1.2.b. Preparation and training methods (strength training) GapFill

There are many sporting activities that require the use of different types of strength:

•  GripMaximumMinimalVertical strength - The maximal force that can be produced in a singular contraction. This is used in activities where a single action is performed to shift a heavy object, such as a weightlifter performing a max effort deadlift (isolated action of hip extension). The contraction tends to be slow to overcome the inertia of a static object, so it could take 5-10 seconds to perform a rep.
• Explosive/  StaticStretchFlexibleElastic strength - The ability to produce a great amount of force as rapidly as possible. It is rare for these movements to last longer than 5 seconds. They are often preceded by a movement that gathers momentum (i.e. an eccentric contraction), followed by a movement which generates power (i.e. a concentric contraction). These are known as  repetitionplyometricstaticrecovery movements and are depicted by physical activities such as a push-up clap and a squat jump, as well as sporting activities such as a powerlifter performing a clean and jerk.
•  StaticEccentricElasticDynamic strength - The force generated during movement and when the muscle changes length. Similar to explosive strength, this movement generates power by combining strength and  reactionspowerflexibilityspeed over a short period of time. This is a common type of strength used in sport, such as the hockey player who attempts a legal shoulder barge when competing for the ball, or the cricketer overcoming the resistance of a ball by playing a defensive shot which sends the ball in the opposite direction. These movements usually don't require much recovery time before they can be performed to the same intensity again.
•  ElectricSteadyDynamicStatic strength - The amount of force a muscle can exert when its length remains unchanged. These movements are characterised by  angularisometricRecoveryisotonic contractions and could occur over a longer time period. For example, rugby forwards engaging in a scrum could maintain this type of strength exertion for up to 10 seconds. 
• Strength  capacitymaintenanceaerobicsendurance - The ability of the muscle to produce forceful contractions over a sustained period of time. This type of strength widely differs from the others, in that it occurs over a longer  repetitiondurationweightintensity and is physically demanding, requiring an equally long recovery time. It is apparent in sporting activities such as rowing where performers are required to produce many repetitions of pulling the oars to overcome the resistance of the water.

There are two major factors that affect the strength of a muscle, affecting the force that it can produce: 

• The characteristics of Type IIa muscle fibres are only really suited for   isometricstrength endurancedynamic strengthstrength extension because of their greater resistance to fatigue.
• Type IIb fibres will be recruited for most strength-based activities, due to them being the most effective in generating large forces over a short period of time. Therefore, they are more suited to maximal or  ballisticstaticexplosiveisotonic strength activities.

• The amount of force that can be produced by a muscle is positively correlated with this factor. This is because there is a greater size and number of actin and myosin filaments, as well as a greater efficiency of  oxidative enzymesaxonsmotor unitsglycolyric enzymes to innervate a more synchronised contraction of muscle fibres.

Other factors affecting strength are:

• Age - Peaks are seen at around 25-35 years of age
• Gender - Males have higher levels of circulating  enzymesoestrogentestosteronehaemoglobin than females, which generally translates into a greater muscle strength
•  CardiovascularPassiveMetabolicErgogenic aids - Legal supplements such as creatine increase the amount of stored PC in the muscle, whereas synthetic copies of the human growth hormone and anabolic steroids are illegal means of increasing muscle strength