Build lean muscle

You will probably not be surprised to learn that the answer to the question "how do you build lean muscle" is proper eating and exercising! 

The best overall approach involves three components: 

1. Eating correctly, feeding frequency, sufficient protein
2. Strength training
3. Cardio exercise

I'll make a few suggestions about each and then suggest some free programs. 

(1) Here's how to cut through all the confusion about eating well. Eat a smaller meal about every three waking hours (5 or 6 meals per day). It's critical never to skip a meal, and to obtain sufficient protein at each meal. 'Sufficient' means at least 15 grams of protein per feeding if you are female and 20 grams of protein per feeding if you are male. Remember to drink plenty of fresh water. I suggest 3 quarts daily and adjusting your intake from there. Your protein should come from natural sources such as meats, eggs, and fresh caught (not farmed) fish. Don't consume dairy products (many people have an intolerance without being aware of it). 

Avoid or strictly limit refined processed carbohydrates (apart from the occasional treat). Refined processed carbohydrates are a major cause of unwanted weight gain, obesity, insulin resistance, hypertension, heart disease, and many other diet related diseases. Replace those foods with 'fat burning' foods and take advantage of the excellent fat-burning thermic effect of these foods. If you are unsure what these foods are, you will fine a list of refined processed carbohydrates and a list of fat burning foods, and more about the thermic effect of foods, further down this page, under Sources and Related Links. Eating that way will boost your metabolism. Increasing your metabolic rate is the key to achieving and sustaining a low percentage of body fat. 

(2) Proper strength training will build lean muscle, which is your METABOLIC FURNACE that will burn additional calories 24 HOURS A Day. Do a whole body routine. Concentrate on the basic, compound exercises, which are full squats, deadlifts, presses, rows, dips, and chins. Learn proper exercise technique and use it on every rep. You will find free routines for beginners and intermediates, as well as lots of other relevant information such as safety and warm-up tips, further down this page listed under Sources and Related Links. Once you are able to train intensely, you'll experience DOMS. In order to ensure systemic recovery, wait 24 or 48 hours after all DOMS has disappeared before training again. Remember: you do not grow in the gym. What you do in the gym should stimulate growth during the recovery period. Exercise is like medicine: too little is ineffective and too much is counter-productive. Get plenty of sleep. In practice, this probably means that you'll be doing a strength training session of about 45 minutes once every 4 or 5 afternoons. 

(3) Cardio will also increase the amount of calories your body uses during and immediately after exercise. Choose some kind of mild cardio exercise that you hate the least and do it six days a week. I suggest brisk walking. Brisk walking is sustainable long term. For a choice of free cardio plans (one easier plan, one harder plan, one intense plan, see the relevant page links, further down this page, listed under Sources and Related Links. 

'Brisk' means walking at a 4 mph pace. Slowly work up to that pace and then slowly increase your distance. (Listening to an audio program while walking, can make it much more enjoyable.) If you simply want to maintain your present percentage of body fat, start by walking two miles daily. That should do it. If you want to use mild cardio to lose body fat, follow the free cardio walking plans listed under Sources and Related Links. 

So, in summary, to build lean muscle you need to eat properly, engage in cardio exercise, and do strength/weight training one or two afternoons per week. You can use that program from now until your dotage. If you adopt it and make it habitual, you are going to build lean muscle. You will love the way you feel and look. (Before changing your exercise habits you may wish to get the blessing of your physician.) 

All the above will enable you to build lean muscle.