CoachGKX

I’ve used the Yo-Yo IRT1 from this app and it works well with one issue: the VO2 max calculations are way off. Best to do your own calculations as follows: VO2max in mL/min/kg=(meters covered x 0.0084) + 36.4. If you do this you will get a realistic predicted VO2 max. The formula for the YYIRT2 =(meters covered x 0.0136) + 45.3. Formula from topendsports. The YYIRT1 on this app ends at 16:0 and many elite athletes may exceed this.