Running - Understand your muscles and reach your PB!

Your body is a work of art and should never be taken for granted. The simple task of reading this blog requires intricate movement and control of various muscles in your body. Your core is constantly firing to keep you in equilibrium to prevent you from falling over. At the same time your hands and fingers are meticulously clicking and scrolling on your mouse or scroll-pad. Finally, there are 6 eye muscles in each carefully scrolling through this fascinating article - now read on!

Taking a look at your skeletal muscle anatomy and the types of fibers found within your muscle allows you to train in a specific way to achieve a particular goal (Marathon runner or Arnold Classic competitor).

There are 2 types of fibers mentioned in the literature, these are:

1. Fast twitch fibers (AKA Type IIa and Type IIb): Develop forces quickly and relax almost instantly - Greater percentage in bodybuilders and gym goers.

2. Slow twitch fibers (Type I): Develop forces slowly and relax slowly - Greater percentage in distance runners.

The comparison between the 2 fiber types stems from their demand for energy and consequent fatiguability. Type I muscles are efficient and take long to fatigue and therefor are the main workers in long distance running, cycling and general endurance sports or aerobic activities. Type II fibers are responsible for short bouts of activity requiring high speeds, forces and power. These fibers will fatigue quickly due to their inefficient energy utilization properties.

So what does all this la-di-da mean for you?

Long Runs - HELLO MILEAGE!!!

Those sometimes dreaded Sunday LSD’s on your workout schedule are there for a reason. These target your slow twitch fibers by making them more energy efficient. Proper training will lead to increased lengths of time to hit fatigue. Interestingly, more frequent LSD’s will in turn produce a greater total percentage of what I like to term “Marathon muscles”.


Also termed anaerobic threshold runs, is key to your quest for a PB. It is performed at around “25 - 30 seconds per mile slower than your current 5km race pace”. This is according to Jack Daniels (PhD) who glamorized the Tempo Run in his book, “Daniels Running Formula” In science, improved lactate clearance ability translates into improved running performance – This is what is achieved in Tempo runs.

The benefits of tempo runs are achieved through slow-twitch and intermediate muscle fiber recruitment (Type IIa). Slow twitch fibers are cued maximally during tempo runs, however the recruitment of Intermediate fibers is an addition to the PB recipe during tempo runs.

Finally, your emotions are challenged too during tempo runs. This is the difference between shaving those final minutes or seconds off your PB.

Short Repeats

Often really challenging, high intensity interval training (HIIT) is an integral part of any running program. We use them to recruit fast twitch and intermediate fibers (Type IIa and IIb). The most commonly used distance is 400m which is repeated 6, 8, or more times depending on your workout. The more you can include short repeats in your program, the more efficient your running will become. This is because it optimizes our neuromuscular coordination, allowing the brain to cue muscle firing accurately and more efficiently.

The Dreaded Hill Repeats – AN UPHILL BATTLE!!

For so many coaches, hill repeats are considered the holy grail of training for your 10K,21K and Marathons. It is a change from your usual routine thus keeping things fresh and it is the one workout that engages the entire body both physically and mentally. It is also the one workout that utilizes all three muscle fiber types to create a powerful moving machine that is you. It is no doubt that hill repeats will make you a faster runner overall as it builds a solid muscle foundation. The added benefits are great looking calves and a tighter, more athletic physique – Now that will get the much appreciated and cliched crowd cheering "LOOKING GOOD!" come through!


Having this information stored at the back of your mind will allow you to tweak your program in a way that optimizes your strengths and weaknesses. No program is universally appropriate. We all download running guides/programs and try stick to them, but they key is keep them as a guide only. This means customizing it over the weeks to benefit your fitness levels and goals. Not only will you see the results, but your training will be more enjoyable.

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