9
MIN READ
Achieving peak performance: The benefits of muscular strength testing
Muscle strength is essential for healthy ageing and improved longevity.
Written by
Team Compound
Medically reviewed by
Team Compound
Last updated
April 17, 2024

If you’re embarking on a fitness journey, you’re likely hitting the gym and performing all manner of weighted exercises in the hope of seeing some muscular gains.

While a brief scan of the gym floor will reveal those who enjoy flexing biceps in the mirror or grunting through a series of squats, the truth is that muscle strength is far more significant than aesthetics alone. 

Research suggests that muscular strength is vital for optimal health [1]. Carrying heavy groceries from the store to the car or lifting heavy objects overhead is possible thanks to those muscles that contribute to our upper body endurance. But muscle strength is also essential for healthy ageing and improved longevity, aiding everything from your posture to your sleep quality and mental health.

But how exactly do you test muscular strength to know you’re making progress? Here, we’ll explain everything you need to know about the muscular strength test and how the strength and endurance of muscle groups can be improved. Let's dive in!

Why is muscle strength important?

Muscular strength is the bedrock upon which all your physical functions are built — from opening a jar to lifting objects and maintaining posture. And, while muscular strength might be thought of as the domain of bodybuilders, it's incredibly important for everyone, especially as we age.

A decline in strength can often lead to reduced functional independence in older age, leading to a lower quality of life. So, muscular strength is imperative when it comes to preserving vitality.

Muscle strength refers to the ability of a muscle to contract and produce force in a single effort and is incredibly important for optimal health. After the age of 50, bone loss accelerates while bone formation can no longer outpace bone breakdown [2]. It’s a change that coincides with greater risks of bone fractures and health conditions like osteoporosis.

Studies have shown that resistance training and greater muscle strength can actually prevent bone loss, and in some instances even build bone, making it extremely important for healthy ageing [3].

Other benefits of muscle strength that make it important for overall health include:

Enhanced body composition

Research has shown that strength training has the greatest impact on body composition, helping individuals to build lean muscle mass and decrease fat percentage [4]. 

Reduced risk of falls and injuries

With consistent strength training, the body builds greater single-leg strength, balance, and coordination — all of which can reduce the risk of falling and decrease the risk of injuries to the upper and lower extremities. 

Improved mood and energy levels

Exercise has been proven to boost mood thanks to endorphins, but studies have also shown that resistance training can significantly reduce anxiety, depression, and other negative mood states [5]. It can also boost your energy levels as your cardiovascular system learns to work more efficiently. 

Helps to maintain a healthy weight

Resistance training can help you manage your weight. It can also increase your metabolism as the more muscle you have, the more calories you burn.  

Promotes healthy sleep patterns

Resistance training has been found to improve sleep quality and duration, with a study finding those who did resistance training for a year added an average of 40 minutes of sleep per night [6]. 

Greater mobility and range of motion

Resistance training is known to increase joint range of motion, allowing for greater flexibility and mobility which in turn can improve your quality of life as you age [7]. Those with weaker muscles tend to have a lower range of movement.  

Why is muscular strength testing important?

Now we know why muscular strength is important for everyone, not just athletes, let's look at why testing this strength is imperative. For starters, conducting a muscular strength test allows you to identify significant strength imbalances present in the body, which is helpful for gauging injury risks and vulnerabilities.

Secondly, doing maximal strength training in certain biomechanical movements allows us to estimate what your one rep max for major compound movements, like a squat, is. From here, you can seek guidance for loading on resistance training.

This is why we include physio-guided testing in our Compound program diagnostics. Physios, in general, are underutilised — it's not only about injury, triaging and treatment; injury prevention is incredibly important.

What is Compound, exactly? Well, we're a digital clinic for performance health. Once the exclusive domain of billionaires and Hollywood stars, we're on a mission to make premium concierge care accessible to every man who wants more.

We take a multi-disciplinary approach to health optimisation and preventative care to help men unlock barriers to everyday performance. As part of our program, we pull together a comprehensive diagnostic report pulled from several data sources, including running gait analysis and muscular strength testing.

We also design personalised training programs, with an emphasis on prehab — where generic workouts can sometimes cause harm, an individualised prehab routine can aid in reducing injury risk. More on this later.

How is muscle strength tested?

Muscle strength testing provides useful information about the capability of your muscles to produce force. Using a muscle strength test, you can see any weaknesses or imbalances, which can then provide the basis for a rehabilitation plan or workout program.

