How do we fight the battle with Sarcopenia as we age?

What about Protein Digestion & Absorption? 

Glucose and Carb Timing?

Keto? Fasting?

What about Insulin Resistance? 

Cortisol?  Too much of anything…

Does INSULIN get a bad rap as we are told not to ingest carbohydrate rich foods before easy (Zone 1/2) endurance training session because we will increase glucose and signal insulin to be release to lower blood glucose levels -and that will impact fat oxidation rate.

I started thinking today as I research for my new Longevity group online program – are we now afraid of release insulin?  Does insulin impact our ability to burn fat?  Does insulin impact our ability to build muscle via muscle protein synthesis?

My RABBIT HOLE of the day.

The Insulin Response.

First ..what is Muscle Protein Synthesis (MPS):

Muscle protein synthesis is the process by which the body builds new proteins within muscle cells. This process involves the incorporation of amino acids into muscle proteins, leading to muscle growth, repair, and maintenance. Muscle protein synthesis occurs in response to various stimuli, with resistance exercise and protein intake being two primary factors that stimulate this process.

When you engage in resistance exercise, it causes microdamage to muscle fibers. In response to this damage, the body initiates muscle protein synthesis to repair and build new muscle proteins. Protein intake, particularly the presence of essential amino acids, provides the building blocks necessary for this synthesis.

What is the Leucine Threshold:

The concept of a leucine threshold refers to the idea that there is a specific threshold level of the branched-chain amino acid leucine that must be reached to maximally stimulate muscle protein synthesis. Dr. Donald Layman, a researcher in the field of nutrition and protein metabolism, has contributed significantly to our understanding of the importance of leucine in promoting muscle protein synthesis.

While the specific threshold may vary among individuals and depends on factors such as age, fitness level, and the presence of other amino acids, a commonly cited figure is around 2-3 grams of leucine per meal. This means that, ideally, a meal should provide at least this amount of leucine to robustly stimulate muscle protein synthesis.

Key points related to the leucine threshold and muscle protein synthesis include:

Leucine as a Trigger for Muscle Protein Synthesis:

Leucine is one of the essential amino acids and is particularly important in initiating the mTOR pathway, a key regulator of muscle protein synthesis.
Role of Other Amino Acids:

While leucine is crucial, the presence of other essential amino acids is also necessary for optimal protein synthesis. Leucine is considered the “trigger,” but a complete profile of amino acids is required for building proteins.

Protein Quality and Timing:

Protein quality, which includes the amino acid composition and digestibility, is essential for supporting muscle protein synthesis.
The timing of protein intake, especially around the time of exercise, can also influence the muscle protein synthesis response.

Individual Variability:

The leucine threshold can vary among individuals. Factors such as age, training status, and overall protein needs influence the individual response to leucine and protein intake.

Optimizing Protein Intake:

To meet the leucine threshold and support muscle protein synthesis, individuals should focus on consuming high-quality protein sources in their meals.
Protein-rich foods such as meat, poultry, fish, dairy, eggs, and plant-based sources like soy can contribute to meeting leucine and overall amino acid needs.

It’s important to note that the field of nutrition and muscle protein synthesis is dynamic, with ongoing research providing deeper insights. Dr. Donald Layman’s work has been influential in emphasizing the importance of leucine and protein quality in promoting muscle protein synthesis.

For personalized advice on protein intake, particularly in relation to the leucine threshold, individuals may benefit from consulting with a registered dietitian or nutrition professional who can consider their specific needs, goals, and dietary preferences.

Leucine is one of the essential amino acids, and it plays a crucial role in initiating muscle protein synthesis.

• The leucine threshold refers to the minimum amount of leucine needed to maximize the muscle protein synthetic response.
• Leucine is a branched-chain amino acid (BCAA) that activates a signaling pathway, particularly the mammalian target of rapamycin (mTOR), which is a key regulator of muscle protein synthesis.
• Research suggests that a threshold amount of leucine in a protein-containing meal is necessary to stimulate optimal muscle protein synthesis.
• Foods rich in leucine include meat, poultry, fish, eggs, dairy products, and certain plant sources like soybeans.

Essential Amino Acids and Complete Proteins:

• Essential Amino Acids (EAAs): These are amino acids that the body cannot produce on its own and must be obtained through the diet. There are nine essential amino acids, including leucine.
• EAAs are crucial for stimulating muscle protein synthesis, and a balanced intake of all essential amino acids is important for overall protein synthesis.

