Paper Review: How Do Olympic Endurance Athletes Peak For A Gold Medal?
We find the study below incredibly insightful. It’s very rare to get such a detailed glimpse into the training practices of the world’s best athletes, and there are numerous nuggets of information that can be gleaned from the study! Our own thoughts and take-aways can be found towards the end of the article.
The Study
Quick Synopsis
This study analysed daily training data from 11 Norwegian XC Skiers (4 male, 7 female) during the year leading up to their most successful gold medal-winning performance in the Olympics or World Championships.
The study looked in detail at how the athletes periodised their training across the year, as well as how they tapered for their key event.
Methods
All 11 athletes recorded day-by-day training data across a whole year leading up to their gold medal-winning performance.
The training was classified as either ‘strength’, ‘endurance’ or ‘sprint’ training. Strength training was performed in the gym. Endurance training included both low intensity and high-intensity interval training and included skiing, roller-skiing, running and cycling. Sprint training was very high-intensity ski-specific training.
The athletes recorded the amount of time spent in each of 5 different training intensity zones, where zones 1–2 were below the first lactate threshold (LT1), zone 3 was between LT1 and the second lactate threshold (LT2), and zones 4–5 were above LT2. (For an explanation of these lactate thresholds, see here).
The training year was divided up into three key phases:
General Preparation Phase: 6-10 months out from main competition (e.g. Olympics)
Specific Preparation Phase: 4-5 months out from main competition
Competition Phase: 0-3 months out from main competition
This allowed the researchers to look at patterns in how the athletes’ training changed over time.
The researchers also specifically looked at the ‘Peaking Phase’, during the 6-weeks prior to the main competition.
Key Findings: Annual Periodisation
The athletes trained between 700-900 hours/year. This equates to roughly 13-17H/week on average and supports the widely-held view that volume is one of the major determinants of performance in endurance sports.
The athletes employed a polarised intensity distribution, with 77+/-2% of endurance training sessions being low intensity (Zones 1 and 2), and 23+/-2% of endurance sessions being higher intensity (Zones 3-5).
86% of all endurance training time was spent in Zone 1 - a lower intensity than may have been anticipated! We’ll discuss more about this below.
Training became increasingly more polarised as the year progressed. For example in the general preparation phase, athletes spent an average of 36-mins/week in Zone 3, whereas in the competition phase, they spent just 18-mins/week in this zone. Conversely, weekly Zone 5 time increased from 12-mins/week to 30-mins per week between the general preparation and competition phases respectively.
Strength training was performed 2-3 times per week during the general and specific preparation phases, but not at all during the competition phase.
The volume of training was highest in the general preparation phase, as illustrated in the chart below. However, interestingly, the volume of sport-specific training was highest in the specific preparation phase.
Key Findings: Peaking Strategies
During the two weeks leading up to the Olympics/World Champs, the athletes did the following:
Reduced their training volume on average by 4% and 15% during days 14-8 and 7-1 vs the preceding 4 weeks. However, there was large variability. Indeed, 4/11 athletes increased volume during the last 7 days leading up to their main competition!
Maintained the number of training days per week. In other words, the athletes did not take extra rest days compared to normal.
Reduced the amount of low-intensity training and increased the frequency of higher intensity sessions (zones 3-5), particularly for Zone 5 sessions. Although the frequency of higher-intensity training was higher, each high-intensity session was typically shorter than in the general preparation phase, meaning the total volume of high-intensity training was not notably different.
Included more frequent bouts of anaerobic sprint training on the skis.
The frequency of rest days and higher intensity training (HIT, Zones 3-5), is shown in the chart below. Key points of note are that 10 out of 11 athletes performed a HIT session within 48 h of competition, and only 3 athletes took a rest day during the last 5 days before competition.
Strengths and Limitations
The key limitation of this study is that it was ‘observational’. This means we don’t know if the strategies adopted by the athletes were the best possible strategies they could have used, because there was no comparison between different strategies under controlled conditions to prevent bias. However, since all the athletes won gold in their target competition (either the Olympics or a World Championship), we do know that the strategies adopted can’t have been too detrimental!
Another key limitation is that the athletes were, of course, very high-level. The training volumes that can be tolerated by these athletes, and the amount of time needed to recover from training is likely to be different from lower-level athletes.
Likewise the athletes were XC skiers, and not cyclists. Nevertheless, the physiological demands of XC skiing are remarkably similar to those of endurance cycling, so in our view, the transferability is good. The key difference is probably the amount of non-specific training the XC skiers perform in the general preparation phase. This is partly by necessity due to the weather conditions. For similar-level cyclists, there would most likely be less cross-training and more on-bike training during this phase.
All of the athletes’ data were self-reported, which could mean there’s a risk or inaccuracy. However, studies have shown elite-level athletes are very good at maintaining accurate training logs, so inaccuracy is probably not a great concern.
