What is the difference between strength and endurance? Simply put strength is the ability to generate force in the presence of resistance (moving something heavy) and endurance is the ability to perform prolonged, less forceful, contractions over time. Type 1 slow twitch muscle fibers are associated with endurance and type 2 fast twitch muscular fibers are associated with strength. We have the power to influence the abundance of each fiber, and this is depends on the type of exercise we perform.
Examples of strengthening exercises are performing heavy bench press, back squats, or dead lifts for 5-8 repetitions. Examples of endurance exercise include running, swimming, jogging, or performing any exercise (bench, squats, dead lifts) with a high frequency (10 or more repetitions).
As with anything else, it’s important to realize that the power to change your muscle composition is yours! Yay! That’s empowering isn’t it?! So first off, why do we need each type of fiber, and what fiber is the most important?
Endurance enables us to tolerate life’s activities such as caring for kids, walking to and from parking lots, and standing all day. Endurance training also improves our cardiovascular health and endurance. Muscle strength, on the other hand, enables us to lift and move objects. Here’s the problem: Many people focus only on endurance type training such as treadmill, biking, swimming, running, elliptical or light, high repetitive strength work, which is actually endurance training since the contraction becomes prolonged over time as oppose to quick and forceful for low repetitions as in strength building.
Here’s the kicker: Endurance training does not significantly increase strength; however, strength training can significantly improve endurance. For example–If you want to run a 5K or a marathon continuous running will improve your ability to run but it will not improve your ability to lift and move heavy objects. I have evaluated many endurance athletes that exhibit strength deficits. They are typically shocked at this revelation because they exercise every day. When I question the type of exercise it is endurance training or light, repetitive strength training. This type of exercise does not correlate to strength improvements. With prolonged endurance training type 2 fibers will convert to type 1. Conversely, prolonged strength training will convert muscle fibers to type 2.
There are two categories of type 2 fibers. One related to producing a quick force, and one relating to repeating the reproduction of that force over time (endurance). With prolonged strength training, muscle fibers are converted to type 2 but because of the two categories of type 2 fibers (one for strength and one for endurance) the end result is improvements of strength as well as endurance. This is why strength training correlates to the ability to perform endurance activities more efficiently.
Strength training also multiplies the capillary presence within the muscle promoting vascularization. With improved vascularization oxygen and nutrients are better transported to and utilized by the muscle.
Muscle pumping action also improves hormonal release and utilization, which can have profound effects on chronic illness such as diabetes and chronic pain syndromes. Strength building also works to prevent chronic overuse syndromes through muscular balance across multiple axis, reduces chronic pain via hormonal release, and improve vascularization and oxygenation.
Of course you will never run a 5K if you don’t practice running but the take home message is that strength training is essential to meet any type of aerobic, endurance, wellness, or fitness goal.
Life is all about balance, and both strength and endurance training have profound health benefits. The additional caveat is flexibility. Flexibility plays a key role in health as well. The total package would be defined as strength, endurance, AND flexibility. With this, please know that a weekly practice (even if just one day a week) focused at flexibility is also essential.
We are multi-dimensional beings requiring a multi-dimensional approach to health, wellness, and physical performance.