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Dr. Nick Burd, PhD, is a skeletal muscle physiologist with an expertise in protein metabolism and exercise. In this episode, Dr. Burd discusses the importance of maintaining muscle mass as we age, expressing that “strong is the new healthy.”
While adequate protein intake is an important aspect of gaining muscle and maintaining healthspan, many people in the US actually over consume protein. In this discussion, Dr. Burd talks about how much protein we truly need, whether or not there is an optimal time to consume protein after exercise, and how to best distribute protein intake throughout the day. He explains why consuming protein from food sources rather than as a powder may be better for muscle growth, and shares why protein is critical for endurance athletes.
Episode highlights
- Introduction: (0:00–1:50)
- Why Dr. Burd became a scientist (1:50–4:00)
- The three types of muscle (4:00–5:00)
- How much of our muscle mass is skeletal muscle? (5:00–5:40)
- How obesity impacts muscle mass (5:40–8:16)
- What is a DEXA scan (8:16–10:30)
- Benefits of exercise on skeletal muscle (10:30–14:00)
- Sedentary behavior is detrimental to muscle tissue (14:00–19:00)
- “Strong is the new healthy” (19:00–20:00)
- Skeletal muscle and metabolic health (20:00–22:00)
- Many people over consume protein (22:00–26:50)
- Is there an optimal time to consume protein after exercise? (26:50–31:30)
- Protein powders vs. whole food sources of protein (31:30–35:50)
- Distribution of protein throughout the day (33:50–45:34)
- Why protein is important for endurance athletes (45:34–51:20)
- Protein needs for different ages, ethnicities, and gender (51:20–55:20)
- Resistance training in post menopausal women (55:20–1:01:00)
- Top tip for healthspan (1:01:00–end)
About Dr. Burd
Dr. Nick Burd, PhD, is an associate professor in the department of kinesiology and community health at the University of Illinois. Dr. Burd’s area of research interest is nutrition and exercise metabolism. His research group commonly uses stable isotope tracers of amino acids to understand how exercise, nutrition, or disease may regulate skeletal muscle mass (e.g., protein synthesis). He received his PhD in Kinesiology from McMaster University, Hamilton, in Canada.
Types of muscle tissue
There are three types of muscle tissue in the human body: skeletal, cardiac, and smooth muscle.
- Skeletal muscle is attached to bones and makes body movement possible
- Cardiac muscle forms the walls of the heart and powers its pumping action
- Smooth muscle lines internal organs and vessels, aiding involuntary motions
Muscle tissue is highly adaptive to exercise
All types of muscle tissue in the body have the capacity to positively adapt to exercise. For example, skeletal muscles renew themselves and increase protein production, the heart muscle strengthens allowing for greater blood flow, and mitochondrial and capillary production increases to meet energy demands. Both resistance training and endurance exercise can lead to these beneficial muscular alterations across muscle types.
Training specificity impacts muscle adaptation
The stimulus of exercise tells our muscles to remodel and adapt based on the specific stress placed on them. This concept is known as training specificity. For example, weightlifting triggers muscle hypertrophy or growth in size due to increased protein synthesis leading to enlargement of contractile myofibrillar proteins that generate force. Over time, these acute bursts culminate in bigger skeletal muscles. Meanwhile, endurance exercise also remodels contractile proteins but in a way that enhances fatigue resistance.
How does aging impact muscle tissue?
We often hear that as we age, it is harder to build and maintain muscle. Dr. Burd argues the age-related decline in muscle mass is a consequence of increased sedentary behavior. As we get older, many tend to participate less in regular exercise while simultaneously increasing sedentary behavior. Prolonged inactivity progressively blunts skeletal muscle's sensitivity and responsiveness—both to nutrition and to exercise itself when attempted sporadically later on. However, research suggests that if older adults can preserve movement, they can largely retain muscle function.
Dr. Burd also explains that muscle tissue does not intrinsically “know” its age at the molecular level. Healthy 70-year-olds can still adapt to training, building muscle when following a regular exercise routine. “It does appear that once we hit 80, the molecular environment starts to change and muscle tissue has a harder time adapting,” says Dr. Burd.
Avoiding sedentary behavior with exercise “snacks” throughout the day
Individuals who regularly exercise can still live rather sedentary lives. Dr. Burd expresses this is typical of a working adult in the US—they may spend an hour exercising vigorously in the morning, but then spend 8+ hours working on a computer. Sedentary behavior blunts muscle stimuli sensitivity and is detrimental to health.
Rather than solely relying on concentrated exercise blocks, Dr. Burd recommends building more constant movement into daily routines—what he likes to call “exercise snacks.” If you find yourself sitting for extended periods, interrupt that inactivity by getting up and moving around. Whether through body weight exercises or a 10-15 minutes walk, the key is breaking up sedentary time. Muscle activation depends on regular activity sprinkled throughout the day: exercise sessions develop strength and fitness, but ongoing motion maintains muscle sensitivity and metabolic health.