Complete Proteins:

• Foods that contain all nine essential amino acids in sufficient quantities are termed complete proteins. Animal-based sources such as meat, fish, poultry, eggs, and dairy products are typically complete proteins.
• Some plant-based sources, such as quinoa and soy, are also complete proteins. Consuming complete protein sources ensures that the body has all the necessary building blocks to support muscle protein synthesis.

Quinoa is a pseudo-grain that is considered a complete protein, as it contains all nine essential amino acids??.

• Quinoa Serving Size: One cup of cooked quinoa typically contains around 8 grams of protein.
• Calories per Cup:  Cooked quinoa generally provides approximately 220 calories per cup.
• To get 30-50 grams of complete protein from quinoa, you would need to consume approximately 4-6 cups of cooked quinoa.
• Keep in mind that this also means a higher calorie intake, so it’s important to consider your overall dietary goals and requirements.

Requirements for Muscle Building Health for LONGEVITY:

Protein Intake: Adequate protein intake is essential for muscle building. The exact protein requirements can vary based on factors such as age, activity level, and individual goals. General recommendations often suggest a protein intake of around 0.8 to 1.0 grams of protein per pound of ideal body weight per day for individuals engaged in resistance training to promote muscle protein synthesis (Dr. Lyon).

Meal Timing: Distributing protein intake evenly throughout the day, including post-exercise, can be beneficial for maximizing muscle protein synthesis.

Resistance Exercise: Engaging in regular resistance exercise is a key stimulus for muscle protein synthesis. The combination of resistance training and adequate protein intake is a powerful strategy for promoting muscle growth.

In summary, muscle protein synthesis is a dynamic process crucial for muscle health, repair, and growth.

Ensuring an adequate intake of protein, especially essential amino acids like leucine, and engaging in regular resistance exercise are fundamental for optimizing muscle protein synthesis and supporting muscle building goals.

What about Insulin?

Insulin is a hormone produced by the pancreas, and it plays a crucial role in regulating various metabolic processes, including the uptake of glucose into cells for energy production. Additionally, insulin has anabolic effects, meaning it promotes the synthesis of molecules and the buildup of tissues. One of the anabolic actions of insulin is its influence on muscle protein synthesis.

Here’s how insulin functions as an anabolic hormone in relation to muscle protein synthesis:

Glucose Uptake:

• Insulin facilitates the uptake of glucose by cells, including muscle cells.
• Glucose serves as an important energy source during physical activities, including exercise.
• By promoting glucose uptake, insulin helps provide energy to muscle cells, supporting their function during exercise.

Amino Acid Uptake:

• Insulin also enhances the uptake of amino acids, including essential amino acids, into cells.
• Amino acids are the building blocks of proteins, and this increased uptake is particularly relevant for muscle cells.
• The availability of amino acids is crucial for initiating and sustaining muscle protein synthesis.

mTOR Activation:

• Insulin activates the mammalian target of rapamycin (mTOR) pathway.
• The mTOR pathway is a key regulator of protein synthesis, and its activation promotes the translation of messenger RNA (mRNA) into proteins.
• This includes the translation of mRNA involved in muscle protein synthesis.

Now, regarding insulin resistance and its potential impact on muscle protein synthesis in aging females, there are several considerations:

Insulin Resistance and Aging:

Insulin resistance is a condition in which cells become less responsive to the effects of insulin. This resistance can lead to higher levels of insulin in the bloodstream.

Aging is associated with an increased risk of insulin resistance, and this can be influenced by factors such as changes in body composition, physical activity levels, and hormonal changes.

Estrogen and Insulin Sensitivity:

Estrogen, a hormone primarily associated with females, has been shown to have insulin-sensitizing effects. In premenopausal women, estrogen helps maintain insulin sensitivity.
As women go through menopause and estrogen levels decline, there is an increased risk of insulin resistance. This decline in estrogen may contribute to changes in body composition and metabolic function.

Impact on Muscle Protein Synthesis:

Insulin resistance can negatively impact muscle protein synthesis by impairing the normal anabolic responses to insulin.

Reduced insulin sensitivity may lead to decreased glucose and amino acid uptake by muscle cells, potentially hindering the initiation and maintenance of muscle protein synthesis.

Lifestyle Interventions:

Lifestyle interventions, including regular exercise and a healthy diet, can help improve insulin sensitivity.
Resistance exercise, in particular, has been shown to enhance insulin sensitivity and promote muscle protein synthesis.
In summary, insulin is an anabolic hormone that plays a role in muscle protein synthesis by facilitating glucose and amino acid uptake and activating the mTOR pathway. Insulin resistance, which can occur with aging and be influenced by hormonal changes such as reduced estrogen levels, may compromise these processes. Maintaining a healthy lifestyle, including regular exercise and a balanced diet, is essential for supporting insulin sensitivity and optimizing muscle protein synthesis, especially in the context of aging. Consulting with healthcare professionals can provide personalized guidance based on individual health status and needs.

