General preparation (2) for the 2021 race season

In January I shared the details around my first 10 weeks of training towards the 2021 race season. In that post I wrote about my starting point, the tools I would be using to measure progress (HRV4Training), I provided an update with details on my training, and I set out some thoughts about what this phase would look like.

Since that update I have continued to make progress with an extension to the initial general preparation phase. I have enjoyed this training period tremendously and I feel like I have established a solid routine and process for base training that I can use in future off-seasons. In this post I'm sharing an overview of the last five weeks of training since my previous update.

A three-day microcycle

As I mentioned previously, I shifted from a two-week training cycle to working in three-day cycles. Every three days I did a high intensity session with a strength session later in the day. The two days following that hard day were lower intensity, although still fairly high volume to help build my aerobic base. Each three day cycle I focused on a different intensity on the hard day: VO2 Max, lactate threshold (LT), or steady state (SS) training. Every two, three-day cycles I would include a longer run the day after a hard day - this meant doing a long run every 6 days.

The key sessions that I completed during this phase were:

• VO2 Max: 5x1km; 5x3' uphill; HIDIT
• Lactate threshold: 4x6'/2'; 4x7'/2'; 20x1'/1'; 5x5'/1'
• Steady State: 3x15' uphill; 3x20' uphill

Each week I gradually increased my weekly mileage and training duration with the majority of training in Z1 and Z2. A big focus for this period was to do as much aerobic training as I could handle so I spent a lot of time in these lower zones just cruising and getting the miles in. This meant that the two days after a hard day were relatively easy in terms of intensity, but still quite demanding in terms of training volume.

The value of HRV Logger and DFA1a

One of the refinements I made towards the end of the first general preparation phase was to adjust my training zones using HRV Logger and the DFA1a method of determining aerobic threshold. At first I found this pace to be very slow and it necessitated walking on some of the hills. I wasn't sure how much confidence I had in this value as the heart rate threshold for the top of Z2 was much lower than I had been using previously.

I shifted my Z2 heart rate down from 140bpm to 125bpm based on the following three trials. The first is at 135bpm, the second at 130bpm, and the final at 125bpm. Only at 125bpm did I manage to achieve a DFA1a below 0.75 for the entire run.

Three HRV Logger sessions: with a max HR of 135bpm, 130bpm, 125bpm.

While I have been very conscientious of many of the factors required to achieve consistency in my training routine, I believe that this new Z2 threshold and the intensity control required to run at this effort allowed me to increase my volume effectively each week. Over the last 7 weeks I have found myself running 5-7' faster on 10km routes than I did in the first runs using these new zones. In addition, I have felt stronger, more comfortable and smoother in my stride at the end of longer runs which stay under this new threshold.

I still have more testing to do but based on this initial trial I'm very pleased with this method of determine my aerobic threshold.

Progress to date

In a continuation of my base period of training I have been consistently increasing my weekly training duration over the last five weeks. However, I did see one period where I had two consecutive HRV readings lower than my normal range. As a result of these lower readings I took three lighter, low-intensity days. You can see the two yellow bars in the top chart in the following image and the corresponding decrease in acute training load where I took some easier days in the chart below that.

HRV daily measurements and training load metrics.

In terms of freshness over this period, I was definitely not feeling fresh as I could feel the daily volume and accumulated mileage. Fortunately the guidance in HRV4Training Pro recognised this and provided a useful warning:

Recently you have been increasing training load consistently. As expected, freshness is going down. That's fine if planned, but keep an eye on your injury risk.

My injury risk remained low, so the only issue here was a deliberate accumulation of training load. I believe that the low injury risk was due to slowly increasing my training load and also the discipline I maintained in the training intensity. You can see these two measures in the charts below.

Freshness and injury risk metrics.

Finally, a very interesting shift that I noticed when putting together my data for this blog is my aerobic efficiency. In the past I haven't looked at this very closely because it can be affected by the amount of vertical gain and also the surface I run on. However, this winter I have been running mostly on the road and I've been trying to run more flat routes so I don't have to walk to stay in Z2.

In particular, I was very pleased to see that from the point I started using my new Z2 threshold as measured by HRV Logger (from around mid-January), my aerobic efficiency has been gradually increasing. I think this is a good sign and a useful way to justify the new DFA1a measurement for aerobic threshold. You can see the increase in aerobic efficiency in the second half of the following chart.

Aerobic efficiency.

What's next?

The next training phase will be a specific preparation phase. This means I will be looking to align my high intensity sessions with the demands of the races I'm doing this season, that I will start to include more vertical gain over the training week, and that I will prioritize performing well in specific sessions rather than prioritising aerobic training volume. I anticipate that this phase will last about 10 weeks and will lead into my first race of the season in May.