Strengths of the study Many studies attempted to examine the effects of psychological factors on athletic performance using subjective performance as the criterion (e.g., Beedie, Terry & Lane, 2000; Lane & Chappell, 2001; Prapavessis, 2000). This provides vague information about the association between psychological factors and real performance. To fill this gap, we used seven indices of the Volleyball Information System developed by FIVA and examined its associations with mental energy.
