Endurance Requires "Strength Endurance"

Strength is the ability to exert force. But what kind of force (game) do you want to do? It has a lot to do with way you set your bike up.

The main characteristic of muscular tissue is that it is contractile and therefore responsible for movement! It is the contractile proteins that contract and if they are not over lapping, they can't do provide their ratchet effect! In other words a saddle that is too high or too low will not allow you to get the most of your muscles.

The amount of energy expended during an eccentric contraction is always less than that observed during a concentric contraction for the same muscle. The amount of metabolic work associated w/ eccentric contractions is 1/3rd to 1/13th of the work of concentric contractions.

For example, the erector spinae of the low back work harder and show higher levels of recruitment when up and on vs. when going down into a forward flexion. So you go get fit and they move your stem up and you wonder why your back hurts?

Maximizing force development requires coordination. Genetics has a strong influence for your capacity within a genetically-determined "performance envelope." As with any training, training for rhythmical events involves the basic principles of overload, specificity, reversibility, and individuality. The greater the stimulus, the greater the adaptation and note they are not permanent and regression back to a untrained state.

You hear a lot of people saying your need to look at your flexibility before performing a fit.
The factors affecting flexibility is limited by anatomical obstructions, neurological reflex, and muscular constraints.

Anatomical obstructions - bone, fat, skin, joint capsules and ligaments, muscle mass. These structures simply get in the way of joint motion.

Neurological reflex - simply activate or inhibit the muscles i.e. golgi tendon organ or intrafusal muscle fiber. Muscles spindles have a set-point.

Muscle constraints - muscle length & muscle stiffness affects its range of motion

Anatomical constraints - little can be done i.e. large muscles, obesity, or pregnancy. So loss of weight greatly improves your flexibility.

On the bike - when muscles are positioned or immobilized in one shortened position like a saddle that holds you in one spot, you tend to lose sarcomeres, and, at the same time, muscle stiffness increases. Just the intrinsic viscosity can make them stiff i.e. edema, cell damage.

Muscle stiffness & elasticity can be altered "only slightly" and w/ long term training. No question, elastic energy can be useful if it can be coordinated into the motor movements i.e. quads and lower back, upper body i.e. tt, tri, etc... Sarcomeres are added to and removed from muscles in response to chronic stretch. When muscles are immobilized in a position, they tend to lose sarcomeres, and at the same time, muscle stiffness increases i.e. lower back muscles, neck.

Improvements in skill can occur through out life and can thus contribute to maximum force development.

Athletes that accelerate & exert force rapidly i.e. lineman, sprinters do this within a few seconds. They develop large muscles (hypertrophy) as they focus and work to acquire the kind of strength needed for the activity.

Cycling also require strength, however it is not like explosive sports. Cycling strength is more about the ability to exert less than maximum force for a long time. Cycling strength is typically developed through over-distance & interval training.

Sports like alpine skiing, require the participants to exert static strength for prolonged periods. The tuck requires the athlete to remain in a more static position (force without movement). To learn to tuck you have to spend time doing it!

An interesting aspect of skeletal muscle is its adaptability. If a muscle is stressed (within tolerable limits), it adapts and improves its function. Likewise, if a muscle receives less stress than it's used to, it atrophies.

The purpose of physical training is to stress the body so it improves its capacity to exercise. It is beneficial only as long as it forces the body to adapt to the stress or effort. If the stress isn't sufficient to overload, no adaptation occurs.

When an athlete is working hard, fitness is high! If your bike fit doesn't allow you to go hard, your fitness is low! As long as a threshold tension is developed, increases in strength will occur.
Cycling up steep hills, for example, develops a certain amount of muscle strength. The same is true for sprints, if you don't do them, you should not expect to do them. You don't develop the needed contractile protein. This is different than the rider who develops mainly sarcoplasmic protein (oxidative enzymes, mitochondrial mass, etc.).

So, muscles adapt specifically according to the nature of the exercise stress. This is why we don't have one fit for all events. The road fit is not the mtb or the tt vs. the tri, they have different needs.

This means that the muscle exercised is the muscle that adapts to the training. If you train the leg muscles, they-and not the shoulder muscles, for example- are the ones that hypertrophy.

So if you want to do tt, you better do your time and train that "static strength (force w/o movement) for the legs to work under and against!