Types of Strength

Most athletes (and coaches for that matter) don’t realize that there are different types of strength. And depending on the demands of your sport, it will make an enormous difference on what type of strength it is that you should train for. So, let’s get some definitions out of the way:

Absolute Strength: The maximum force an athlete can generate, regardless of bodyweight and time of force development. For example, absolute strength is important to lineman in the sport of football. Athletes of other sports typically need not worry much about absolute strength output. Why? Because an athlete’s absolute strength is simply a non-factor because of the brief amount of time and distance that most sport activities allow/require.

Limit Strength: The maximum amount of force your muscles can produce under any condition. This type of strength is not likely to be seen except under the most extreme of circumstances, such as life-threatening situations when adrenaline is running.

Maximal Strength: The most force your muscles can produce voluntarily during training and/or performance. Maximal strength includes concentric, isometric, and eccentric muscular contractions. The human body can voluntarily produce the greatest force during an eccentric (negative) contraction.

Optimal Strength: The ideal level of strength needed so that any further development would not improve performance. For example, a distance runner only needs to have a certain amount of upper body strength to maintain proper running form.

Relative Strength: The maximum force an athlete can generate per unit of bodyweight, regardless of time of force development. This type of strength is important to jumpers and gymnasts.

Strength Endurance: The ability to maintain force in extensive/intensive workloads or repeated sub-maximal efforts. This type of strength is important for sports such as swimming, distance running, and cross-country skiing.

Speed Strength: The ability of the neuromuscular system to produce the greatest possible force in the shortest possible time frame. Or, practically, it can be defined as the ability to apply force rapidly and/or at high velocities. Speed strength can be further broken down into 3 types of strength:

1) Starting Strength: The ability to produce a high level of force at the beginning of a muscular contraction (the initiation of force).
2) Explosive Strength: The ability of the neuromuscular system to continue developing the already initiated force as quickly as possible.
3) Reactive Strength/Ability: The ability to switch rapidly from an eccentric to a concentric contraction.

Strength Speed (not to be confused with speed strength): a learned process to push near maximal loads as fast as possible. This can usually only be done with the use of accommodating resistance such as bands or chains. It is sometimes associated with Accelerating Strength.

Summary

No matter what sport we train for, we should remind ourselves that most athletic tasks involve brief execution times and/or force being applied over very small distances. Therefore, they DO require high rate of force development. The graph below is the force-time curve. This curve shows force as a function of time (i.e. power), maximal rate of force development, and the amount of force for subjects of different training methods. Impulse is the change in momentum resulting from a force, and is represented as the area under each curve. Obviously, the more force that we are able to apply, in the least amount of time, the more power output increases. This results in greater overall performance on the field, track, or court. In contrast, we can see from the chart that peak force production, better defined as maximum/absolute strength requires up to 0.8 sec in dynamic movements and 3+ seconds in isometric movements. This is much longer than most sport demands allow. For example, force is only applied for 0.08 - 0.2 sec (80 – 200 ms) during the ground support phase of running.