Q: Throughout the summer I’ve focused on Lactate Threshold interval training. What is the best way to continue the interval training as we transition into the fall/winter season? Should the focus go towards VO2 Max intervals? Should the overall “on” time decrease or maintain steady?
A: This is a very complex question to answer due to the confusion around the definition of lactate threshold, its purported benefits and costs of this method of training when contrasted to the potential benefits of other forms of training. In my opinion many of the often stated benefits of this type of training are not amply proven in science.
In my experience and in the majority of current research what we once thought of as the benefits of this type of training are in question. I believe there is some value in this sort of training in early periods of the training year, and for long distance races where the primary benefit of this type of training is on efficiency or economy. While there is no doubt that virtually all training can have some positive effects for endurance sports we should consider a cost benefit analysis. In other words minimizing the cost and maximizing the benefits. In the case of threshold training due to the required duration of training and with less than optimal benefits the cost is quite high.
So the time to start with VO2Max Intervals is now. I recommend that you start conservatively, one session per week to ten days depending on fitness level and not more than 5-10 minutes of hard work time. Then over time you can first increase the volume of intervals in each session, followed by increasing the number of sessions. We have also found that for those not used to doing these type of intervals it can be a bit easier to learn how to do them effectively by starting short, 30 seconds on/30 seconds off and gradually building the duration over several weeks. It is important that for these intervals to be optimally effective that they have to be done very hard, 90-95% of maximum heart rate. You heart rate will not get to that level as it takes the heart rate and oxygen deliver systems some time to ramp up to meet the energy demands. A good pacing strategy for these it is think of doing these at a pace you could sustain for 4-6 minutes and after a couple of minutes of intervals you will be right in the desired range.