Physiological Rationale

When carrying out resistance training, an athlete will experience many physiological adaptations as a result of overloading the skeletal muscular system. Referring back to the force-velocity relationship for power club level athletes need to be initially focusing on increasing force (strength), then after a solid foundation move onto increasing the velocity (Cormie et al, 2011). Ronnestad and Hansen (2011) found that a 12 week strength training period in well trained cyclists increased squat jump power test results by an average of 13% pre to post.

Figure 3. Pre -post squat jump test results in independent groups. (Ronnestad and Hansen)

Cormie et al (2011) discussed how the force produced by muscles decreases as velocity is increased, so specified strength training should be carried out under a low velocity however the contractions should still be isotonic to help the progression to power training.

Why is the Force vs Velocity relationship so important?

Due to the force of a muscle being determined by the number of cross bridges attaching, increases in velocity results in less cross bridges being able to connect, therefore less force due to the length of the sarcomere, this is also known as the length – tension relationship   (Leiber et al, 1994).

A further factor in the force velocity relationship is the cross sectional area of the muscle (CSA) and fibre type. The larger the CSA of the muscle, the more single fibre strands available to contract and provide more force (Cormie, 2011), however the type of muscle fibre has a vast effect on the strength of the athlete. Type IIa muscle fibres (fast twitch) have the greastest hypertrophy ability followed by IIb (Bird et al, 2005; Stone et al, 2006). Previous studies have shown up to 45% of muscle fibre type is pre-determined by genetics (Simoneau and Boucard, 1995), however Hedrick et al (2008) looked at how type IIb fibres could be enhanced through resistance training to gain type IIa traits, therefore increasing an athlete’s CSA of type IIa fibres, increasing strength and power.

Muscular architecture is another area determining the strength of an athlete, Clark et al (2006) found that the thickness of the medial head of a muscle predicted the isometric and isotonic force produced, the thicker the muscle, the greater force produced. The pennation angle is the angle between the line of action and the muscle fascicles (Cormie 2011). In low velocity resistaance training when pennation angle increases, muscles are able to work nearer their optimum length with reference to the length-tension relationship, therefore generating more force (Cormie, 2011). 


Biomechanically increased strength will allow the production of greater force, resulting in decreased contact time, leading to a possible increase in stride frequency which will improve acceleration (Spinks et al, 2007). Hockey players with faster acceleration stand more chance of losing their marker, or reaching the ball first to gain possession for their team.

Image 1, Strength in Field Hockey.