Protein and Strength Training—Two Important Components for Healthy Aging

Story at-a-glance -

  • According to recent research, current dietary guidelines on protein intake may be too low for health, particularly if you’re over 50
  • Protein is essential for optimal muscle growth and maintenance—especially for seniors—but there are drawbacks to eating too much protein as well
  • Protein alone is not a magic solution against age-related muscle loss. You still need strength training to actually build muscle, and if you have cancer, protein can stimulate the mTOR pathway, which increases cancer growth

By Dr. Mercola

As you age, it becomes harder to maintain muscle strength and bone health. Muscles tend to reduce in size unless you consistently exercise, which decreases strength and increases the likelihood of falls and fractures.

Diet and exercise are two important components to consider if you want to live a long and healthy life.

Protein is essential for proper muscle growth and maintenance—especially for seniors, as your body becomes increasingly less able to use dietary protein for building muscle—but I would recommend caution.

There are drawbacks to eating too much protein. Balance is key, as is making sure you’re getting high-quality protein. As for exercise, strength training can help counteract age-related muscle wasting, and help strengthen your bones as well.

Moreover, upping the intensity of your resistance training can achieve a number of beneficial changes on the molecular, enzymatic, hormonal, and chemical level in your body, which will help slow down many of the diseases caused by a sedentary lifestyle.

Should Seniors Double Their Protein Intake?

According to recent research, current dietary guidelines on protein intake may be too low for health, particularly if you’re over 50. As noted in Science Daily:1

“Current US recommendations for daily dietary protein intake are 0.8 grams/kilogram of body weight (roughly 62 g of protein per day for a 170-pound person).

Previous research has shown that older adults need a protein intake of at least 0.40 g/kg of body weight at each meal (roughly 31 g of protein per meal or 93 g per day for a 170-pound person) to encourage maximum protein synthesis.

This represents a significantly higher amount of protein than the recommended dietary allowance (RDA) suggests.”

The study,2 published in the American Journal of Physiology Endocrinology and Metabolism, assessed the effects of four eating plans on the muscle health of 20 healthy adults between the ages of 52 and 75.

The participants were randomly divided into four groups, and assigned to a specific eating plan as follows:

  • Groups 1 and 2 ate 0.8 grams of protein per kilogram of body weight per day (current RDA); consumed either all at once during dinner, or divided up equally between three meals
  • Groups 3 and 4 ate 1.5 grams of protein per kilogram of body weight (double the current RDA guideline), either for dinner, or divided up equally between three meals

Regardless of the timing or distribution of the protein, after four days, those who ate more protein increased their rates of muscle protein synthesis, improving their body’s ability to build muscle. They also improved their net protein balance, which is the difference between protein synthesis and breakdown. As explained in the featured article:3

“As we age, we naturally lose muscle mass and strength due to a trifecta of reduced muscle response to protein intake, changing hormones and for some, less physical activity.

Called sarcopenia, this gradual loss of muscle mass has been credited with a litany of health problems, including insulin resistance, low bone mineral content and density, falls and fractures – even death, says lead author IL-Young Kim...

For maximal muscle, Kim says the majority of older adults need to consume about 1.8 grams of protein per kilogram of body mass per day. Kim recommends getting the bulk of your protein from animal sources such as beef, fish, milk and cheese.”

A Word of Caution—Too Much Protein Can Be Detrimental for Health 

As you age, your protein requirement will tend to increase, so there is some validity to the argument that that boosting protein intake may improve your health—if you’re currently eating far below the RDA. That said, there’s another side to this issue that you need to consider as well.

There is an upper limit to how much protein your body can actually use. And, on the average, Americans typically consume anywhere from three to five times more protein than they need for optimal health, along with far too many carbohydrates and insufficient amounts of healthy fats.

While your body certainly needs protein, eating too much of it—especially if you’re eating CAFO-raised protein—can actually be detrimental to your health for a number of reasons, including the following:

  • First, if you eat more protein than your body requires, it will simply convert most of those calories to sugar and then fat. Increased blood sugar levels can also feed pathogenic bacteria and yeast, such as Candida albicans (candidiasis), as well as fueling cancer cell growth
  • Excessive protein can have a stimulating effect on an important biochemical pathway called the mammalian target of rapamycin (mTOR). This pathway has an important and significant role in many cancers.

