The term "strength " is generalized much too often among athletes. People generally believe strength is very discrete, that is, either you are weak or
strong; you are fast or slow. However, an athlete needs to develop many different kinds of strength. Depending on the athlete s specific sport, some
of these strengths need to be developed more than others. Strength can be defined as the ability to overcome resistance: to lift or move a weight
through a particular range of motion. A formula used in physics to define strength follows:
strength = force x distance
From this equation one can see two variables define strength. The force variable is the actual force outputted by the individual performing the
exercise. In this case force is equal to the weight being lifted. The second variable is distance, or the range of motion. Distance is the distance
the weight is moved by the individual.
Athletes in different sports need to exhibit specific strengths in a manner that will help them best achieve their primary goals in whatever sport
they are involved. Strength athletes such as bodybuilders, weightlifters, powerlifters and athletes involved in speed sports all focus on different
strengths to perform at their optimal level. Developing only one type of strength will not bring about favorable results for all the movements
required by each specific sport. To better understand the concept of training multiple types of strength, let's examine the different types of strength.
Maximum strength is the maximum amount of weight an individual can lift for one repetition with respect to a particular exercise. Powerlifting comes
closest to displaying pure maximal strength. In powerlifting the athlete lifts the maximum weight possible through a specific range of motion when
performing the squat, bench press or deadlift. Maximal strength places emphasis on the weight being lifted rather than on the distance the weight
travels or number of reps performed. Thus the amount of weight is the major factor in the strength equation. The heavier the weight lifted the more
force needed to complete the lift. According to the strength equation, the magnitude of strength increases as well with an increase in force.
Strength endurance focuses on the volume of work done for a particular exercise and not on the weight being lifted. The concept of strength endurance
emphasizes the number of repetitions that can be executed with a sub-maximal weight. Strength endurance focuses on the distance variable in the
strength equation. A lifter who squats for 20 repetitions has covered more distance than a lifter of the same size who squats a one-rep maximum. The
lifter performing 20 repetitions has covered a distance 20 times greater than the lifter that performs a one-rep max. However, the lifter performing
a maximum-effort lift has utilized more force. Both lifters are exhibiting strength according to the equation, but two distinct types of strength
Explosive strength is the ability to generate a very quick and explosive contraction of the muscle. This type of strength can be generated by using
little or maximal resistance or somewhere in between. Jumping with one s bodyweight or throwing a baseball are examples of little resistance. Throwing
a medicine ball is a good example of moderate resistance. Olympic weightlifting where the lifter must quickly press the weight overhead is a prime
example of explosive strength with heavy resistance. The key point to keep in mind is to achieve maximum force as quickly as possible after an intense
A time variable can be added to the strength equation to determine speed strength. Speed strength is commonly referred to as power. The power equation
can be written as follows:
power = (force x distance) / time or power = strength x speed
As you can see from the power equation, strength and power are not the same. Strength is how hard you push or pull. Power on the other hand is how
hard you push or pull in a specific time period. Power is basically a product of strength and speed. Let's look at two similar movements - a squat
and a vertical jump. A lifter doing the squat can increase the weight resistance used, allowing him to exhibit more strength. This strength increase
allows him to add to the first part of the power equation. The squat movement becomes slower as the weights get heavier, thus taking away from the
second part of the equation, speed. Squatting re-quires higher amounts of strength, but moderate amounts of power are generated because of the slower
speed when the resistance is heavier. On the other hand, a basketball player performing a vertical jump has to lift his bodyweight. This amount of
weight to be lifted is moderate in terms of strength, but the jumping movement is fast, taking less than a second. This quickness increases the speed
part of the power equation, thereby increasing the power output. To jump high, the basketball player requires a lower level of strength but a higher
level of power because of the speed component involved.
Isometric strength is the amount of strength an individual possesses at a single point in the range of motion of an exercise. When one is displaying
isometric strength, no motion is visible, and no limbs or joints undergo any movement. However, some shortening of tendons and muscle fibers occurs
internally. A good example of an isometric contraction is holding a weight in the same position for a particular amount of time. Isometric strength is
utilized in almost every exercise. Let s take a look at this type of strength as it's used in the bench press.
After lowering the barbell to your chest (i.e. the eccentric motion), you must stop the movement of the barbell before reversing and pressing the
barbell (i.e. the concentric motion) to complete the lift. The period where you have stopped the weight on your chest, before changing directions, is
where you are exhibiting an isometric contraction. Many bodybuilders add isometric contractions to their exercises to develop greater tension for more
strength and muscle mass gains. An exercise for which most bodybuilders use isometric contractions is the biceps curl. Just throw in some isometric
contractions between reps of your biceps curls and you will really feel the burn.
The Strength Relationship
Even though many types of strength exist and each type is quite distinct, they are all interrelated. For example, maximal strength is the basic strength
that influences speed strength, strength endurance, explosive strength and isometric strength. However, one cannot simply increase maximal strength and
expect all other forms of strength to in-crease. Each is a separate entity and must be trained differently. One must focus on his specific sport of
interest and recognize what strengths are needed to achieve specific goals. After recognizing what strengths need to be developed, the athlete should
tailor his training program to develop those specific strengths.