8.4 Endurance training volume
The possibility also exists that the total volume of endurance exercise,rather than the intensity per se,may be more crucial in mediating concurrent interference.A role for volume-dependent interference is supported by studies reporting no interference with smaller endurance training frequencies(=2 sessions per week) whilst others have observed attenuated maximal strength with larger endurance training volumes(=3 sessions per week).Greater attenuation of strength and hypertrophy(estimated via limb girth) has been shown to occur with greater frequencies of concurrent endurance exercise (3 days per week for each mode) than when endurance exercise was performed once per week.Nevertheless,it remains to be determined whether the total weekly endurance training volume,or the training frequency per se, is the more critical factor mediating concurrent interference.If endurance exercise volume is key, low-volume HIT protocols might confer benefit when incorporated into a concurrent training regimen by limiting any potential volume-dependent interference effect,whilst also offering similar metabolic and performance benefits to traditional endurance exercise.Further work in this area is required to inform the manipulation of concurrent endurance training volumes and/or intensities in order to minimize their potentially negative impact on resistance training adaptations.