Do you feel that your stamina has improved?
The same is true of your stamina, every few weeks you should experience a noticeable improvement in your stamina, particularly if you are doing a circuit workout, adding in aerobics, or really doing nice, slow, controlled weight lifting sets. You should notice that you tire less easily walking up stairs or being out for a run. For example, shovelling snow or mowing the lawn should be less tiring than it used to be.
Is your weighing machine still showing the same result?
Even if you do not feel stronger or like you have more stamina, your weight machine should tell the real tale. Keep a log of how many reps and sets you do at what weight and watch as those numbers right. There is no arguing with such improvement.
Have you increased your volume of sets?
Maybe you are not looking to build your muscles up huge, but are more concerned with improving your stamina. In this case, you can note how many reps and sets you are doing and watch as those numbers increase.
Are there any changes in your body measurements?
Keeping track of your body measurements is one no nonsense way to get proof that your workout is making a difference. If you have not yet, measure yourself. Take your weight, measure the size of your waist, hips, chest, thighs and biceps. Then, every six to eight weeks take those measurements again and see which areas are getting tighter and leaner and which are getting bigger and meaner. You can also use the scale and the fit of your clothing to see how your body is changing.
Do you have physiological changes in your body?
While building muscles, feeling strong, and looking great are all wonderful things, being healthy is important too. One way to tell how well your workout is working in improving your health is to watch how your vital signs are changing. For example, get your cholesterol tested, take your blood pressure, check your blood sugar, and even watch things like allergy reactions, fatigue and headaches. Every few weeks take these measurements again (keep a log) and watch for trends. There is a good chance that you will see some really positive changes as those muscles grow.