Explain the role of insulin and muscle health for aging

Insulin plays a significant role in muscle health, and its functions are particularly relevant in the context of aging. Here are key aspects of the relationship between insulin and muscle health in the aging process:

Glucose Uptake and Energy Metabolism:

• Insulin facilitates the uptake of glucose into cells, including muscle cells.
• This process is crucial for providing energy to muscles during various activities, including exercise.
• In aging individuals, there is often a decline in insulin sensitivity, leading to impaired glucose uptake.

This insulin resistance can result in higher blood glucose levels, which may negatively impact muscle function and overall health.

Amino Acid Uptake and Protein Synthesis:

Insulin promotes the uptake of amino acids, including essential amino acids, by cells.

Amino acids are the building blocks of proteins.

Adequate insulin function is essential for supporting muscle protein synthesis, which is crucial for the maintenance, repair, and growth of muscle tissue.

mTOR Activation:

Insulin activates the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway is a key regulator of protein synthesis, playing a central role in the growth and maintenance of muscle mass.

Proper mTOR activation by insulin is necessary for optimal muscle protein synthesis, and disruptions in this pathway can contribute to age-related muscle loss (sarcopenia).

Insulin Resistance and Aging:

Aging is often associated with a decline in insulin sensitivity, leading to insulin resistance.

This means that cells, including muscle cells, become less responsive to the effects of insulin.
Insulin resistance can contribute to metabolic dysfunction, higher blood glucose levels, and impaired muscle protein synthesis.

Impact on Sarcopenia:

• Sarcopenia, or age-related muscle loss, is a common condition in older adults.
• Insulin resistance may contribute to the development and progression of sarcopenia.
• Reduced insulin sensitivity can impair the anabolic response of muscles to nutrients and exercise, further exacerbating muscle loss.

Lifestyle Interventions:

• Engaging in regular physical activity, particularly resistance exercise, can improve insulin sensitivity and support muscle health.
• Maintaining a balanced diet with an emphasis on protein intake and avoiding excessive consumption of refined carbohydrates can also positively influence insulin function and muscle health.

Hormonal Changes:

Hormonal changes associated with aging, such as declines in growth hormone and sex hormones, can also impact insulin sensitivity and muscle health.
For example, postmenopausal women may experience changes in estrogen levels, which can contribute to insulin resistance and alterations in body composition.

Preventing Insulin Resistance:

Adopting a healthy lifestyle that includes regular exercise, a balanced diet, and weight management is crucial for preventing or mitigating insulin resistance.
Strategies such as intermittent fasting and resistance training have shown promise in improving insulin sensitivity and supporting muscle health in aging populations.

In conclusion, insulin plays a multifaceted role in supporting muscle health by regulating glucose and amino acid uptake, activating protein synthesis pathways, and influencing energy metabolism. As individuals age, maintaining insulin sensitivity through lifestyle interventions becomes increasingly important for preserving muscle mass, preventing sarcopenia, and promoting overall health. Consulting with healthcare professionals or registered dietitians can provide personalized guidance on nutrition, exercise, and lifestyle choices tailored to individual needs and health status.

Does nutritional ketosis and high fat diet – fear of raising glucose and stimulating insulin connect to loss of muscle mass and muscle protein synthesis?

The relationship between nutritional ketosis, a high-fat diet, glucose levels, insulin response, and their impact on muscle mass and protein synthesis is a complex interplay that depends on several factors.

Let’s break down the key components:

Nutritional Ketosis and High-Fat Diet:  Nutritional ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood, often achieved through a low-carbohydrate, high-fat diet.  A high-fat diet, particularly when carbohydrates are restricted, prompts the body to use ketones and fat for energy instead of glucose.

Glucose Levels and Insulin Response: Carbohydrate intake is the primary determinant of blood glucose levels. A low-carbohydrate diet or nutritional ketosis typically results in lower blood glucose levels. Insulin is released in response to elevated blood glucose levels to facilitate glucose uptake by cells. With lower carbohydrate intake, insulin levels tend to be lower.