In traditional healthcare, it can also be used in the diagnosis, prognosis, and management of any neuromuscular and musculoskeletal disorders. 

There are two main kinds of muscle contraction: isometric, where the contraction is static and results in no change to muscle length, and isotonic, when tension remains the same but the muscle’s length changes.

For isotonic contractions, you may have a shortening of the muscle (concentric contraction) such as the upward movement of a bicep curl, and a lengthening of the muscle (eccentric contraction), which occurs in the downward phase of a bicep curl as the arm straightens. 

Why are these contractions important? Well, during muscle strength testing and muscular endurance tests, your muscles will be tested in three key areas:

  • Isotonic: Muscles will be placed under constant external resistance in the form of free weights or a resistance machine. This primarily tests the strength of muscle groups rather than individual muscles, as techniques used tend to be the one-repetition maximum (1-RM), which requires you to lift a maximum weight against gravity through an entire range of motion. 
  • Isokinetic: While the resistance will vary depending on the individual, isokinetic testing involves muscles undergoing a constant speed of angular motion during contraction. The equipment used is an isokinetic dynamometer which allows for isolation of specific joints.  
  • Isometric: Muscles will generate force against an immovable resistance, with muscle length remaining constant throughout the test. Examples of isometric testing include manual muscle testing and handheld dynamometry, both of which are inexpensive and easily accessible. 

Now that you know the contractions that can be observed to assess muscle groups, you can understand how muscle strength testing is done. The main form is manual muscle testing (MMT) and dynamometric testing.

The latter requires the use of handheld devices known as dynamometers which are positioned against the muscle to evaluate how much tension a muscle can exert during contraction without motion. Though accurate, this form of testing can be relatively difficult due to the costs associated with the devices.

The most commonly accepted method of muscle strength testing is manual muscle testing as it requires no equipment and can be measured on a scale that helps to evaluate weakness in a specific muscle or muscle group and pinpoint areas of weakness, limited mobility, and imbalance.

What is the muscle strength grading scale?

When assessing the function and strength of individual muscles or muscle groups through manual muscle testing, a grading scale is used.

There is a range available, from the Kendall Muscle Testing Scale to the Daniels and Worthinghmans Manual Muscle Testing Scale. However, the most commonly used grading scale is that of the Medical Research Council (MRC) Scale, otherwise known as the Oxford Scale. 

As the institution that established the standard for muscle strength testing, the MRC Scale uses a grading system from 0 to 5. These levels relate to the following observations in performance and muscle strength. 

  • Grade 0: Unable to activate the muscle, no movement or noticeable contraction is evident. This may be a result of injury or medical condition such as muscle paralysis that occurs in the vent of a stroke or spinal cord injury. Pain may also be present, preventing the muscle from contracting. 
  • Grade 1: You can activate the muscle but no movement occurs in the limb, making the contraction so minor it may only be detected with physical touch. For this category score, the muscle is still not strong enough to lift the body part against gravity or move it in a gravity-reduced position. 
  • Grade 2: The muscle can contract, but it’s still unable to move the body part fully against gravity. Only when gravity is eliminated can movement over a full range of motion occur. 
  • Grade 3: Without resistance coming from the examiner, the muscle can contract and move the body part through its full range of motion against the force of gravity. However, as soon as resistance is applied, the muscle is unable to maintain the contraction. 
  • Grade 4: The muscle can contract and move through the full range of motion with moderate resistance being applied by the examiner. Only when maximum resistance is applied does the muscle become unable to maintain the contraction. 
  • Grade 5: The muscle will be functioning normally with a return to full strength. You can move through a full range of motion with the muscle maintaining its contraction while maximum resistance is applied. 

With this grading scale, you can be confident that the criteria outlined above yield reliable results even when manually testing muscle strength using your own observations or those of a physical therapist or trainer. 

Where to undergo a muscle strength test

You can undergo a muscle strength test at a range of locations, but most notably it’s offered by physical therapists, exercise physiologists, personal trainers, and certain health practitioners. 

Because manual muscle testing requires familiarity with the MRC Scale, measuring muscle strength should be done by a trained professional or physical therapist.

As well as helping perform the testing, their observations will allow for accurate grading that can then be used to identify muscle weakness, areas of improvement, or the creation of a workout program to address your rehabilitation and muscular strength needs. 

