Why does running ruin flexibility so much more than does cycling?

If you do a lot of distance running you may be aware that there is a progressive loss of flexibility of the running muscles. This is a progressive process that slowly reduces the long flowing stride of adolescent years to a painful looking middle-aged hobble that looks more akin to a tip-toe through the tulips than an awesome display of sustained athletic prowess. No matter how diligent one is with stretching, the battle to maintain flexibility seems to be a lost cause.

Although cycling is a highly repetitive and restrictive action, there is little consequent loss of flexibility (Mind you, some of the worst sporting posture one will ever see are found in cycling; but this is mostly due to muscle imbalances and sloppy habits).

The differences are due to the differing effects of concentric versus concentric exercise on the body.

All exercise is a combination of concentric and eccentric exercise. What varies is the content.

Concentric = shortening muscle by its own contraction

• Muscle relaxes while lengthening
• No tearing of muscle tissue – no muscle soreness
• Blood flow through the muscle is enhanced
• Risk of muscle and tendon injury is very low
• Recovery is 24-36 hours

Eccentric = contracted muscle is forcefully lengthened

• Blood flow is occluded
• Contracting muscle is forcefully lengthened
• Causes delayed onset muscle soreness
• Risk of muscle and tendon injury is high
• Recovery is 3-5 days

When the tissue that was damaged from eccentric exercise is repairing, fresh collagen is being laid down. The tendency is for this to cause the muscle to lose elasticity and length.
Cycling is close to 100% concentric exercise, as are sports like rowing and swimming. Running, on the other hand, is probably 50% eccentric and this rises to almost 100% when running downhill. Walking is much less eccentric in nature than running, so it is much safer to do.
Eccentric versus concentric explains why a cyclist can ride hard day after day without apparent ill effects and why swimmers can train for hours every day of the week. Because running is highly eccentric in nature the damage to tendons and muscles is high necessitating great care with ensuring adequate recovery between training sessions. This is why a good running programme seldom has you running hard or long on consecutive days.
How do we prevent this progressive loss of flexibility and painful knots (trigger points) in muscles and tendons?



How to maintain flexibility when running a lot

• Do not run hard on consecutive days - do other activities in between that take the muscles and joints through their full range of movement. This can be Yoga, dancing, gym work or simple calisthenics, for example
• Do not run hard out downhills, especially on hard pavements - this is just too damaging to the muscles and tendons
• Do running drills at least once a week in running training that take the muscles and joints through their full range of motion (Running goach, Arthur Lydiard, made good use of hill bounding and other drills to produce athletes with awesome strength and power)
• Stretch daily, preferably after a long hot bath and do so Yoga-style. Refer to these exercises. And these ones.
• Ensure your body has plenty of antioxidants, including vitamin C inside to soak up damaging free radicals that are produced by damaging eccentric exercise. Additional omega oil in the form of flax seed and fish oil may assist with prevention and repair, as will joint food formulas which are beneficial for all connective tissue of the body
• Take supplementary magnesium and B vitamins to assist with relaxing the muscles and nerves.
• Have a deep tissue massage of the running muscles up to three times per week, concentrating on softening any hard and painful knots