In the world of health and fitness, there are several key metrics used to assess and track an individual’s overall well-being. One of the most informative indicators of metabolic health is metabolic age. As a fitness professional, especially if you’re affiliated with the American Sports and Fitness Association (ASFA), understanding and utilizing metabolic age can play a pivotal role in helping clients achieve better health outcomes and tailor fitness strategies.
Relative metabolic age is a comparative measure calculated by subtracting a person's chronological age from their metabolic age, which is derived from their Basal Metabolic Rate (BMR).
In this comprehensive guide, we will dive into what metabolic age is, how it is calculated, its implications for health, and how you, as a fitness professional, can help clients improve their metabolic age through effective lifestyle changes and personalized training programs.
What is Metabolic Age?
Metabolic age is a measure that compares an individual’s Basal Metabolic Rate** (BMR)** to the average BMR of people within the same age group. Essentially, it provides insight into whether your client’s metabolism is working at an expected rate for their chronological age or if it is functioning faster or slower.
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Metabolism refers to the process by which the body converts food into energy. The faster an individual’s metabolism, the more efficiently their body burns calories, even at rest. Resting energy expenditure (REE) is the number of calories burned while the body is at rest and is closely related to BMR and overall metabolic health.
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Metabolic age indicates how your client’s metabolic health stacks up against the typical metabolic function of people of the same age.
For example:
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If a client’s metabolic age is younger than their chronological age, it means they have a higher metabolic rate and are burning more calories at rest compared to others their age.
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If their metabolic age is older than their actual age, it suggests that their metabolism is slower, potentially due to factors such as excess body fat, decreased muscle mass, or poor lifestyle habits.
By tracking metabolic age, fitness professionals can get a clearer picture of their clients’ overall metabolic health and guide them in improving it.
How is Metabolic Age Calculated?
Calculating metabolic age typically revolves around determining a person’s Basal Metabolic Rate (BMR) and comparing it to the average BMR values for their chronological age group. There are several methods to assess metabolic age, but the most common is based on BMR.
Energy expenditure is the total amount of energy used by the body for various functions, including resting metabolic rate, thermic effect of food, and physical activity.
Step-by-Step Process to Calculate Metabolic Age:
Step 1: Determine Basal Metabolic Rate (BMR)
BMR is the number of calories the body needs to perform basic life-sustaining functions, such as breathing, circulation, and digestion, while at rest. BMR can be calculated using several formulas, with the Mifflin-St Jeor Equation being one of the most accurate:
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For men:
BMR=10×weight (kg)+6.25×height (cm)−5×age (years)+5\text{BMR} = 10 \times \text{weight (kg)} + 6.25 \times \text{height (cm)} - 5 \times \text{age (years)} + 5 -
For women:
BMR=10×weight (kg)+6.25×height (cm)−5×age (years)−161\text{BMR} = 10 \times \text{weight (kg)} + 6.25 \times \text{height (cm)} - 5 \times \text{age (years)} - 161
Example Calculation:
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A 35-year-old woman weighing 70 kg and standing 165 cm tall would have a BMR of:
10×70+6.25×165−5×35−161=1450 calories/day10 \times 70 + 6.25 \times 165 - 5 \times 35 - 161 = 1450 \text{ calories/day}
Step 2: Compare BMR to Average BMR for Age Group
Once the BMR is determined, it's compared to the average BMR values of people in the same chronological age group. Various tools, charts, and even body composition scales (such as those using bioelectrical impedance analysis or DEXA scans) can assist in this comparison. If the individual's BMR is higher than the average BMR of their peers, they likely have a younger metabolic age. If it's lower, they may have an older metabolic age.
Step 3: Estimate Metabolic Age
The metabolic age is then estimated based on where the individual's BMR falls in comparison to others in their age group:
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Higher BMR: Indicates a younger metabolic age.
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Lower BMR: Indicates an older metabolic age.
Some body composition devices can directly calculate metabolic age by taking into account factors such as body fat percentage, muscle mass, visceral fat, and water retention.
Implications of Metabolic Age for Health and Fitness
Understanding a client’s metabolic age can provide fitness professionals with deeper insights into their overall metabolic health, helping to fine-tune fitness strategies and lifestyle recommendations.
A younger relative metabolic age indicates better health and fitness. Achieving a lower metabolic age can be accomplished through dietary changes, regular exercise, and lifestyle adjustments.
Implications of a Younger Metabolic Age:
A younger metabolic age is generally associated with:
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Efficient Calorie Burning: The body is better at burning calories even at rest, which can contribute to easier weight management.
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Increased Muscle Mass: Lean muscle tissue is metabolically active, meaning it burns more calories than fat even when the body is at rest. A younger metabolic age often correlates with higher muscle mass.
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Enhanced Energy Levels: Clients with a younger metabolic age may experience higher energy levels and improved physical performance.
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Improved Cardiovascular Health: A more efficient metabolism supports overall health, potentially reducing the risk of metabolic diseases such as diabetes or heart disease.
Implications of an Older Metabolic Age:
An older metabolic age may indicate the following:
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Reduced Metabolic Efficiency: Clients may find it harder to lose weight or maintain their current weight.
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Muscle Loss: Age-related muscle loss, or sarcopenia, is often associated with a slower metabolism, which can lead to an increase in body fat and a decline in overall strength.
