Ready to look about twenty years younger? Then put on about twenty pounds of muscle. Seriously, every pound of muscle will take a year off of your bodily appearance and make you significantly more attractive. I have warned you that Females Value Your Appearance and so, very likely, the better you look, the more strongly she will be attracted to you.
Building muscle is one of the key aspects to this and it doesn't have to be complicated. Most of it is common sense: do a hard workout without overtraining; get plent of sleep and rest; get enough protein and so on. You don't have to spend hours and hours in the gym, nor do you have to push yourself so hard you can't move for the next week because you're so sore. Quite the opposite.
Here at Peak Testosterone we encourage, whenever possible, to work smarter and not harder. And your pre-workout diet is an excellent example of this rule: taking five to ten minutes to eat or drink appropriately before your workout can make a significant difference in your muscle gains.
CAUTION: Before I go on, though, almost all store wheys that I have seen are loaded with dangerous excitotoxins and I document that here in my link called No Whey! However, there is an alternative, undenatured or biologically active whey, which I document in my link called Yes Whey! if you want more information.
But the reason that pre-workout drinks do their wonders is simple: leucine. As you know, when you eat protein your body breaks down the protein into a number of different amino acids, but it is primarily one protein, leucine, that triggers your body's absorption of these amino acids into your muscle tissue.  Some of you have read online or in bodybuilding mags the importance of protein to bodybuilding. Well, it really all boils down to this one key amino: leucine. And, for all you middle aged and beyond guys, one animal study shows that adding leucine to the diet actually reversed the age-related decline in protein synthesis! 
Numerous other studies have shown similarly remarkable results. There are many common ways guys ingest leucine, such as through direct amino acid supplementation, protein powder, egg whites and so on. More often than not, they are not even aware that their primary goal is leucine, but that is precisely how they are receiving their muscle-building benefits.
One of the most intriguing ways to your leucine is through whey. Whey is a dairy product and so one has to be careful regarding food allergies and not getting too much calcium is a risk factor for prostate cancer. However, one serving per day with no food allergies has some distinct advantages according to the studies. Many studies have shown that whey is a potent immune system builder and also dampens post-meal glucose and insulin response.  We also document, in our thread on Easy Weight Loss, how whey can help you lose weight as well. In other words, whey appears to have many health benefits besides building muscle.
But the real key isn't so much what protein you eat but rather as to when you eat it. It turns out that it is critical that you consume protein in a pre-workout meal about an hour before your weight or strength training. One study examined protein uptake into muscle when protein was consumed pre-workout versus post-workout.  Their interesting discovery was that amino uptake into muscle was stronger with a pre-workout meal, probably because the aminos were already digested and in the blood stream during the workout.
Personally, I eat egg whites since I believe that I am a little lactose intolerant and have a mild dairy allergy. The key, though, is to get that protein in before lifting and then consume some protein as well afterwards. For more tips, see my link on Muscle Building 101.
NOTE: As a side note, there is one study that shows fasting can actually stimulate an anabolic state.  I don't recommend that - just an interesting footnote. In addition, one should be very cautious about a Low Carb Diet as at least one study has shown greatly reduced muscle protein synthesis and recovery parameters on this type of diet. 
1) The Journal of Physiology, Jul 1 2007, 582:813-823. "Nutrient signalling in the regulation of human muscle protein synthesis"
2) The Journal of Physiology, Dec 1 2005, 569:489-499, "A leucine-supplemented diet restores the defective postprandial inhibition of proteasome-dependent proteolysis in aged rat skeletal muscle"
3) FASEB Journal, "The Effect of Whey Protein on Post-Meal Blood Glucose and Insulin"
4) Am J Physiol Endocrinol Metab, Aug2001, 281(2):E197-E206, August 2001, "Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise"
5) European Journal of Applied Physiology, Mar 2010, 108(4):791-800, "Increased p70s6k phosphorylation during intake of a protein carbohydrate drink following resistance exercise in the fasted state"
6) Journal of Exercise Physiology, 2009, 12(6): 33-39, "Dietary Carbohydrate and Protein Manipulation and Exercise Recovery in Novice Weight-Lifters"