How to improve muscular strength and endurance

By first evaluating muscle strength, you can then create a workout plan and fitness program to build upon the foundation of strength you already have. It’s also important to test your current strength first as this can help to avoid injuries as you look to increase your training load.

Where muscular strength refers to the muscle's ability to produce maximum force, muscular endurance relates to the ability of a muscle to sustain repeated contractions against resistance for a period of time.

These key differences are important to keep in mind as training needs to be tailored to each distinct approach. For example, to improve muscular strength, you need to increase loading and volume which can be done by using heavier weights and fewer repetitions.

For muscular endurance, more repetitions and lighter weight are needed to see improvements, while exercises like long-distance running, cycling, and swimming can also increase muscular endurance. Various tests can also be done to measure muscular endurance, which can result in valid and reproducible results. These tests should be performed on the upper and lower body.

A key factor when looking to improve muscular strength and endurance is the FITT principle, which refers to the frequency, intensity, time, and type of your workouts. 

Frequency

Consider the number of sessions you complete in a week. To see improvements, you need to consistently load your muscles. It’s recommended that you do strength training at least two days a week to see results. 

Intensity

When it comes to the amount of weight used per repetition, this will vary depending on the individual and your current baseline of strength. For muscular strength improvements, your training needs to involve one to 10 repetitions of 60 to 80% of your maximum effort (1-RM) per set, and two to four sets completed in total. 

Time

While quality over quantity is always important, resistance training should range from 30 to 60 minutes. This allows you to adequately rest between sets so you can build greater strength and endurance. 

Type

Improving muscular strength and endurance isn’t just about hitting the gym to repeat the same exercises again and again. Your body needs variation as it adapts to training load and volume, and changing the type of workout will ensure you stay engaged and motivated. 

Whether you’re looking to improve your body composition with increased lean muscle or simply want to improve your muscle strength to support optimal performance, a muscle strength assessment can provide a baseline to then track your progress.

With its comprehensive diagnostic reporting, Compound's program utilises the latest science and technology to ensure you have the tools required to unlock your best self. With the guidance of a physiotherapist, we can help implement strategies that promote both immediate and long-term benefits.

Physiotherapists tailor exercise programs to improve mobility, strength, and coordination, which are all vital for injury prevention. This allows you to sustain a high level of activity — including setting an audacious fitness goal with our team of dedicated healthcare professionals and expert specialists — without the fear of sidelining injuries.

If you’re embarking on a fitness journey, you’re likely hitting the gym and performing all manner of weighted exercises in the hope of seeing some muscular gains.

While a brief scan of the gym floor will reveal those who enjoy flexing biceps in the mirror or grunting through a series of squats, the truth is that muscle strength is far more significant than aesthetics alone. 

Research suggests that muscular strength is vital for optimal health [1]. Carrying heavy groceries from the store to the car or lifting heavy objects overhead is possible thanks to those muscles that contribute to our upper body endurance. But muscle strength is also essential for healthy ageing and improved longevity, aiding everything from your posture to your sleep quality and mental health.

But how exactly do you test muscular strength to know you’re making progress? Here, we’ll explain everything you need to know about the muscular strength test and how the strength and endurance of muscle groups can be improved. Let's dive in!

Why is muscle strength important?

Muscular strength is the bedrock upon which all your physical functions are built — from opening a jar to lifting objects and maintaining posture. And, while muscular strength might be thought of as the domain of bodybuilders, it's incredibly important for everyone, especially as we age.

A decline in strength can often lead to reduced functional independence in older age, leading to a lower quality of life. So, muscular strength is imperative when it comes to preserving vitality.

Muscle strength refers to the ability of a muscle to contract and produce force in a single effort and is incredibly important for optimal health. After the age of 50, bone loss accelerates while bone formation can no longer outpace bone breakdown [2]. It’s a change that coincides with greater risks of bone fractures and health conditions like osteoporosis.

Studies have shown that resistance training and greater muscle strength can actually prevent bone loss, and in some instances even build bone, making it extremely important for healthy ageing [3].

Other benefits of muscle strength that make it important for overall health include:

Enhanced body composition

Research has shown that strength training has the greatest impact on body composition, helping individuals to build lean muscle mass and decrease fat percentage [4]. 

Reduced risk of falls and injuries

With consistent strength training, the body builds greater single-leg strength, balance, and coordination — all of which can reduce the risk of falling and decrease the risk of injuries to the upper and lower extremities. 

