Anabolic resistance is characterized by the body's reduced capacity to react to anabolic stimuli, like those from dietary protein or resistance exercise, resulting in a decreased muscle protein synthesis response.

This concept is frequently discussed in the context of aging, particularly among older individuals who commonly encounter an attenuated muscle protein synthesis response even when consuming sufficient protein and engaging in exercise.

Here are some factors that contribute to anabolic resistance:

• Aging: Anabolic resistance is commonly associated with aging. As people get older, there is a natural decline in the sensitivity of muscle tissues to anabolic signals, including protein intake and exercise. This can result in reduced muscle protein synthesis and a gradual loss of muscle mass.
• Insulin Resistance: Insulin resistance, which is often associated with metabolic disorders like type 2 diabetes, can impact the body’s ability to utilize nutrients, including amino acids, effectively for muscle protein synthesis.
• Inflammation: Chronic inflammation, often seen in conditions like obesity, can interfere with muscle protein synthesis by disrupting the signaling pathways involved in muscle growth.
• Hormonal Changes: Hormonal changes that occur with aging, such as decreases in testosterone and growth hormone levels, can contribute to anabolic resistance.
• Mitochondrial Dysfunction: Impaired mitochondrial function, which occurs with aging and certain health conditions, can affect the efficiency of energy production in muscle cells. This can limit their capacity for growth and repair.
• Altered Amino Acid Availability: Aging and some health conditions can lead to altered amino acid availability in the bloodstream. This affects the body’s ability to supply muscles with the necessary building blocks for protein synthesis.
• Oxidative Stress: Elevated oxidative stress can disrupt cellular processes and signaling pathways, potentially impairing muscle protein synthesis.
• Physical Inactivity: Leading a sedentary lifestyle can contribute to anabolic resistance by reducing the body’s response to muscle-building stimuli like exercise.
• Nutrient Deficiency: Inadequate intake of essential nutrients, including protein and certain micronutrients, can exacerbate the issue of anabolic resistance.
• Genetic Factors: Genetic variations can influence an individual’s susceptibility to anabolic resistance, affecting their muscle protein synthesis response to various stimuli.
• Medications and Chronic Illness: Some medications and chronic illnesses contribute to anabolic resistance by affecting nutrient absorption, utilization, and signaling pathways.

Recognizing anabolic resistance typically involves assessing several factors and considering their effects on muscle protein synthesis.

While there isn’t a single definitive test for anabolic resistance, here are some signs and steps that can help individuals determine if they might be experiencing it:

• Muscle Loss: Noticeable muscle loss or difficulty in building muscle despite consistent exercise and protein intake could indicate potential anabolic resistance.
• Limited Progress: If you’ve been following a structured resistance training and nutrition plan but are not seeing the expected gains in muscle mass and strength, anabolic resistance might be a factor.
• Aging: Anabolic resistance is often associated with aging. If you’re an older adult and noticing challenges in maintaining or building muscle mass, it’s worth considering the possibility of anabolic resistance.

• Low Responsiveness: You might have anabolic resistance if your muscle protein synthesis response to protein-rich meals or resistance exercise seems to be lower than expected.
• Recovery Issues: Slow recovery after exercise, especially muscle soreness that persists longer than usual, could be indicative of compromised muscle protein synthesis.
• Chronic Conditions: If you have conditions like diabetes, obesity, or chronic inflammatory disorders, these can contribute to anabolic resistance. Monitoring muscle health in the context of such conditions is important.
• Loss of Strength: Anabolic resistance can lead to reduced muscle function and strength. If you’re experiencing unexplained decreases in strength despite maintaining your fitness routine, it’s worth investigating further.

Addressing anabolic resistance involves a multifaceted approach, including optimizing dietary protein intake, overall nutrition, hormonal balance, engaging in regular resistance exercise, managing inflammation, and addressing any underlying health conditions.

It’s important to develop personalized strategies for combating anabolic resistance and preserving muscle mass, especially in older adults.

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​Here's a another episode in my Protein Series on how Protein needs change with age:​

Aging Gracefully ​ ...The Truth About Protein Needs for Older Adults ​ Read article

Disclaimer

This information is not medical advice. This content and other content on this website is for informational and educational purposes only and is not intended to be a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

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References

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• Bell KE, von Allmen MT, Devries MC, Phillips SM. Muscle Disuse as a Pivotal Problem in Sarcopenia-related Muscle Loss and Dysfunction. J Frailty Aging. 2016;5(1):33-41. doi: 10.14283/jfa.2016.78. PMID: 26980367.
• Murphy CH, Oikawa SY, Phillips SM. Dietary Protein to Maintain Muscle Mass in Aging: A Case for Per-meal Protein Recommendations. J Frailty Aging. 2016;5(1):49-58. doi: 10.14283/jfa.2016.80. PMID: 26980369.

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