Today while swimming my fast, easy workout I considered interval training.

Interval training as it is normally understood is meant to be hard training designed to create lactic acid and fatigue.

Yet, fatigue generally does not help technique. As we fatigue our technique tends to fall apart and we start to struggle.

While I think it is worthwhile to practice intervals teaching ourselves to delay the fatigue and delaying the loss of technique, I think it is detrimental to do intervals beyond the point of our technique dropping off.

I think this is particularly true for triathletes whose anaerobic systems are already highly developed from running and cycling. Anaerobic capacity is more about body chemistry. Aerobic capacity is more about specific muscular endurance. I think developing superior aerobic capacity in our swimming muscles is wise. The arteriole development from aerobic training is unlimited and will pay off. In fact, superior aerobic capacity allows athletes to delay the need to switch to an anaerobic production of energy.

The well trained swimmer, runner or cyclist who is breathing easily is working aerobically and if we are huffing and buffing and barely keeping up with them then we are probably working anaerobically. The person whose goes anaerobic first in a distance event, generally loses.

So, if I am losing technique while doing my fast, easy intervals, I stop doing them. I think it does me more harm to lose good swimming technique compared to the little benefit that I would gain in body chemistry. As a long time runner and cyclist, I think that my anaerobic capacity has been developed well enough away from the pool. I think the water and my swimming time can best be used improving my technique while growing the arterioles in my swimming muscles.