    When you reduce protein to just what your body needs, mTOR remains inhibited, which helps minimize your chances of cancer growth.

  • When you consume more protein than your body needs, your body must remove more nitrogen waste products from your blood, which stresses your kidneys.4 Chronic dehydration can result, as was found in a study involving endurance athletes5

So while it’s important to consume enough protein to maintain muscle mass, protein in and of itself is not a magic solution against sarcopenia (age-related muscle loss). You still need strength training to actually build muscle, and if you have cancer, you need to be particularly cautious about stimulating the mTOR pathway with excessive protein.

How Much Protein Is Likely ‘Enough?’

Dr. Ron Rosedale—a prominent expert on insulin—was possibly the first person to advocate both a moderate protein (and therefore high fat) and low-carb diet. For optimal health, he believes most adults need about one gram of protein per kilogram of LEAN body mass (not total body weight), or 0.5 gram of protein per pound of lean body mass.

To estimate your individual protein requirement, you must first determine your lean body mass. To do that, subtract your percent body fat from 100. For example, if you have 30 percent body fat, then you have 70 percent lean body mass. Then multiply that percentage (in this case, 0.7) by your current weight to get your lean body mass in pounds or kilos. As an example, if you weigh 170 pounds; 0.7 multiplied by 170 equals 119 pounds of lean body mass. Using the “0.5 gram of protein” rule, you would need 59.5 or just under 60 grams of protein per day.

100 – % of body fat = % of lean mass X actual weight X 0.5 gm protein = total grams of protein recommended

Example: A 170 lb. individual with 30% fat mass

100% total weight – 30% fat mass = 70 % lean mass

0.70 X 170 = 119 X 0.5 = 60 grams of protein recommended

For comparison, following the current US dietary guideline, which is based on total body weight, a 170-pound individual would need about 62 grams of protein per day. At first glance, these recommendations appear to be close enough to dissuade any arguing. The primary difference is that US guidelines do not take fat mass into account, which can vary wildly from one person to the next, even if they weigh the same. For example, if this theoretical 170-pound person has a fat mass of only 15 percent, his protein requirement would be just over 72 grams.

By factoring in fat mass and calculating protein need based on muscle weight (lean mass) instead of total weight, you can calculate your individual requirement far more precisely. Using this formula, most people’s protein requirement would fall in the 40-70 grams range, which is considerably lower than the average American’s consumption.

You must also remember that exercise uses protein and if you are walking 10,000 steps a day, you will likely need to increase your protein intake by 25 percent, making the lean 170-pound person have a protein need of about 90 grams per day. However even lean exercising individuals come far from the proposed recommendation in the featured study, which would suggest a 170 pound person needs 139 grams of protein a day (1.8 grams of protein per kilo of total body weight). Personally, I believe this is an excessive amount of protein and would recommend against these new guidelines unless you are clearly losing muscle mass. Then I would gradually increase along with strength training until you notice an improvement.

Meat consumption has risen dramatically in the US over the past century, yet it has not resulted in improved health. On the contrary, low-quality meat from confined animal feeding operations (CAFOs) has become a driver of both chronic disease and rising antibiotic-resistance.  I believe it would be rare for a person to need more than 0.5 grams of high quality protein per pound of lean body mass. Exceptions to the rule would be those who are aggressively exercising (or competing) and pregnant women, who typically need about 25 percent more. Seniors may also have slightly higher protein requirements. To learn more about protein requirements and recommended protein sources, please see my previous article, “The Very Real Risks of Consuming Too Much Protein.”

The Importance of Resistance Training

Moving on to the exercise portion of this discussion, resistance training or strength training is particularly important for healthy aging. Not only can it help counteract age-related muscle loss, but weight-bearing exercise is also one of the most effective remedies against osteoporosis. Loss of bone mass is a common sign of aging, because as you age your existing bone is absorbed by your body while new bone is created to replace it. In the case of osteoporosis, the formation of new bone falls behind the rate of bone absorption, leading to weakened, thinner and more brittle bones.