Our Take-Aways
While the key findings above are very interesting in and of themselves, we think there are some particular points of interest that we’d like to discuss more.
Take Care with Intensity
Firstly, it’s interesting to note that even though the athletes in this study were exceptionally well-trained and talented, they weren’t doing much more high intensity training than the average endurance athlete.
Through the majority of the year, the athletes were averaging around 2 higher-intensity sessions per week (which includes Zone 3 sessions). And across a week, they were typically spending between 15-30 minutes in each of the Zones 3-5.
The key differentiator between higher-level and lower-level endurance athletes seems to be overall training volume, rather than the amount or type of intensive training performed. This suggests that increases in low-intensity volume are tolerated much better than higher-intensity riding. Indeed, this is something we’ve observed through our own coaching. Over-intensifying training is often a fast-track for burn-out if continued over the longer term, even for very well-trained and talented athletes.
The exception to this rule is for time-crunched cyclists who have reached a plateau in their fitness. For this specific group of athletes, there may be some benefits to carefully increasing the amount of intensity performed each week (perhaps aiming for two sessions above threshold, and one session slightly below threshold each week, for example). This should be done carefully, ensuring there is still an appropriate amount of low-intensity training and enough recovery between harder sessions to allow adequate recovery and ensure the quality of these sessions is good.
Well-trained cyclists should scale back Zone 2
Secondly, it’s interesting to note that the majority of low-intensity training time was spent at a ‘Zone 1’ intensity, where lactate levels were below 1.1mmol/L.
On first glance, this seems to run contrary to the typical recommendation that endurance training should be done at a slightly higher Zone 2 intensity for greatest benefit, and that the main use of Zone 1 is for recovery purposes.
However, the athletes in this study already had a very highly-developed LT1. We can see this in the fact that, on average, the top end of the athletes’ Zone 1 sat at 73% of Max HR. For most mere mortals, 73% Max HR would be solidly Zone 2, and potentially even tipping into Zone 3, and lactate levels would typically be around 2-3mmol/L.
What’s more, it’s worth considering that although the XC athletes’ measured lactate levels were low, the rate of lactate production and degree of muscle fibre recruitment is probably relatively high, even at a low Zone 1 power. This is due to the high absolute power/speed sustained.
The reason these athletes are able to sustain low lactate levels despite high lactate production rates is because they are highly aerobically trained, and thus very good at clearing away any lactate that’s produced.
This is a point raised by Inigo San Milan in his interesting discussion of Zone 2 training and his experience coaching Tadej Pogačar. San Milan noted that the lactate flux of well-trained cyclists is very high and that, for the majority of training time, these athletes need to ride at a lower intensity than ‘normal’, based on lactate levels, in order to avoid accumulating too much metabolic strain.
In practice this means that well-trained cyclists might target roughly 50-65% FTP for their long endurance rides. In contrast, relatively novice cyclists might be better targeting something around 70-80% FTP, as their absolute power output is lower and they can tolerate riding at a higher percentage of their FTP with less metabolic and muscular strain. As females also produce lower absolute wattages relative to males, there’s a theory that they should also increase their intensity slightly for the same reasons.
Again, this is something we’ve noticed when coaching athletes across a wide range of ability levels; that the ‘traditional’ definition of Zone 2 riding needs to be iterated on an individual basis.
The ‘optimal’ taper often isn’t possible
In this study, it’s interesting that the athletes didn’t meaningfully reduce training volume over the two weeks prior to their main competition. This is in contrast to experimental studies, which tend to support a volume reduction of 50% over a period of around 2-weeks.
However, the athletes’ competition season was very densely-packed with races, and this probably prevented the athletes from following what would be an ‘optimal’ tapering strategy. Instead, the authors of the paper suggested that the athletes likely employed a series of mini-tapers before each competition.
This is a strategy we tend to use with our athletes during periods of intensive racing, in conjunction with so-called ‘block periodisation’ to provide a quick fitness boost between races. You can read more about this strategy in our popular Physiology Guide.
For most athletes, who are racing semi-regularly through the competitive season (e.g. every 1-3 weeks), we find the best practices for tapering are as follows:
Begin to reduce training volume over the 4-10 days leading up to your race. A reduction in volume of around 30-40% works well on average.
Maintain your normal training frequency. Don’t take extra days off the bike.
Avoid any non-specific training (e.g. strength training) in the week prior to your race.
Cut down on the volume of low-intensity riding, by shortening sessions, and keep these rides largely to a low Zone 2/high Zone 1 intensity.
Include 1-2 high-intensity interval sessions during your taper, targeting powers above threshold. These should be ‘abbreviated’ sessions - roughly 40-70% of your usual volume of high-intensity riding per session. One of these high-intensity sessions can be included 1-2 days before your competition, as this helps to prime your aerobic and neuromuscular systems for racing.
You’ll notice these best practices align closely with the strategies used by these high-level XC Skiers!
