I opened up my copy of the UKSCA journal this weekend and read with great interest an article by Dr James Morton reviewing the literature surrounding some new training methodology for endurance athletes. It surrounds gaining specific endurance performance adaptation by altering your pre-training nutritional status.
One of the major physiological adaptations we try to get from endurance training is an increase in cell mitochondrial mass that, without going into great detail, allows you to perform at higher intensities for longer. The research area reviewed is finding some data to suggest that the best way to increase your mitochondrial mass is to train with reduced carbohydrate stores. One recommendation is to utilise a training block where instead of training daily, you train twice every second day and allow the second session to be the one with reduced carbohydrate stores; perhaps using a high intensity interval session to target that adaptation.
Before you start applying this to your own sessions there are a couple of considerations. There is no evidence to suggest that this works with resistance training. A prolonged period of exercising with low carbohydrate stores may lead to reduced immune function and increased risk of illness and as such may require an increased intake of certain vitamins and minerals, namely vitamin C, vitamin A and zinc, to reduce this risk. Finally, it is difficult to directly measure an increase in mitochondrial mass without removing some of your muscle, so careful thought needs to go into your testing protocol for the block. Aside from these issues, it could add a little more variety to your training during the off season and give you great level of base conditioning on which to build towards your competitive season.