Did you know that how you’re training your muscles matters? It’s because our bodies essentially have two types of muscle fibers that are called upon for different purposes. These are described as muscular endurance, and muscular strength. And both are essential to focus on in your exercise program.
In this article, I’ll explain the difference between strength and endurance, and why they’re equally important. I’ll also share some ideas to help you mix the two into your workout schedule.
Strength vs Endurance
Muscle strength is about how much force a muscle can generate in a single, maximal effort – think of an Olympic weightlifter pressing 1,000 pounds overhead. Where muscle strength is about force production, muscle endurance, on the other hand, is about time – meaning for how long a muscle can continue to produce force.
One illustration of muscle strength versus endurance is with running. A 100-meter sprint is all pure muscle strength; whereas running a 26.2-mile marathon is about muscular endurance. But not everyone’s a runner, so read on to learn about the importance of both in everyday life.
While endurance is all about how long a muscle can perform, muscular strength is about how hard it can perform. We need muscular strength to lift a heavy box, put a case of water in the trunk, or carry a child without getting hurt.
Muscle strength is produced by one of our two main types of muscle fibers – called “fast-twitch” or Type II fibers. These muscle fibers use hardly any oxygen (aka anaerobic) and therefore generate power much faster. But they’re more easily fatigued. In fact, they’re only good for up to about 15 to 30 seconds before they need a rest to replenish. Improving muscular strength comes from creating more muscle fibers, primarily through resistance training. This has a number of health benefits. Not only will resistance training give you a stronger body, it can also counter bone loss, help prevent injury, and potentially reduce all-cause and cancer-linked mortality, according to research.
And because muscle tissue is metabolically active the more muscles you have, the more calories your body burns at rest – thereby increasing your metabolic rate.
Here are just a few exercises to try. For most people, dumbbells or kettlebells are the best choice for these exercises over barbells or machines [Read: The Myth of Weight Machines]. This is because dumbbells force each side of your body to work independently, whereas machines and barbells allow the stronger side of your body to take over.
- Reverse lunges
- Side lunges
- Pushups or chest presses
- Russian twists
All of these exercises will help make daily activities easier by improving strength, coordination, and balance.
Especially when working with heavier weights, know that quality is more important than quantity. How well you perform the movement is what counts – struggling to get through a set with poor form only leads to injury. This relates not only to the amount of weight you’re using, but how many sets you’re doing as well. Two to three sets of 8 to 12 repetitions is all you need.
Finally, understand that recovery is essential to increasing muscular strength. When you lift heavy weights, you’re actually tearing down your existing muscle fibers. It’s when you rest and recover afterwards that the magic happens. Your body works to repair those broken down fibers, making them stronger than before, and build up more new fibers as well. A good rule of thumb is to rest muscles for 48 hours after heavy resistance training for optimal recovery.
Also Build Muscular Endurance
Muscular endurance is the body’s ability to work for an extended amount of time. The longer you can perform a particular movement – like doing a bicep curl, or riding a bike, or running. Even just sitting up with good posture, or a long walk or hike with good stamina, are tests of muscular endurance.
Where muscular strength comes from “fast-twitch” muscle fibers, muscular endurance comes from the other type of fiber, called “slow-twitch” or Type I. These muscle fibers rely on oxygen to function (aka aerobic). By training your slow-twitch fibers, you’re improving the muscles’ ability to use oxygen efficiently – which in turn helps you perform longer before feeling tired.
So whether you’re playing with your kids or doing yard work, or many other day-to-day activities, you need muscular endurance to get you through it. When you have more muscular endurance, you won’t fatigue as quickly, and you’ll be able to go longer while using less energy.
Improve Your Muscular Endurance
Cardiovascular training that involves weight bearing is considered the best way to improve muscular endurance. Activities like brisk walking, hiking, jogging, cycling, stairclimbing, or aerobics like Zumba all require you to be on your feet and stress your large muscle groups to work more efficiently.
Lifting lighter weights with higher number of repetitions – meaning 15 to 20 or more reps in a single set – can also help build muscular endurance, as well as some forms of body-weight-only strength training. The main idea is to find an activity (or two, or three) that keep you interested and challenged.
But keep in mind that muscular endurance training will not noticeably increase the size of muscle fibers. However, over a long period of time (in typical studies, about 12 weeks or more of consistent training) muscle fibers may thicken somewhat.
Your focus with muscular endurance training should be in developing greater stamina, so you can go longer and stronger with less fatigue.
Incorporate Both in Your Fitness Program
We all need muscular strength and endurance for optimum performance and function in everyday life. So how often should you train for them? First, take into consideration your goals and your current fitness level. If you’re just starting out, or getting back into exercise, start with two days per week of strength-focused workouts, and two to three days of endurance-type activities, all for about 30 to 45 minutes. As you develop more strength and stamina, increase the weights you’re lifting and the level of intensity in your endurance activities. Every four weeks, back off a bit and allow yourself a rest week (what’s known as periodized training – read more about it here.) That will allow your body time to really recover and adapt to the work you’ve put in.