Impact on Muscle Mass and Protein Synthesis: There is ongoing research regarding the impact of nutritional ketosis and high-fat diets on muscle mass and protein synthesis.  Some studies suggest that a well-formulated ketogenic diet may preserve muscle mass, particularly when sufficient protein is consumed and resistance exercise is incorporated.  However, concerns have been raised about potential drawbacks, such as the initial loss of water weight, and the need for careful planning to ensure an adequate intake of essential nutrients.

Protein Intake:  Protein intake is a critical factor in muscle health and protein synthesis. Adequate protein is necessary to provide amino acids for building and repairing muscle tissue. While ketogenic diets are often moderate in protein, ensuring an appropriate protein intake is crucial for supporting muscle health.

Insulin and Anabolic Signaling:  Insulin is considered an anabolic hormone that plays a role in promoting protein synthesis. However, this does not mean that insulin must be consistently elevated for muscle protein synthesis to occur.  Emerging research suggests that the relationship between insulin and muscle protein synthesis is complex, and other factors, such as amino acid availability and resistance exercise, also contribute significantly.

Individual Variation:  Responses to nutritional ketosis and high-fat diets can vary among individuals. Factors such as age, activity level, metabolic health, and overall dietary composition influence these responses.

It’s important to note that nutritional strategies, including ketogenic diets, should be approached with careful consideration of individual health goals and needs. While some individuals may benefit from such diets, others may not. Additionally, the potential impact on muscle health should be monitored, and adjustments made as necessary.

In summary, the relationship between nutritional ketosis, high-fat diets, glucose levels, insulin response, and their impact on muscle mass and protein synthesis is an area of active research. While some studies suggest potential benefits, individual responses can vary, and further research is needed to fully understand the long-term effects and potential drawbacks of these dietary approaches on muscle health. Consulting with healthcare or nutrition professionals can provide personalized guidance based on individual circumstances and goals.

Does insulin released from a carb heavy meal pre endurance exercise impact performance?

The impact of insulin released from a carbohydrate-heavy meal on endurance exercise performance is influenced by various factors, including the timing of the meal, the type and amount of carbohydrates consumed, and individual differences. Here are some key considerations:

Timing of the Meal:

Consuming a carbohydrate-rich meal before endurance exercise can provide a source of readily available energy (glycogen) to support performance.
The timing of the meal matters. Consuming carbohydrates 1-4 hours before exercise allows for the digestion and absorption of nutrients, leading to increased glycogen availability during the activity.

Type and Amount of Carbohydrates:

The type of carbohydrates consumed can affect the insulin response. Simple carbohydrates (e.g., sugars) typically lead to a quicker spike in blood glucose and insulin levels than complex carbohydrates (e.g., whole grains, vegetables).
Consuming moderate to high glycemic index carbohydrates may result in a more rapid increase in blood glucose and insulin, potentially providing a quicker energy source for the upcoming exercise.

Individual Response:  Individual responses to meals can vary. Some people may experience a more pronounced insulin response than others based on factors such as insulin sensitivity and metabolic health.  Athletes may have different preferences and tolerances for the timing and composition of pre-exercise meals.

Insulin and Exercise Performance:  In general, a moderate increase in insulin from a pre-exercise carbohydrate-rich meal is not considered detrimental to endurance performance.  Insulin helps facilitate the uptake of glucose into cells, contributing to the replenishment of glycogen stores in the muscles and liver, which can be beneficial during prolonged endurance activities.

Balancing Blood Glucose Levels:  Consuming carbohydrates with protein and/or fats can help mitigate rapid spikes and crashes in blood glucose levels, providing a more sustained source of energy. Balancing macronutrients in the pre-exercise meal may help stabilize blood sugar levels and prevent hypoglycemia during prolonged exercise.

Personalized Approach:  Athletes often benefit from individualized nutrition strategies based on their specific needs, preferences, and responses to different foods.  Experimenting with different pre-exercise meals and observing how they impact performance can help individuals identify what works best for them.

In conclusion, a carbohydrate-rich meal before endurance exercise can positively impact performance by providing a source of energy to support glycogen stores. The insulin response to such a meal is generally considered beneficial for facilitating glucose uptake. However, individual responses can vary, and athletes may need to experiment with different meal timing and compositions to optimize their pre-exercise nutrition strategy. Consulting with a sports nutrition professional or registered dietitian can provide personalized guidance based on individual needs and goals.

Is insulin bad for athletes?
Insulin itself is not inherently “bad” for athletes; rather, it plays a crucial role in regulating glucose metabolism and nutrient uptake, which are essential for energy production, recovery, and overall athletic performance. However, like any hormone, the context and timing of insulin release can influence its impact on an athlete’s goals.

