For example , sixtime IRONMAN World Champion Mark Allen famously adhered to the Maffetone 180 - minus - your - age method for training and racing .
There are huge benefits to training with a GPS and heart rate monitor in some instances .
Sixtime IRONMAN World Champion Mark Allen famously adhered to the Maffetone 180 - minus - your - age method for training and racing .
There are huge benefits to training with a GPS and heart rate monitor in some instances .