The Efficacy of Flywheel Inertia Training to Enhance Hamstring Strength

Abstract: The purpose of this narrative review is to examine the efficacy of flywheel inertia training
to increase hamstring strength. Hamstring strain injury is common in many sports, and baseline
strength deficits have been associated with a higher risk of hamstring strain injury. As a result,
strength and conditioning professionals actively seek additional techniques to improve hamstring
strength with the aim of minimising the incidence of hamstring strain injury. One method of strength
training gaining popularity in hamstring strength development is flywheel inertia training. In this
review, we provide a brief overview of flywheel inertia training and its supposed adaptions. Next,
we discuss important determinants of flywheel inertia training such as familiarisation, volume
prescription, inertia load, technique and specific exercise used. Thereafter, we investigate its effects
on hamstring strength, fascicle length and hamstring strain injury reduction. This article proposes
that hamstring specific flywheel inertia training can be utilised for strength development, but due
to the low number of studies and contrary evidence, more research is needed before a definite
conclusion can be made. In addition, as with any training modality, careful consideration should be
given to flywheel inertia training determinants. This review provides general recommendations of
flywheel inertia training determinants that have value when integrating flywheel inertia training into
a hamstring strengthening program.