Improved mood and energy levels

Exercise has been proven to boost mood thanks to endorphins, but studies have also shown that resistance training can significantly reduce anxiety, depression, and other negative mood states [5]. It can also boost your energy levels as your cardiovascular system learns to work more efficiently. 

Helps to maintain a healthy weight

Resistance training can help you manage your weight. It can also increase your metabolism as the more muscle you have, the more calories you burn.  

Promotes healthy sleep patterns

Resistance training has been found to improve sleep quality and duration, with a study finding those who did resistance training for a year added an average of 40 minutes of sleep per night [6]. 

Greater mobility and range of motion

Resistance training is known to increase joint range of motion, allowing for greater flexibility and mobility which in turn can improve your quality of life as you age [7]. Those with weaker muscles tend to have a lower range of movement.  

Why is muscular strength testing important?

Now we know why muscular strength is important for everyone, not just athletes, let's look at why testing this strength is imperative. For starters, conducting a muscular strength test allows you to identify significant strength imbalances present in the body, which is helpful for gauging injury risks and vulnerabilities.

Secondly, doing maximal strength training in certain biomechanical movements allows us to estimate what your one rep max for major compound movements, like a squat, is. From here, you can seek guidance for loading on resistance training.

This is why we include physio-guided testing in our Compound program diagnostics. Physios, in general, are underutilised — it's not only about injury, triaging and treatment; injury prevention is incredibly important.

What is Compound, exactly? Well, we're a digital clinic for performance health. Once the exclusive domain of billionaires and Hollywood stars, we're on a mission to make premium concierge care accessible to every man who wants more.

We take a multi-disciplinary approach to health optimisation and preventative care to help men unlock barriers to everyday performance. As part of our program, we pull together a comprehensive diagnostic report pulled from several data sources, including running gait analysis and muscular strength testing.

We also design personalised training programs, with an emphasis on prehab — where generic workouts can sometimes cause harm, an individualised prehab routine can aid in reducing injury risk. More on this later.

How is muscle strength tested?

Muscle strength testing provides useful information about the capability of your muscles to produce force. Using a muscle strength test, you can see any weaknesses or imbalances, which can then provide the basis for a rehabilitation plan or workout program.

In traditional healthcare, it can also be used in the diagnosis, prognosis, and management of any neuromuscular and musculoskeletal disorders. 

There are two main kinds of muscle contraction: isometric, where the contraction is static and results in no change to muscle length, and isotonic, when tension remains the same but the muscle’s length changes.

For isotonic contractions, you may have a shortening of the muscle (concentric contraction) such as the upward movement of a bicep curl, and a lengthening of the muscle (eccentric contraction), which occurs in the downward phase of a bicep curl as the arm straightens. 

Why are these contractions important? Well, during muscle strength testing and muscular endurance tests, your muscles will be tested in three key areas:

  • Isotonic: Muscles will be placed under constant external resistance in the form of free weights or a resistance machine. This primarily tests the strength of muscle groups rather than individual muscles, as techniques used tend to be the one-repetition maximum (1-RM), which requires you to lift a maximum weight against gravity through an entire range of motion. 
  • Isokinetic: While the resistance will vary depending on the individual, isokinetic testing involves muscles undergoing a constant speed of angular motion during contraction. The equipment used is an isokinetic dynamometer which allows for isolation of specific joints.  
  • Isometric: Muscles will generate force against an immovable resistance, with muscle length remaining constant throughout the test. Examples of isometric testing include manual muscle testing and handheld dynamometry, both of which are inexpensive and easily accessible. 

Now that you know the contractions that can be observed to assess muscle groups, you can understand how muscle strength testing is done. The main form is manual muscle testing (MMT) and dynamometric testing.

The latter requires the use of handheld devices known as dynamometers which are positioned against the muscle to evaluate how much tension a muscle can exert during contraction without motion. Though accurate, this form of testing can be relatively difficult due to the costs associated with the devices.

The most commonly accepted method of muscle strength testing is manual muscle testing as it requires no equipment and can be measured on a scale that helps to evaluate weakness in a specific muscle or muscle group and pinpoint areas of weakness, limited mobility, and imbalance.

What is the muscle strength grading scale?

When assessing the function and strength of individual muscles or muscle groups through manual muscle testing, a grading scale is used.

There is a range available, from the Kendall Muscle Testing Scale to the Daniels and Worthinghmans Manual Muscle Testing Scale. However, the most commonly used grading scale is that of the Medical Research Council (MRC) Scale, otherwise known as the Oxford Scale. 

