When we think about body recomposition (aka drop fat and build muscle), most of us assume that diet and exercise are the most critical pieces. And while that may be true, it's equally as important to consider the role of hormones in this equation, including maintaining close control of insulin levels. To understand how to optimize insulin levels for muscle growth and function, we must first take a moment to understand what insulin is, and what role it plays in our physiology.
What Is Insulin?
Insulin has become a very popular hormone in mainstream media and social channels recently, primarily because of some fad drugs many celebrities use for weight loss.
Insulin is an anabolic (aka storage) hormone released by the beta islet cells of the pancreas in response to rises in glucose levels. This growth hormone helps the body process carbohydrates by signalling cells in the muscles, heart and liver to uptake glucose from the bloodstream to either process it as energy or store it for later use. Interestingly, it also regulates the breakdown of muscle proteins.
What is Insulin Resistance?
Insulin resistance is a metabolic condition characterized by the body's reduced sensitivity or responsiveness to the effects of insulin. It occurs when cells become less able to efficiently take up and utilize glucose in response to insulin signalling. Several factors contribute to the development of insulin resistance:
Obesity: Excess body fat, particularly visceral fat (fat around the abdominal organs) is strongly associated with insulin resistance. Adipose tissue releases inflammatory substances called adipokines, which interfere with insulin signalling and disrupt glucose uptake.
Sedentary lifestyle: Lack of physical activity and a sedentary lifestyle contribute to the development of insulin resistance. Regular exercise improves insulin sensitivity, allowing cells to respond better to insulin and utilize glucose.
Genetics: Family history and certain genetic factors can predispose individuals to insulin resistance. Specific gene variants are associated with impaired insulin signalling and glucose metabolism. However, it's important to remember that genetics alone do not determine the development of insulin resistance - environment and lifestyle factors almost always play a role.
Processed diet: A diet high in refined carbohydrates, sugary foods, and saturated fats can contribute to insulin resistance. Consuming excessive amounts of these foods can lead to chronically elevated blood sugar levels and subsequent insulin overproduction, leading to insulin resistance over time.
Chronic inflammation: Inflammation, often associated with conditions like obesity and metabolic syndrome, can interfere with insulin signalling pathways and promote insulin resistance.
Over time, insulin resistance can lead to the development of type 2 diabetes, as the pancreas compensates by producing more insulin to overcome the reduced effectiveness of insulin. As such, prolonged insulin resistance can overwhelm the pancreas and cause it to fail, leading to insulin deficiency and high blood sugar levels.
How Does Insulin Affect Muscles?
Insulin plays a crucial role in muscle development by regulating various metabolic processes. When insulin is released by the pancreas in response to increased blood sugar levels, it facilitates the uptake of glucose into muscle cells. This glucose serves as an energy source for muscle contraction and replenishes glycogen stores for future use.
Furthermore, insulin promotes protein synthesis in muscle tissue. It stimulates the transportation of amino acids into muscle cells, which are the building blocks for protein synthesis. Increased insulin levels also inhibit protein breakdown, creating a more favourable environment for muscle growth and repair.
Insulin also aids in nutrient delivery to muscles by enhancing blood flow. It promotes vasodilation, leading to increased blood circulation and nutrient supply to muscle tissue. This ensures a sufficient oxygen and nutrient supply for optimal muscle function and growth.
However, it's important to note that while insulin supports muscle development, excessive insulin levels resulting from conditions like insulin resistance or diabetes can have negative effects. High insulin levels can contribute to fat storage and actually hinder muscle growth. Therefore, maintaining a balanced insulin response through a healthy diet, regular exercise, and proper insulin management is crucial for maximizing muscle development.
What This Means for You
It's important to note that finding optimal insulin balance is a complex task influenced by various factors. Maintaining a healthy weight, engaging in regular physical activity, following a balanced diet, and managing other metabolic risk factors are always key. However, there are a few strategies almost anyone can try to optimize muscle mass growth.
To improve insulin levels for muscle mass growth, here are some strategies that can be beneficial:
Balanced Diet: This one seems obvious, but still needs to be said. Focus on consuming a well-balanced diet (instead of cutting major foods like carbs or fats) that includes a variety of nutrient-dense foods. Include lean proteins, whole grains, fruits, vegetables, and healthy fats. Avoid excessive intake of refined sugars, alcohol, and processed foods, as they can negatively affect insulin sensitivity.
Macronutrient Distribution: Distribute macronutrients appropriately in your diet. Ensure an adequate intake of protein to support muscle growth and repair, as well as sufficient carbohydrates to provide energy for workouts and replenish glycogen stores. While the optimal protein intake for individuals can vary greatly, a good rule of thumb to calculate the necessary intake is between 0.8 - 1.2 g of protein per kg body weight. However, intense training may require an intake of up to 2.0 g/kg body weight, so always consult your clinician on this.
Timing of Carbohydrate Consumption: Time your carbohydrate intake around your workouts. Consuming carbohydrates before and after exercise can help optimize glycogen replenishment and enhance insulin sensitivity. Saving carbohydrates until later if the day if your insulin is high can help prevent elevated baseline levels all day, and result in better long-term insulin responses.
Regular Exercise: Also a given, but here's your reminder to engage in regular resistance training exercises that target major muscle groups. Resistance training has been shown to improve insulin sensitivity and promote muscle growth. Incorporating cardiovascular exercise into your routine can also have positive effects on insulin sensitivity. Optimal types and quantities of exercise vary based on the individual, but a general guideline for adults is to engage in at least 150 minutes of moderate-intensity aerobic exercise (walking, biking, swimming, dancing) per week, or 75 minutes of vigorous-intensity exercise (running, high paced cycling, HIIT) spread across the week.
Sleep and Stress Management: This is where I see most people struggle. Prioritizing sufficient sleep and effective stress management is a must. Lack of sleep and chronic stress can negatively impact insulin sensitivity by driving more cortisol and gluconeogenesis (increasing blood sugar from storage). Aim for 7 to 8 hours of quality sleep and adopt stress-reduction techniques such as meditation or engaging in activities you enjoy.
Regular Medical Check-ups: Regularly monitor your blood sugar and insulin levels by consulting with a healthcare professional. They can provide guidance on managing insulin levels and assess any underlying health conditions that may affect insulin sensitivity.
It's important to note that individual requirements may vary, and consulting with a healthcare professional who can provide personalized guidance and support in optimizing insulin levels for muscle mass growth is recommended.
Finding the best approach to overall fitness can be challenging with so much information (and misinformation) everywhere, so speaking with a professional can help you find the right combination of diet and exercise to reach your fitness and overall health goals.