Three Requirements for Muscle Growth

There are three key requirements for muscle growth to occur. To ensure muscle growth you need an appropriate training stimulus, proper diet with adequate protein and of course plenty of recovery. A fourth factor, not discussed here, is the important role that genetics play. We all know people who train hard, eat well and get plenty of sleep. They typically get stronger but don’t really pack on lean muscle. There are many variables that can effect (1) how much and (2) how quickly your body adds lean muscle. This ultimately depends on age, gender, genetic and hormonal factors. There is a saying out there when talking about the part genetics play: “If you want an Olympic athlete then you need Olympic parents.”

Appropriate Training Stimulus for Muscle Growth?

How do you stimulate muscle growth? When a persons muscles are challenged they adapt and change over time. Changes are dependent on the type of activity and muscle fiber types used, the load exerted on the muscle, and the velocity and duration of the contraction. (Marieb, 2004) The point is to push through all the hard workouts, because muscular growth or hypertrophy can only be accomplished through these adaptations and changes. “It takes about 16 workouts to have a noticeable ‘superficial’ effect. There is simply no other recipe to do this in a healthy, orderly, and long-lasting manner.” Try using the Jefit, a workout planner & tracker app to record all your workouts.

Is the Current RDA for Protein Enough?

This is a tough area for a lot of people. Their eating habits are just not where they need to be. In addition to eating well-balanced, highly nutritious meals, protein intake needs to be sufficient. If not, muscle growth to say the least, will be difficult if not impossible. The scientific research has shown different results over the years in terms of protein needs.

The question we should ask ourselves is – do we follow the suggested RDA of 0.8 grams/kg/day for protein intake or is it more in line with 1-2 gram/kg/day? The answer may depend partly on the volume of daily exercise you’re doing, if you’re a strength or an endurance athlete, and your age.

Adequate Nutritional Intake (Especially Protein)

A classic study was done in 1988 at the USDA Human Nutrition Research Center on Aging at Tufts University. I was actually one of the test subjects in that study and also later worked there. The team headed by Meredith and colleagues, looked at the protein needs of 12 subjects. Six were young (26.8 +/- 1.2 yr) and six were middle-aged (52.0 +/- 1.9 yr) endurance-trained men. All subjects consumed either 0.6, 0.9, or 1.2 grams/kg/day of high-quality protein over three separate 10-day periods. They did this while maintaining their training and a constant body weight. The results of the study estimated that protein requirement was 0.94 +/- 0.05 grams/kg/day for the 12 men. The data from the study showed endurance exercise was associated with a specific dietary protein requirement. These needs were actually greater than the current Recommended Dietary Allowance of 0.8 g/kg/day.

Since then, there have been several studies on individuals who engaged in regular aerobic exercise. The exercise, more vigorous in nature, demonstrated a higher protein need more in line with 1.1 to 1.4 grams/kg/day. This by the way is about 38%-75% above the current RDA range. There is good evidence that the current recommended protein intake may actually limit muscle growth. This was seen in a study published in the Journal Applied Physiology. Some researcher’s report an optimal intake more in line with a protein range of 1.5 to 1.8 grams/kg/day which is 88% to 125% above the suggested RDA. The best way to make this happen is by ingesting 25-30 grams/protein with each meal and of course supplement with a post recovery protein drink.

Optimal Recovery (Sleep)

You can have the two other two boxes checked but if sleep is not happening, muscle growth will not occur. As a persons training intensity increases, more recovery and sleep is needed. According to the National Sleep Foundation (NSF), we need 7-9 hours of uninterrupted sleep each night. Are you getting that? When this happens on a regular basis for you, you can check that third box. Here are their guidelines for recommended amounts of sleep by the NSF.

  • School age children (6-13 yrs. old): Sleep range widened by one hour to 9-11 hours
  • Teenagers (14-17): Sleep range widened by one hour to 8-10 hours
  • Younger adults (18-25): Sleep range is 7-9 hours (new age category)
  • Adults (26-64): Sleep range did not change and remains 7-9 hours
  • Older adults (65+): Sleep range is 7-8 hours (new age category) 

Key Take Aways

Increasing strength and building muscle can seem like a full-time job at times. You will need all the help you can get to make this happen, especially on both fronts. By checking all three boxes (training/nutrition/sleep), your odds of finally adding lean muscle will improve greatly. Be Well and Stay Strong!