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Lower Energy Levels: With a slower metabolism, clients may feel fatigued more easily and struggle to maintain energy throughout the day.
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Increased Risk of Metabolic Diseases: A slower metabolism is often linked to higher body fat levels, insulin resistance, and a higher risk of conditions such as type 2 diabetes, hypertension, and cardiovascular disease.
By understanding metabolic age, fitness professionals can assess how well a client's body is functioning metabolically and develop strategies to improve their metabolic health.
Factors Affecting Metabolic Age
A variety of factors can influence an individual’s metabolic age, including their lifestyle, fitness level, diet, and even genetic predispositions. As a fitness professional, you should consider these factors when creating customized plans to help clients improve their metabolic age. Clients can improve metabolic age through lifestyle changes such as adopting a healthy diet, engaging in regular exercise, and implementing a metabolic repair program.
a. Muscle Mass
Muscle is metabolically active tissue that burns more calories than fat, even at rest. Individuals with higher lean muscle mass typically have a more efficient metabolism and therefore a younger metabolic age. This is why resistance training and strength-building exercises are essential for maintaining or improving metabolic function.
b. Body Fat Percentage
Higher body fat percentages, especially visceral fat (fat stored around the organs), are associated with a slower metabolism. A high level of body fat can lead to metabolic inefficiencies, making it harder to maintain a healthy metabolic age.
c. Physical Activity Levels
Regular exercise, particularly strength training and cardiovascular exercise, plays a significant role in maintaining a healthy metabolism. Exercise boosts muscle mass, promotes fat loss, and improves overall metabolic function. Sedentary lifestyles are one of the main contributors to a higher (older) metabolic age.
d. Diet and Nutrition
Nutrition plays a critical role in determining metabolic health. Diets high in processed foods, sugars, and unhealthy fats can slow down metabolism, while balanced, nutrient-rich diets that include lean proteins, whole grains, fruits, and vegetables can improve it. Protein intake, in particular, is important for maintaining muscle mass and promoting metabolic efficiency.
e. Hydration
Water is essential for all metabolic processes, including digestion and calorie burning. Dehydration can reduce metabolic rate and make it more difficult for the body to function efficiently.
f. Sleep and Stress Levels
Both sleep and stress affect hormonal balance, particularly hormones like cortisol and insulin, which play a role in metabolism. Poor sleep and high stress levels can negatively impact metabolic health, leading to a slower metabolism and an increase in body fat.
g. Age and Genetics
As individuals age, muscle mass naturally decreases, and metabolic rate slows down. However, some people may experience a slower metabolism due to genetic factors, making it even more important to focus on lifestyle adjustments to mitigate age-related metabolic decline.
How to Help Clients Improve Their Metabolic Age
Improving metabolic age requires a multi-faceted approach that combines exercise, nutrition, and healthy lifestyle changes. As a fitness professional, here's how you can guide your clients to improve their metabolic age and overall health:
a. Strength Training
Encourage clients to engage in regular strength training exercises, such as weightlifting, bodyweight exercises (e.g., squats, push-ups), and resistance band workouts. Strength training helps build and preserve lean muscle mass, which is key to maintaining or increasing metabolism. Muscle burns more calories than fat, contributing to a younger metabolic age.
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Tip: Aim for at least two strength training sessions per week, focusing on major muscle groups.
b. Cardiovascular Exercise
Incorporating cardiovascular activities, such as running, cycling, swimming, or HIIT (High-Intensity Interval Training), helps burn calories, reduce body fat, and improve heart health. Cardio also boosts the efficiency of the cardiovascular system, supporting overall metabolic health.
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Tip: Encourage clients to include both steady-state cardio and interval training in their routines to maximize calorie burn and metabolic benefits.
c. Balanced Nutrition
Help clients create a well-balanced nutrition plan that supports muscle growth, fat loss, and metabolic efficiency. Focus on lean proteins (which help preserve muscle mass), complex carbohydrates (which provide energy), and healthy fats (which support overall health). Avoid excessive sugar and processed foods.
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Tip: Ensure that clients are consuming enough calories to support their energy needs, but not so much that they accumulate excess body fat.
d. Hydration
Remind clients to drink plenty of water throughout the day to keep their metabolism functioning at its best. Staying hydrated aids digestion, supports muscle function, and improves calorie burning.
e. Sleep and Stress Management
Stress and sleep deprivation can wreak havoc on the metabolism. Encourage clients to prioritize 7-9 hours of sleep per night and practice stress-reducing techniques such as mindfulness, meditation, or yoga. These strategies can help regulate hormones that affect metabolism, such as cortisol and insulin.
f. Active Lifestyle
Aside from structured workouts, promote non-exercise physical activity. Encourage clients to incorporate movement into their daily lives through activities such as walking, taking stairs, and standing more often throughout the day.
Conclusion
Metabolic age is a valuable indicator of a person's metabolic health and overall well-being. By understanding how to calculate metabolic age and the factors that influence it, fitness professionals can provide clients with a personalized approach to improving their metabolic function. Through strength training, cardiovascular exercise, proper nutrition, and lifestyle changes, you can help clients achieve a younger metabolic age, which contributes to better weight management, enhanced energy, and long-term health benefits.
With a holistic approach to fitness, clients can improve not only their metabolic age but also their overall health and quality of life. Always remind clients to consult healthcare professionals when necessary, especially if they have underlying medical conditions that may affect their metabolic health.
