In human locomotion the ability to generate and sustain power output is of fundamental
importance. This review examines the implications for power output of having variability
in the metabolic and contractile properties within the population of muscle fibres
which comprise the major locomotory muscles. Reference is made to studies using an
isokinetic cycle ergometer by which the global power/velocity relationship for the
leg extensor muscles can be determined. The data from these studies are examined in
the light of the force velocity characteristics of human type I and type II muscle
fibres. The ‘plasticity’ of fibre properties is discussed with reference to the ‘acute’
changes elicited by exercise induced fatigue and changes in muscle temperature and
‘chronic’ changes occurring following intensive training and ageing.
Pedalling rate - cycling - fibre type recruitment - mechanical efficiency
