Your age is probably the biggest factor when it comes to being able to bulk or add lean tissue effectively.
Under 30 Years Old
Young dudes tend to be bathing in testosterone and growth hormone. They have good insulin sensitivity and they're working with efficient metabolisms. These are the prime years for all-out bulking cycles, and it's when you'll get the most out of them from a growth standpoint. I'm talking about dudes past puberty and younger than 30.
Over 30 Years Old
After 30, the loss of fast twitch muscle fibers, the slowing of metabolism, and a shallower and less responsive hormonal pool all become factors for muscle building.
This doesn't mean a noob in his 30's isn't capable of making some awesome muscle mass gains. He can. It just means he's not working with his most optimal physiological environment compared to the late teens and early 20's.
From a nutritional standpoint, your actual age matters significantly. Due to being less insulin sensitive as you age, and needing a greater supply of leucine to maximize muscle protein synthesis, you'll need to manipulate your carbohydrate and protein intake to take these variables into account.
Lifters under 40, regardless of whether they're bulking or cutting, will get by just fine on a protein intake of 0.8 to 1.0 gram per pound of bodyweight. Someone in their 40's will need a greater intake of protein to fully maximize muscle protein synthesize (while paying special attention to leucine intake).
Over 40 you're going to want to eat protein at a rate of around 1.25 to 1.5 grams per pound of bodyweight, whether you're trying to gain muscle or lose fat.
Carb intake should be comparatively different as well. A young guy swimming in hormonal bliss that's relatively lean might need to take in as much as 3.5 grams of carbs per pound of bodyweight in order to maximize growth.
A 45 year old guy who's similarly lean probably won't be able to do that without gaining excessive fat. For a guy in his 40's, carb intake to the tune of 1.5 to 2 grams per pound of bodyweight will be in the ballpark for mass gaining.
Fat intake during a mass cycle for a younger guy should be on the lower side with carbs being the focus. For the older guy, a slightly higher fat intake, lower carb intake, and high protein intake will serve him best.
During a smart bulking or cutting cycle, everyone needs to create a starting point at maintenance calories, then adjust protein, carbs, and fats from there. Maintenance for most people is going to fall within the spectrum of bodyweight x 13-15 for caloric intake.
For mass gains, add about 10% to your maintenance intake. Yes, you'll have to log everything, track your weight and body comp, and adjust as needed to fine-tune these starting numbers. That 10% increase in calories comes from carbs, fats, or a combination of both, as long as the requirements for protein are being met.
For a fat loss cycle, simply subtract 10% from maintenance and reduce carbs, fats, or both based on preference. Protein really shouldn't change very much, if at all.
Age and Training
Younger guys with limited training experience will be able to get away with more workouts in a week and still recover. That's mostly because they aren't very strong and haven't cultivated the ability to train with an exceptional amount of effort. Due to their more efficient physiological environment and lack of existential life stress, young dudes can often train more and recover just fine.
But this more or less applies to noobs at any age. If you're still novice to intermediate, you'll probably be able to get away with training more often each week than an advanced guy who's capable of slinging some heavy iron.
- For the young lads, 5-6 training sessions a week will probably be doable.
- With guys over 30, four to five times a week might work best.
- For those over 40, three to four times a week is often ideal.