As a cycling coach, during the COVID-19 quarantine many cyclists find themselves searching the internet for training advice, they'll soon realise there is a lot of conflicting thoughts about the most effective training strategies. The majority of amature cyclists follow the traditional school of thought with long hours on the bike and frequent tempo or sweet-spot sessions. However, polarised training, including high-intensity interval training (HIIT) is the training strategy that is most popular among professional endurance athletes and coaches. Polarised training refers to the idea of a training mix between very hard and very easy. Different coaches will have different views as to which mode of training is more effective, a recent scientific study by Neal et al. from the University of Stirling in Scotland seems to have finally settled this debate once and for all. This study is one of the most comprehensive and most well-designed of its kind and may finally be able to accurately answer our question as to which training model gives us the greatest gains.
The study by Neal et al. compared predominantly tempo training (moderate intensity) to high-intensity interval training (HIIT) in a randomised cross-over study. Fortunately, the participants of this study were well-trained cyclists and performed 6 weeks of HIIT and 6 weeks of tempo training (in a randomised order), separated by a 4 week detraining period in order for performance measures to return to baseline. The training load during the 6 weeks of either HIIT and tempo training protocols was matched. Before and after each 6 week training block, all participants completed a 40km time trial, a peak power output test and a test to measure high-intensity capacity. Although performance improved following both training protocols, the HIIT protocol outperformed the tempo training protocol on all performance measures.
The polarized group achieved greater performance development across all tests but power at 2 mmol/L lactate.
VO2 max increased by 11.7% in the polarized group. By comparison, the threshold group results were actually minus 4.1% !
Power at 4 mmol/L lactate (approximate threshold power) improved by 8.1% in the polarized group. This in contrast to the 1.4% threshold groups.
Power at 2 mmo/L lactate (below threshold power) The improvement in the polarized & threshold groups and was 9.3% & 2.0% respectively.
Identifying the various lactate metrics through testing is crucial to avoid wasting time training at the wrong intensity, that is why we use the INSCYD lactate testing protocol. In the case of most amature cyclists avoid prolonged periods of zone 2 training which does not offer the correct intensity for endurance or the intensity for physical adaptation seen at LT2 or above.
What training did the polarised / HIIT protocol entail?
The study ensured that during the HIIT period, the participants completed 80% of their time at a low intensity and 20% of their time at high intensity. Note this is time not volume, volume would be nearer to 10 %. The high intensity time was accumulated while performing 6 x 4-minute intervals with 2-minute rest periods. During the rest periods participants either pedaled backwards or stopped pedaling altogether.
How do I apply this to my own training?
Excellent results can be achieved through following a polarised program on only approximately 7-8 hours per week. When training for 7 hours per week, it is recommended to spend approximately 60 – 90 minutes (20% of training time) training at a high intensity. When completing intervals in zone 5 is pretty much as hard as you can possibly go for the allocated time. I suggest my clients perform two HIIT sessions per week, if done correctly (and to the prescribed duration) that's all you need to. But the are HARD sessions and you must allow adequate recovery between sessions.
Does this apply to me if I’m training to race after the quarantine?
Assuming you are able to race this year, the last 4-6 weeks prior to your event (excluding a taper) should include HIIT. As shown in the study, polarised training resulted in far greater 40km time trial results compared to the tempo group. So even when measuring performance in longer performance tests closer to tempo/moderate intensity, the HIIT protocol was still superior. It is however important to reduce total weekly training time when performing HIIT. Doing high-intensity training between long training rides will result in you becoming fatigued and not adapting optimally to the HIIT. My recommendation is make the focus of your training time during the quarantine around 70% heart rate max or 65% VO2 max mainly, which will maintain current fitness levels and provide a good fat burning for those extra calories. The rest of your time can include the FTP (LT2) and above intervals, for example 4 x8m @ 110% (2m rest at 50%). What I don't want you to do is smash yourself on Zwift every day, it's very easy to get carried away.