From a lot of the reading I’ve been doing, if I’m going to run a full marathon anytime soon I’m going to need a heart-rate monitor (so no more sneering from me at technophile-runners if I go that route). Stamina running is defined by Greg McMillan* as when you’re running “between 30K and 8K race pace… [and] your heart rate is between 83 and 92% of its maximum.” Well yeah, guess I’ll need a monitor sometime if I’m to work out when I’m in that kind of zone.
The skinny on this kind of training is what it does to your body’s ability to deal with lactate and hydrogen ions, which join together to make lactic acid (before splitting apart again for some reason that’s not too clear to me). Light exercise produces lactate in low levels. Your body deals with low levels by moving it around the body where it can be recycled as fuel (called “shuttling”).
There’s a maximum level at which the body can deal with lactate before it starts to accumulate in the muscles and cause fatigue and tiredness. That’s your lactate threshold. Stamina training works to make the body more efficient at processing and shuttling the lactate and thereby raises the lactate threshold.
A similar process is at play with that hydrogen ion, which again can only be precessed by the body to a certain point. Once reached, acid accumulates in the body and you find yourself feeling damn tired.
According to McMillan, “that the speed at your lactate threshold is the most important factor in distance running success (5K to marathon racing). Push your lactate threshold faster and you will race faster over all distances.”
Seems fairly important then!
*The information on the benefits of different types of running in this and a few other posts is cribbed from Greg McMillan’s Six-Step Training System, Step #2: The 4 Key Training Zones – Endurance, Stamina, Speed & Sprint. For others, see posts tagged Greg McMillan.