VO2 Phase

Monday signals the start of my next phase of training. I have called it my VO2 Phase to highlight the key hard session. Lasting 4 weeks the phase has two main goals:

1. Increase maximum oxygen uptake (VO2max)
2. Extend aerobic endurance

Naturally this will be balanced out with work in strength, technique, plyometrics, flexibility and other areas as applies in all phases of training, but the emphasis will be on the two goals listed above.

Over the next 4 weeks my training cycle will be 6 days. This is partly dictate by my work roster and current recovery capabilities. I will be working three shifts of 12 hours followed by three days off. My training roster will be:

• 1.5-2hrs easy. Work
• Bike or Run VO2. Work
• Swim Hard. Plyometrics. Work
• Bike 100-130km
• Swim 3000m. Brick 2-4 hours
• Run 2:45. Weights

Further easy aerobic work will be incorporated around these key sessions depending on time and recovery. This extra work will be commuting on the bike, recovery swim or 1hr run. If I am struggling, this extra work will be dropped.

VO2max dictates the upper limit of aerobic performance as discussed in my last post. Therefore, it is important to do some work aiming to maximise this element of endurance performance. To increase VO2max, training typically involves repeated efforts at around a work rate that elicits maximal oxygen uptake. This is high intensity work. There are a number of different protocols to choose from that all have some reasonable evidence to support effectiveness. Because the intensity is high, and work rates will also involve a fair anaerobic contribution to maintain this rate, there is a risk of inducing an early peak and/or injury. As a result the method I have chosen may not bring about the fastest or greatest increase in VO2max, but I do consider it more appropriate in regard to the above concerns.

My approach will consist of one focused set every 6 days for the legs, alternating running and cycling. My harder swim session each week will incorporate some work at VO2max paces, exactly how much will depend on how well I can hold my technique together. The timeline fits into my observations that I am currently responding very well to high intensity training that isn't conducted too close together. Six days between VO2max training appears to be optimal. There isn't a need to include both running and cycling in each 6 day cycle as the aim is to improve the central components. That is, improve the ability of the cardiorespiratory system to transport oxygen to the muscles, rather than peripheral aspects at this stage. Alternating running and cycling will also allow adequate muscular recovery so that maximal benefits can be achieved from the longer endurance training.

What is involved in a VO2max training day?

4-6 intervals of 3-6 minutes performed at an intensity near VO2max, with 3-5 minutes active recovery. This intensity will generally give a heart higher than 90% HRmax, and in terms of running will be somewhere between 10,000m and 3,000m race paces.

4-6 x 3-6min @ 90-95%HRmax (3-5min recovery)

The aim is perform each interval at a work rate that will require near maximal oxygen consumption. The length of the intervals provides an appropriate time frame for the aerobic system to reach a so-called steady state. This will force the body to adapt by increasing cardiac output to meet the demand of exercise. Because there is also an anaerobic contribution at this work rate, the trick is pick a pace that achieves maximal oxygen uptake, but is not so fast that lactate accumulation forces premature fatigue. The extended recovery time will ensure muscle lactate can be removed prior to the next interval in order to prevent premature fatigue. The focus is aerobic capacity training, not anaerobic capacity or tolerance.

I do not have access to the an exercise laboratory for testing. Therefore I do not have the ability to directly test my VO2max. So how will I monitor improvement? The short answer is that I will basically have faith in the training. While I won't be directly measuring VO2max, I will expect to see the following signs to indicate likely improvement:

• Reduced resting heart (due to increased cardiac output)
• Faster speeds at submaximal heart rates or lower heart rates at submaximal speeds
• A feeling of efficiency or ease in shorter aerobic sessions

My second goal for the period is to extend aerobic endurance. I will make a concerted effort in each discipline to perform a long session at 60-80%HRmax. Long runs will be for 2:45, cycles will be 100-120km and the long swim will be 3000m straight plus additional technique work. In short the idea is ensure the body can cover the distance, enhance fat metabolism and develop important adaptation such as increased mitochondrial and capillary denisty. After all, if you can't cover the distance, there isn't much point in doing the higher intensity work when it comes to race day.