As the institution that established the standard for muscle strength testing, the MRC Scale uses a grading system from 0 to 5. These levels relate to the following observations in performance and muscle strength. 

  • Grade 0: Unable to activate the muscle, no movement or noticeable contraction is evident. This may be a result of injury or medical condition such as muscle paralysis that occurs in the vent of a stroke or spinal cord injury. Pain may also be present, preventing the muscle from contracting. 
  • Grade 1: You can activate the muscle but no movement occurs in the limb, making the contraction so minor it may only be detected with physical touch. For this category score, the muscle is still not strong enough to lift the body part against gravity or move it in a gravity-reduced position. 
  • Grade 2: The muscle can contract, but it’s still unable to move the body part fully against gravity. Only when gravity is eliminated can movement over a full range of motion occur. 
  • Grade 3: Without resistance coming from the examiner, the muscle can contract and move the body part through its full range of motion against the force of gravity. However, as soon as resistance is applied, the muscle is unable to maintain the contraction. 
  • Grade 4: The muscle can contract and move through the full range of motion with moderate resistance being applied by the examiner. Only when maximum resistance is applied does the muscle become unable to maintain the contraction. 
  • Grade 5: The muscle will be functioning normally with a return to full strength. You can move through a full range of motion with the muscle maintaining its contraction while maximum resistance is applied. 

With this grading scale, you can be confident that the criteria outlined above yield reliable results even when manually testing muscle strength using your own observations or those of a physical therapist or trainer. 

Where to undergo a muscle strength test

You can undergo a muscle strength test at a range of locations, but most notably it’s offered by physical therapists, exercise physiologists, personal trainers, and certain health practitioners. 

Because manual muscle testing requires familiarity with the MRC Scale, measuring muscle strength should be done by a trained professional or physical therapist.

As well as helping perform the testing, their observations will allow for accurate grading that can then be used to identify muscle weakness, areas of improvement, or the creation of a workout program to address your rehabilitation and muscular strength needs. 

How to improve muscular strength and endurance

By first evaluating muscle strength, you can then create a workout plan and fitness program to build upon the foundation of strength you already have. It’s also important to test your current strength first as this can help to avoid injuries as you look to increase your training load.

Where muscular strength refers to the muscle's ability to produce maximum force, muscular endurance relates to the ability of a muscle to sustain repeated contractions against resistance for a period of time.

These key differences are important to keep in mind as training needs to be tailored to each distinct approach. For example, to improve muscular strength, you need to increase loading and volume which can be done by using heavier weights and fewer repetitions.

For muscular endurance, more repetitions and lighter weight are needed to see improvements, while exercises like long-distance running, cycling, and swimming can also increase muscular endurance. Various tests can also be done to measure muscular endurance, which can result in valid and reproducible results. These tests should be performed on the upper and lower body.

A key factor when looking to improve muscular strength and endurance is the FITT principle, which refers to the frequency, intensity, time, and type of your workouts. 

Frequency

Consider the number of sessions you complete in a week. To see improvements, you need to consistently load your muscles. It’s recommended that you do strength training at least two days a week to see results. 

Intensity

When it comes to the amount of weight used per repetition, this will vary depending on the individual and your current baseline of strength. For muscular strength improvements, your training needs to involve one to 10 repetitions of 60 to 80% of your maximum effort (1-RM) per set, and two to four sets completed in total. 

Time

While quality over quantity is always important, resistance training should range from 30 to 60 minutes. This allows you to adequately rest between sets so you can build greater strength and endurance. 

Type

Improving muscular strength and endurance isn’t just about hitting the gym to repeat the same exercises again and again. Your body needs variation as it adapts to training load and volume, and changing the type of workout will ensure you stay engaged and motivated. 

Whether you’re looking to improve your body composition with increased lean muscle or simply want to improve your muscle strength to support optimal performance, a muscle strength assessment can provide a baseline to then track your progress.

With its comprehensive diagnostic reporting, Compound's program utilises the latest science and technology to ensure you have the tools required to unlock your best self. With the guidance of a physiotherapist, we can help implement strategies that promote both immediate and long-term benefits.

Physiotherapists tailor exercise programs to improve mobility, strength, and coordination, which are all vital for injury prevention. This allows you to sustain a high level of activity — including setting an audacious fitness goal with our team of dedicated healthcare professionals and expert specialists — without the fear of sidelining injuries.

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