Skeletal muscle tissue impacts metabolic health
Skeletal muscle plays an important role in metabolic health. Dr. Burd declares that “strong is the new healthy,” and explains some of the ways that having healthy muscles can improve metabolism.
- Skeletal muscle is the largest site of postprandial glucose disposal, which helps maintain normal blood sugar levels.
- Skeletal muscle is a strong determinant of basal metabolic rate, which for most people is the biggest contributor to total daily energy expenditure.
Losing muscle mass slows metabolism, hindering weight control and glucose regulation. This is especially detrimental after dieting-induced weight loss, as metabolic rate dips. So preserving muscle function helps maintain energy expenditure and healthy metabolism over time.
How to be smarter about protein intake with Dr. Burd
In addition to being an expert in muscle physiology, Dr. Burd has done extensive research on protein. In the second half of this episode, Dr. Burd talks about all things protein nutrition—giving practical advice to listeners to be smarter about their protein intake. Let’s dive in.
Weight training causes your body to better utilize dietary protein
Weightlifters often over-consume protein, believing more protein means more muscle growth. However, weight training actually improves muscles' ability to utilize protein to build mass. Even though lifting primes muscles to use protein efficiently, eating excessive protein causes protein waste - amino acids get diverted away from muscles. So despite weight training enhancing protein use for muscle growth, eating far more protein than needed creates an inefficient system where protein gets burned or removed rather than used by muscles.
Dr. Burd’s advice for protein intake: eat between 0.8-1.2 grams of protein per kg of body weight per day.
What is the optimal time to consume protein after a workout?
Despite some persistent myths, the so-called "anabolic window" for taking in protein after training is wider than people often believe. Weight training triggers a sustained rise in muscle protein synthesis that remains elevated for hours. While this increase in muscle protein synthesis slowly declines as time passes post workout, it is still elevated at six hours compared to baseline.
While quicker protein intake may optimize the muscle growth response, lifters don't need to rush and can focus on higher quality nutrition. “Just get an adequate protein meal within several hours, there’s no need to consume a protein shake immediately after a workout,” says Dr. Burd.
Key takeaway: To maximize the anabolic potential of an exercise bout, consume a high protein meal within 3 hours.
Are protein shakes better than protein from a meal?
Dr. Burd recommends a food first approach for optimal protein nutrition—meaning choosing high protein meals rather than a shake with protein powder to refuel post exercise. Whole foods not only provide quality complete proteins, but an entire nutritional package including fats, carbohydrates, vitamins, minerals and other beneficial compounds. This complete food matrix offers advantages over isolated proteins.
Bottom line: Choose food sources of protein powders, but supplement with protein powders when necessary.
Overconsumption of whey protein can be counterproductive to muscle growth
Whey protein powder is popular amongst weightlifters because it digests quickly, spiking blood amino acids within 60-90 minutes post-consumption. Dr. Burd explains that aggressively elevating amino acids over a short period stimulates breakdown rather than productive muscle building pathways—wasting much of the amino acid load from supplemental whey.
In contrast, slower-digesting whole food proteins cause a moderate but prolonged amino acid rise over 2+ hours, better supporting sustainable muscle growth for most exercisers.
Should we consume protein prior to exercise?
Despite claims that pre-workout protein enhances performance, the majority of research does not support muscle or strength benefits from consuming protein before rather than after training. The primary downside of pre-workout protein is possible gastrointestinal distress—having a large protein meal sitting in the stomach can cause discomfort when attempting demanding multi-joint lifts like heavy squats or deadlifts. Ultimately, the priority should be adequate protein intake within the few hours after a workout rather than before. Consuming protein prior provides no advantage while increasing likelihood of stomach issues during training.
High protein breakfasts can improve satiety and blood glucose regulation throughout the day
While discussing protein distribution throughout the day, Dr. Burd highlights that consuming a protein-rich breakfast is important. Research shows that higher protein breakfasts provide better post-meal glucose control and promote increased feelings of fullness that help manage calorie intake throughout the day. Breakfast is consistently shown to be the lowest protein meal of the day, therefore represents an opportunity to easily increase daily protein intake.
Protein recommendations for endurance athletes
Protein is a critical fuel source for endurance sports, as it facilitates optimal recovery and helps rebuild muscles. During prolonged exercise, specific amino acids like leucine get oxidized directly by muscles to help fuel metabolism. Endurance sports break down amino acid resources that then require replenishing. These athletes also need adequate protein to rebuild damaged muscle proteins strained from persistent contraction.
Key takeaway: After a run, Dr. Burd recommends consuming about 20 grams of protein and 50 grams of carbohydrate within an hour.
Top tip for healthspan
Dr. Burd’s top tip for health is to move consistently. He says it matters less how you exercise, just that you find activities you genuinely enjoy and maintain them regularly.
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