Strength training dynamically stimulates your osteoblasts or bone building cells to help build new bone. In addition, as you build more muscle you also increase the amount of constant tension on your bones, which also helps keep them strong and resilient. Strength training also increases your body’s production of growth factors, which are responsible for cellular growth, proliferation, and differentiation. Some of these growth factors also promote the growth, differentiation, and survival of neurons, which helps explain why working your muscles also benefits your brain and helps prevent dementia

Hip Fractures Becoming More Common Among Middle-Aged as Well as the Elderly

A thinning hipbone is a major concern if you are elderly, because any fall increases the risk of a broken hip, which can result in a fatal lung clot from immobilization. It's estimated that 25 percent of elderly people suffering a hip fracture actually die as a direct result, usually from the blood clot.6 According to the latest government statistics,7 the number of hip replacements substantially increased between 2000 and 2010. The procedure has also become increasingly common among younger people, which is a clear warning sign that our lifestyles are in dire need of reassessment!

Over that 10-year span, total hip replacements more than doubled, from 138,700 in 2000 to 310,800 in 2010. Among 45 to 54-year olds, the number rose by 205 percent! In all, 51,900 hip replacement procedures were performed on people aged 45-54. Compare that to 80,000 procedures performed on seniors aged 75 and older. Rising arthritis rates are thought to contribute to this rapid rise in hip replacements among the middle-aged, but my guess is that improper diet and lack of exercise are the real culprits. Chronic sitting may also be part of the problem. Prolonged sitting may actually be more hazardous to your health than lack of exercise in general.

Weight Training Tips for Older Adults

Examples of muscle-strengthening exercises include yoga, body-weight exercises, and resistance training using elastic bands and/or free weights or weight machines. The American College of Sports Medicine, the American Heart Association, and the US Department of Health and Human Services (DHHS) recommend engaging in muscle strengthening activities targeting all major muscle groups at least two days per week.8

Remember, you are never too old to start exercising. My mom is an excellent example, as she didn't start working out until she was 74 and has since gained significant improvements in strength, range of motion, balance, bone density, and mental clarity at the age of 80. After a bit of apprehension at first, she now, as you can see in the video above, loves her workouts and, I'm hoping, will inspire you to get active as well, no matter what your age.

If you’re just starting out, consult with a personal fitness trainer who can instruct you about proper form and technique. He or she can also help you develop a plan based on your unique fitness goals and one that is safe for any medical conditions you may have. Keep in mind that while you need to use caution, you do need to exercise at a level that is challenging to your body. Many make the mistake of not exercising with enough intensity, and this will result in many of your benefits being forfeited.

One beneficial and safe way to incorporate high-intensity exercise into your workout if you’re older is to slow down your movements. This technique, referred to as super-slow weight training, is also very efficient in terms of time. You only need about 12 to 15 minutes of super-slow strength training once a week to achieve the same human growth hormone (HGH) production as you would from 20 minutes of Peak Fitness sprints (which may be unsuitable for the elderly). Dr. Doug McGuff is an avid proponent of this technique. I’ve also started incorporating an even more intense version, called super-super-slow strength training.

If you still have not incorporated high intensity exercise into your fitness regimen, I highly recommend getting started. You can learn more about HIIT here,9 as there are many different programs to choose from. I also review the similarities and differences between super-slow and super-super-slow strength training techniques in this previous article.10

With Diet and Exercise, You Can Stay Active and Limber Well Into Old Age

Regardless of your age, diet and exercise are foundational components that can help you live a long and healthy life. With total hip replacements now being performed on people in their 40s, it would certainly behoove you to consider the price you may have to pay for ignoring your diet and fitness... When it comes to diet, protein is but one part of the equation, and as mentioned, there is a goldilocks’ zone—you do need protein for bone and muscle health, but too much can stimulate the mTOR pathway, thereby raising your risk for cancer and other health problems.

For optimal health, most people need about one gram of protein per kilogram of lean body mass (not total body weight), or one-half gram of protein per pound of lean body mass, as discussed above. Increase that by 25 percent for extensive exercise, like walking or running 6-8 miles per day. Also be mindful of the quality of your protein. Most meats and animal products on the market are typically poor quality, originating in CAFOs, where the animals are mistreated and fed an unnatural diet of genetically engineered grains instead of fresh grass.

So, your goal should be a diet with enough—but not too much—high-quality protein from a variety of animal and plant sources. Then, consider adding strength training to your regimen, to boost muscle tone and bone health. While everyone can benefit from super-slow strength training, this technique may be particularly suitable if you’re middle-aged or older, as it tends to be a safer form of high intensity exercise compared to sprinting. You do not have to become infirm with advancing age. But you do need to be proactive, and the earlier you start, the better off you’ll be.