Here are some considerations regarding insulin and its role for athletes:

Muscle Glycogen Storage: Insulin facilitates the uptake of glucose into cells, including muscle cells. This is particularly important for replenishing glycogen stores in muscles after exercise, which is crucial for recovery and preparing for subsequent workouts.

Protein Synthesis: Insulin also has an anabolic effect, promoting protein synthesis. This is important for muscle repair and growth, especially when combined with adequate protein intake.

Balancing Blood Glucose Levels: Athletes, especially endurance athletes, rely on a balance of energy sources, including carbohydrates, during exercise. Insulin helps regulate blood glucose levels, preventing excessive increases or decreases that could negatively impact performance.

Nutrient Timing: The timing of insulin release, especially in relation to meals and exercise, can influence its impact on energy metabolism. Consuming carbohydrates and protein around the time of exercise can elicit an insulin response that supports nutrient uptake and recovery.

Individual Variability: Responses to insulin can vary among individuals based on factors such as insulin sensitivity, metabolic health, and genetics. Some athletes may have more robust insulin responses, while others may be more insulin resistant.

While insulin has many positive roles for athletes, there are considerations to keep in mind:

Insulin Sensitivity: Chronic exposure to high levels of insulin, such as in insulin resistance, can have negative health implications. Athletes, like the general population, should strive for insulin sensitivity through regular physical activity, a balanced diet, and weight management.

Nutrient Composition: The composition of meals, especially the balance of carbohydrates, proteins, and fats, can influence the insulin response. Athletes may benefit from individualized nutrition strategies based on their specific needs and goals.

Potential for Weight Gain: Excessive calorie consumption, especially from high-carbohydrate and high-fat foods, can contribute to weight gain. Athletes need to consider their energy needs and balance their intake with expenditure.

In summary, insulin is not inherently “bad” for athletes; it is a hormone with crucial roles in energy metabolism and recovery. Athletes can leverage the positive effects of insulin through smart nutrient timing, balanced meals, and a focus on overall metabolic health. Individualized nutrition plans, tailored to an athlete’s specific needs and goals, are important for optimizing the impact of insulin on athletic performance. Consulting with a sports nutrition professional or registered dietitian can provide personalized guidance.

What is the insulin response and optimal amount to avoid blunting fat oxidation but also to improve muscle protein synthesis?

The insulin response is the release of insulin by the pancreas in response to elevated blood glucose levels, typically following the consumption of carbohydrates.

Insulin plays a vital role in nutrient regulation and has both anabolic (building) and anti-catabolic (preventing breakdown) effects on various tissues, including muscle.

The optimal insulin response to balance fat oxidation and muscle protein synthesis can be achieved through a strategic approach to nutrient timing and composition.

Here are some considerations:

Timing of Nutrient Intake:  Nutrient timing plays a crucial role in optimizing the insulin response. Around the time of exercise, the body is more insulin-sensitive, making it an opportune time for nutrient uptake.
Consuming a balanced meal or snack containing carbohydrates and protein within the peri-workout (pre-, intra-, or post-exercise) period can help maximize the anabolic effects of insulin.

Carbohydrate Intake:  Consuming carbohydrates triggers insulin release. The type and amount of carbohydrates can influence the insulin response.
For individuals looking to avoid blunting fat oxidation, it may be beneficial to focus on low to moderate glycemic index carbohydrates. These carbohydrates result in a slower, more sustained increase in blood glucose and insulin levels compared to high-glycemic-index options.

Protein Intake: Including protein in meals can enhance the insulin response and support muscle protein synthesis.
Adequate protein intake, especially containing essential amino acids like leucine, is crucial for maximizing the anabolic response to insulin.

Balancing Macronutrients: Balancing macronutrients in meals can help achieve a more gradual and sustained insulin response.
Combining carbohydrates with protein and healthy fats can promote a more balanced energy profile and support both fat oxidation and muscle protein synthesis.

Individual Variability: Individual responses to nutrient intake and insulin can vary based on factors such as genetics, insulin sensitivity, and overall health.
Experimenting with different nutrient compositions and observing personal responses can help individuals tailor their approach.
It’s important to note that the relationship between nutrient intake, insulin response, fat oxidation, and muscle protein synthesis is complex and can be influenced by various factors. Additionally, individual goals and metabolic considerations can impact the optimal approach for different individuals.

Ultimately, working with a registered dietitian or sports nutrition professional can provide personalized guidance based on individual needs, preferences, and goals. They can help design a nutrition plan that optimally supports both fat oxidation and muscle protein synthesis while considering individual variability and the context of meals in relation to exercise.