What is Muscular Endurance?
Muscular endurance can be defined as the ability of a muscle, or a group of muscles, to repeatedly exert a force for an extended period of time. Since this involves repeated action over a period of time, muscular endurance always involves a repeated 'submaximal' force.
An athlete with a high level of muscular endurance will be able to repeat a series of muscular contractions without excessive fatigue. In a sporting sense this allows athletes with a greater muscular endurance, to exert more force for longer periods. This is essential for success in many endurance sports. Allowing these athletes to outperform their competitors.
What sports require muscular endurance?
Muscular endurance is important in any sporting event where the main requirement is to repeatedly contract a muscle, or group of muscles. It’s particularly important to endurance events like endurance running, cycling, swimming, triathlon, cross country skiing, and rowing. But also plays a vital role in many other individual sports (tennis, squash, boxing) as well as team sports (football, hockey, netball and rugby).
Why is muscular endurance important?
The greater the level of muscular endurance the more force a muscle can exert over time. This is key for success in any sport which involves competing for prolonged periods. And, especially in events where the object is to finish in the quickest time. Often finishing time is determined by the amount of work that can be completed during the event. A good example is cycling time trials. In this case, success is often determined by the cyclist who can sustain the most force (power) during the time trial. However, it often makes a big difference in team sports as well.
What factors affect muscular endurance?
A number of factors affect muscular endurance including:
Muscle fibre types (slow and fast twitch muscle fibres)
The percentage of different muscle fibre types can have a significant effect on muscular endurance. Our muscles are made up of two different types of muscle fibres – slow twitch (type 1) and fast twitch (type 2). The fast twitch fibres can be further divided into type 2a and type 2b. Of these type 1 muscle fibres have the greatest level of fatigue resistance. And, of the fast twitch fibres; type 2a muscle fibres are more fatigue resistant than type 2b. Type 2a fibres also known to have a much greater level of adaptation to muscular endurance training than type 2b. In fact, type 2a muscles can become very similar to slow twitch muscle fibres after many years of training.
The percentage of each muscle fibres varies between different athletes. Athletes with a greater percentage of the more fatigue resistant muscle fibres tend to have a greater level of muscle endurance. In addition, they respond more effectively to endurance training.
Muscular endurance Training
Training can have a significant effect on muscular endurance. Muscular endurance training is any training that can lead to improvements in muscular endurance. In this sense traditional endurance training, high intensity interval training and strength training can all be effective for developing muscular endurance. In particular, both high intensity interval training and strength training can lead to improved fatigue resistance of type 2a muscle fibres. The addition of strength training to an endurance athletes training can be particularly effective for development of muscular endurance.
The effect of muscle strength can often be overlooked when related to endurance. However, muscle strength can have a clear effect on muscular endurance. The reason for this is simple: when we have a greater level of maximum strength, it becomes easier to work at submaximal intensities. So, if you increase your maximum strength then you will be able to perform more repetitions at lower intensities.
Genetics and Muscular endurance
Genetics clearly plays a role in muscular endurance on a number of levels. Firstly, our genes affect the percentages of different muscle fibre types. Secondly, and of equal importance, our genes affect how we adapt to different types of training. In particular, our genes can determine how well we adapt to either strength training or endurance training. However, it’s important to remember that our genes never work in isolation and it’s a combination of both our genes and environment (training, nutrition, support, coaching etc) that determines long term success.
Muscular endurance exercises for sport
The most important factor when looking to improve muscular endurance for a sport, is to train in ways that are specific to your sport. Think about what muscles require muscular endurance when you compete. Should you be working a specific muscle in isolation? Or, targeting a group of muscles? As an example, a runner or cyclist might include the following muscular endurance exercises: calf raises, lunges, squat, deadlifts, resisted knee drives.
How many reps should you use when developing muscular endurance? A lot of athletes look to develop muscular endurance by using higher rep ranges. A typical example might be sets of 20-25reps, or even higher. Using reps in this range will lead to the development of muscular endurance.
Using slightly heavier weights with a lower rep range is also effective. Completing sets of 10-15reps can also be effective for the development of muscular endurance. This not only improves muscular endurance but also improves muscle strength. This makes exercising at sub maximal intensities feel easier and less fatiguing. Another benefit is improved exercise efficiency. Meaning that you require less oxygen when exercising at a given exercise intensity.
Muscular endurance can be further improved by making the muscular endurance training highly sport specific. A good example would be a runner, completing hill running training. Another example could be a rower completing intervals at a higher resistance level or swimmer using hand paddles.