest with yourself, or to realise there is a possibility that your weight will go up before it comes down.
Check your Blood Pressure
Or Get your doctor to do it for you. There are a lot of machines that can do this for you these days, and they are not too expensive. It might be worth investing in one so you can monitor yourself anyway.
Check your Flexibility
How mobile and flexible are you anyway? Can you touch your toes, how comfortable are you twisting or reaching from side to side?
Check Your Stamina
Find a machine at the gym that will allow you to check your cardio. Some machines are a bike, treadmill, stair climber. Set yourself a distance and see how long it takes to complete it, or set your self a time and see what distance you can cover. There is no problem with starting slowly and making sure you are well within a reasonable time. When you have completed the test, check your pulse, and then check it every minute after to see how long it takes for you to get back down to your resting heart rate.