What Is Muscular Endurance, and How Can You Build It Up?

A well-rounded fitness routine should include resistance training, some cardiovascular training, and stretching or mobility work. Add in active recovery and de-stressing activities and you've got a solid fitness plan. It sounds simple in theory, but with all of the specific terminology and unqualified "experts" out there touting conflicting advice on social media, things can start to get confusing.

Muscular endurance is one such specific term that we see personal trainers talk about all the time, but what does it mean? And is your usual strength training workout helping with muscular endurance? To find out more about muscular endurance and the benefits of this form of training, we spoke to certified personal trainers Juliet Root and Kim DiLandro.

What Is Muscular Endurance?

"Muscular endurance is the ability of a muscle to repeatedly perform and exert force against resistance for longer periods," explains Root. So essentially, muscular endurance measures how long you're able to hold a position or complete reps (rather than the amount of weight you're lifting).

"Strength is typically measured in one of three ways: general strength, maximal strength, and strength endurance," says DiLandro. "Whereas the former two methods measure the load (weight), the latter measures in reps/time. Muscle (or strength) endurance is tested by the number of repetitions one can handle under a load for a long duration."

• General Strength: Being able to lift your suitcase into the overhead bin on a plane.
• Maximal Strength: Helping a friend move a couch or lifting a heavy box off the ground.
• Muscular Endurance: Holding a baby for hours or carrying your groceries a long-distance walk home.
  

Types of Muscular Endurance

Muscular endurance is all about sustaining a specific movement that requires your muscles to work. The longer your muscles can perform a task that requires strength, the better your muscular endurance.

"This can include aerobic activities such as running, biking, and swimming or resistance training such as weight lifting and calisthenics. When measuring endurance, we are looking at how many reps you can do of a certain exercise or how long you can sustain aerobic activity," says Root.

Muscular endurance differs from cardiovascular endurance in that cardio endurance specifically relates to the ability of your heart and lungs to provide your body with enough oxygen to fuel your activity. The longer you can perform a cardiovascular activity such as running or swimming, the better your cardiovascular endurance.

Why Is Muscular Endurance Important?

Muscular endurance is critical for increasing your daily energy and making day-to-day activities more manageable. "Chores like raking leaves or shoveling snow are less fatiguing for those with high muscular endurance," says DiLandro. "Take a marathon runner, for example—they will have the cardiovascular endurance to walk a far distance from their car to their hotel, but they may not have the muscular endurance to carry their luggage the entire way. When combined with your standard weight training program, muscular endurance can also help prevent injury," explains DiLandro.

The capability to sustain your body's ability to hold tension is also an essential aspect of muscular endurance and is necessary anytime we exert energy in our life. "Just simply going on a walk, climbing flights of stairs, or squatting down to pick up something requires our cardiovascular and muscular endurance to kick in. To feel more effortless and energized during everyday movements, it is important we support our body's ability to sustain efforts for longer periods," adds Root,

How to Measure Muscular Endurance

"We can measure muscular endurance by testing time under tension with strength movements. For example, how long someone can perform a strength training exercise until their body fatigues, loses form, and has to stop. These tests are great, especially when starting a strength training routine for the first time. You will be able to set goals and see progress as you stay consistent over time with your program," says Root.

You can measure your muscular endurance capabilities inside and out of the gym. "In the gym, it can be measured by the number of reps you can complete under a load (weight) for a long duration. This number may change over time, so it is important to track your progress in various exercises to measure changes over time," says DiLandro.

You can also measure muscular endurance by how challenging daily activities are in everyday life. As you increase your muscle endurance, you may find yourself able to carry all your groceries in one trip or opt to take the stairs without fatigue.

"Measuring muscle endurance is specific to each exercise for each person. Some will have more endurance in lower-body movements like squats, and some will have more endurance in upper body movements like pushups or bicep curls," DiLandro adds.

How to Improve Muscular Endurance

One of the best ways to increase your muscular endurance is to add volume in the form of more sets and reps of specific exercises. (Or more time if it's a static exercise like planks.) You can also improve muscular endurance by changing your training intensity and duration. "This can be done by tracking your progress and focusing on progressive overload during your program," says DiLandro.

You can train with a variety of exercises that target each muscle group to improve overall muscular endurance. "I recommend using free weights as a great way to not only train your endurance but to gain more stability. Improving your stability supports your muscular strength and stamina to perform exercises for longer periods of time," says Root.

For muscular endurance, you want to work in a 12-plus rep range. So, when the goal is to improve your muscular endurance, you can choose to overload your reps (15-20+ reps) or your number of sets (4-5 sets), according to DiLandro.

Try these methods from DiLandro below:

• Stability: Changing to an unstable environment leads to increased training intensity. For example, squats on a Bosu ball require more muscle recruitment to stabilize through the movement, which leads to increased energy expenditure.
• Exercise Selection: Choosing compound exercises like squats and deadlifts that recruit large muscle groups and require multiple muscles working together at once. Or, choosing to superset the same muscle groups like bench press right into push-ups is also an effective strategy to improve muscular endurance.
• Rest Periods: Shortening your rest time between sets gives your muscles less time to recover and work harder to perform at the same intensity with each set.  
• Tempo: Adjust the speed at which you work your sets. Slowing down and focusing on slow eccentrics or time under tension requires the muscle a lot more effort. It cannot rely on the elasticity of quick muscle concentric and eccentric movements (thinking snapping of a rubber band). Conversely, working in quick concentrated (or pulsing) movement does not allow the muscle to fully extend into either the eccentric or concentric phase isolating the muscle to fatigue.

Exercises to Improve Muscular Endurance

Squat Walks

• Stand with your feet slightly wider than your hips, feet parallel.
• Shift your weight into your heels (make sure you can wiggle your toes).
• Do four walks side-to-side. 
• Do 15 reps total. 

Bodyweight Planks

• Get into a plank position with your hips in line with shoulders, feet hips with apart and parallel, elbows in line with shoulders. 
• Pull your belly in and tuck your hips. 
• Hold for 90 seconds (You don’t have to start right off the bat at 90 seconds; you can work your way up to this, says Simeone).
  

Bicycle Sit-Ups

• Lay on your back and lift your knees towards your chest.
• Lift your shoulders off the floor, tuck your chin in, and place your hands behind your head with your elbows wide. 
• Switching legs, pedal your legs, bending one leg while straightening the other. Stop the knee when it is directly over your hip at a 90-degree bend for maximum work. Bring your opposite elbow to the bent knee.
• Go through this for 15 reps.  

Push-Ups

• Start in with your hands directly below your shoulders and your lower body resting on the balls of your feet. 
• Slowly move your body down as close to the ground as you can without touching it.
• Push back up to the starting position.

Sit-Ups

• Lay your back flat onto the mat. 
• Keep your knees bent at 90 degrees. 
• Slowly raise your upper body until you're in a seated position. 
• Slowly lower yourself back down to the mat.

Bodyweight Squats

• Stand with your feet just outside of your hips
• Sit back and down.  
• Go as low as you can with good posture and drive back up to a standing position.

Walking Lunges

• From a standing position, take a big step forward. 
• Drop your back knee just above the ground.
• Drive up to a standing position.
• Switch legs.

The Final Takeaway

Muscular endurance is a vital aspect of physical fitness. It fosters better functional movements in your everyday life, reducing risks of injury and improving your performance in your other training modalities. Endurance exercise is taxing, so make sure you are hydrating, fueling, and resting enough in-between to recover properly.