Spinervals 27.0 - Threshold Test & Suffer Fest serves Videos

Product Description

Spinervals 27.0 - Threshold Test & Suffer Fest serves dual purposes. A great threshold building workout designed to boost your anaerobic threshold and sustainable power output for time trialing events including triathlons, this workout also functions as a repeatable 'field test' used by many prominent coaches and exercise physiologists to determine an athletes 'Functional Threshold', or that output of work (power) one can sustain on average over a 20 minute period.