Observations of the German junior elite cycling teams training behaviours (href=”http://www.ncbi.nlm.nih.gov/pubmed/20861522) prompted some discussion among athletes and coaches. After a 15 week base building period, it seemed those who improved the most logged significantly more low intensity ‘aerobic’ training hours and less high intensity ‘threshold’ hours. While there there are many confounding factors it does raise the question is high intensity simply no substitute or can it actually be detrimental to aerobic development?
It is not my view that higher intensity training is detrimental rather the unstructured, undisciplined way it is conducted here that is the problem.
“Why the benefit of lower intensity vs higher is a good question” asks leading triathlon coach John Dargie “and I’m not sure I have the answer. The lower intensity is to my mind much more reproducible – if done properly and fueled appropriately it can be done every day. Threshold stuff is fatiguing, levels more variable day by day. Also threshold is often badly done, with average intensity correct but control of intensity within sessions too variable. You don’t need to go much over threshold (3-5% or less) for it to be very fatiguing and hence unsustainable”
It is well accepted that focused low intensity aerobic training or ‘base training’ is important to stimulate adaptions required to perform to your potential. These adaptions include:
Metabolic- adaptions allowing better fuel utilisation, oxygen transport and lactate clearance. For instance increases in beta fatty acid oxidation, increased muscle myoglobin and an increased propoetion of LDH-H.
Cardiovascular- adaptions resulting in increased cardiac output, muscle oxygenation and oxygen transport. For instance increased stroke volume and heart rate, increased capillarisation of muscles and increase plasma volume and red cell number.
Pulmonary- adaptions allowing improved blood gas exchange for example strengthening of respiratory muscles and increase tidal volume.
It my experience the way to train any physiological system is to frequently repeat a stress that targets the system. When it comes to the aerobic system that target is the aerobic threshold (AeT) which is basically which is hard to pin down but is basically where your breathing become such that you can no longer comfortably breath through your nose. It will be around the last baseline point on a lactate curve or below VT1.
When training at the aerobic threshold all of the key aerobic systems are stressed and the stress can be sustained for extended periods at a time without disproportionate levels of fatigue.
“The problem with base workouts” says Joe Friel author of Triathletes Training Bible,“is that it seems too easy at first so the athlete is tempted to abandon their aerobic zone and start riding variably paced with hard and easy efforts – fartlek intervals, essentially. And by so doing reduces the aerobic benefits of the day’s workout.”
It is possible that the high intensity work could be detrimental for instance by increasing the production of catabolic hormones such as cortisol and glucagon. It is likely however that it was the riders that showed the most discipline to remain in their optimum training range rather than giving in to the temptation to let pace vary that reaped the rewards.
In short, take care to control your efforts, reserve hard efforts for specific workouts, make your basic aerobic training count and if your coach tells you to go easy then they probably mean EASY!