Invited Session "Rate of force development: methodological, physiological and practical issues"
Contractile Rate of force development: Practical implications
Aagaard, P.
University of Southern Denmark
Rapid force capacity (“explosive muscle strength”) is measured as the maximal contractile rate of force development (RFD), and
reflects the ability of the neuromuscular system to generate fast and steep increases in muscle force at the onset of contraction.
Resistance training is known to elicit significant gains in RFD due to increases in neuromuscular activity (EMG amplitude, rate of
EMG rise) in the initial phase (0-200 ms) of muscle contraction, with an additional contribution from training induced gains in muscle
size and tendon stiffness, respectively. The rise in RFD evoked by training allows for an enhanced acceleration of movement,
elevated limb speed during short-lasting movements, and increased muscle force and power to be produced during fast movements.
Consequently, gains in contractile RFD are important not only to athletes but also for elderly individuals to improve horizontal walking
speed and ensure optimal postural balance.
Power athletes demonstrate greater RFD along with elevated neuromuscular activity during the onset of muscle contraction
compared to age matched controls. Muscle overuse injury leads to greater acute impairments in RFD than MVC, indicating the
presence of selective neuromuscular impairments. Increases in RFD and maximal muscle power have been observed following
resistance training in various patient groups (hip replacement, myalgia, COPD, fall patients), including elderly sarcopenic individuals.
Elevated RFD may also be observed both in young and elderly individuals with other types of high-intensity exercise, e.g. recreational
soccer training.
Thus, a high degree of adaptive plasticity appears to exist for RFD, which plays an important functional role for athletes, patients
and frail elderly adults alike.
11 фев 2016
