Phase-Specific Testing: Nov ‘22

Hey, it’s Tom and Emma.

We both hope you’re having a great week and have been getting in some solid riding time.

Over the years, we’ve had a lot of requests that we send out more training tips via email and so we’ve decided to start a monthly newsletter 🥳

This will include a round-up of our latest training/coaching tips, a summary of recent scientific literature that’s caught our eye, and any other news that we think you should know about. 

One of our passions is providing resources and knowledge to help self-coached athletes improve their cycling performance, so we’re excited to start sharing these regularly. 

Here’s the first instalment…

Musings

One thing we’ve been talking a lot about lately - both among ourselves and with our clients - is the concept of ‘phase specific testing’. 

This is the idea that you need to choose the right types of testing to align with your training goals. 

Sounds pretty obvious, but it’s actually rarely done!

If we consider the current time of year, most athletes will be taking a bit of an off-season break right now, and then looking to begin rebuilding their aerobic base through the winter. 

Some of the key goals through this period will be to improve fat oxidation ability, and build endurance/fatigue resistance, mainly through a high volume of low- and middle-intensity riding. 

However most athletes (and indeed many coaches) will revert to the standard FTP test to assess progress through this phase. It’s a trap that’s very easy to fall into! Yet FTP is typically not something we’re seeking to develop through this phase. 

Indeed, improvements in FTP through the winter period can, in some cases, be a bit concerning, as this might indicate we’re doing too much intensive training too soon, and may lead to a burnt-out athlete when the spring and summer come around.

Better testing protocols for evaluating progress through this phase would include the ‘talk test’, which assesses the ‘first ventilatory threshold’ (sometimes known as the ‘aerobic threshold’). We write about this test here, and improvements in this parameter can tell us a lot about improvements in endurance and fat oxidation abilities. 

Another option would be to perform what we refer to as a ‘fatigue resistance test’, where you perform an all-out maximal effort towards the start of a ride (let’s say a 60 second effort). Then you ride for 2-3 hours at a Zone 2 intensity. And finally you repeat this maximal effort again, to see how much your power drops off between the ‘fresh’ effort and the ‘fatigued’ effort. In many cycling disciplines, the ability to produce high powers under conditions of existing fatigue (like at the end of a race) is far more important than the ability to produce hard efforts when fresh. So this is a great parameter see improvements in!

After a 12-week period of working on aerobic base and endurance with one of our athletes, we were able to see some pretty clear improvements in fatigue-resistance using this testing method. The drop in this athlete’s 60S power after 2H of Zone 2 riding went from 19% at the beginning of this training phase, to a mere 7% at the end of this phase. 

Importantly, there was no change in the athlete’s FTP, or ‘fresh’ 60S, 5M and 20M powers. Yet, the athlete was performing better in races (particularly longer road races and stage races), underlining both the importance of picking the right type of testing, and not just chasing improvements in FTP!

We write a lot about different testing protocols on our website, so be sure to check out some of our articles if you want to learn more. We’ve also recently updated all of our pre-built training plans to make sure we’re including the most relevant and up-to-date testing methods. 

Science

On a related topic to our musings above, we came across this recently-published paper, which we thought raised some interesting learning points: 

Prolonged cycling reduces power output at the moderate‑to‑heavy intensity transition

Quick Synopsis

This study looked at whether the first ventilatory (VT1) is reduced following several hours of Zone 2 riding.  VT1 is a key metabolic transition point that defines the top end of Zone 2 in a 6-7 zone system, or the top end of Zone 1 in a 3-zone polarised model. Having a high VT1 is a strong marker of endurance. 

Methods

This study involved 14 endurance trained cyclists and triathletes (13 male), VO2peak 59.9 ± 6.8 mL/kg/min, training volume 9 ± 3 h/week.

Participants completed a ramp test, then rode for 2H @ a Zone 2 intensity (90% of VT1), and then completed another ramp test. The tests were terminated after a fixed duration, and thus participants were not required to continue to the point of exhaustion in either ramp test. 

For each ramp test, the first ventilatory (VT1) was determined from expired gas.

Key Findings

The researchers found a statistically significant reduction in power at VT1 after 2H of Zone 2 riding. The reduction in power averaged 21W, which was a 10% decrease. 

This drop was partly, but not completely explained by a drop in cycling efficiency (i.e. an increase in the amount of energy required in order to produce power on the bike). It appears that this was a result of a switch to increased fat utilisation over time, which is a less efficient, but more sustainable way to produce power compared with carbohydrate oxidation. 

Strengths & Limitations

• There are some limitations in relation to the statistical analyses used. We won’t go into the details, but the key take-home is that the methods used can give rise to a higher than expected rate of ‘false positive’ findings, so we need to interpret the results with some caution.

• The athletes included in this study were all moderately-trained athletes. We suspect that well-trained cyclists would have a smaller drop-off in VT1 power, and that less well-trained cyclists would have a higher drop-off.

Key Take-Aways

1. Fatigue-resistance testing is important

This study provides data to support the use of ‘fatigue resistance’ testing in cycling, as suggested in our musings above. How well you can maintain your VT1 power, or produce supra-threshold power outputs after several hours of riding is very important across a range of cycling disciplines. 

2. Monitor heart rate and breathing to avoid unplanned fatigue

This study also suggests that, if you’re riding for an extended period, you may inadvertently cross VT1 into Zone 3 if you’re only riding to power, and not paying attention to other physiological markers such as heart rate and breathing. 

In some instances, stepping into Zone 3 is ok and indeed might be a goal of the session. 

However, if it’s important that a session doesn’t result in a high level of metabolic/physiological stress or fatigue, it might be worth also keeping an eye on heart rate and breathing rate, and making sure these parameters aren’t rising significantly. 

In this study, the 21W drop in VT1 power was associated with an increase in heart rate of around 9bpm on average, which should give you an idea of the magnitude of HR drift you should be looking for.

However, interestingly, three of the 14 participants actually had a drop in heart rate as the ride went on, so this variable clearly isn’t always reliable..! We suggest making sure your breathing rate also always remains very comfortable (so that you could hold a conversation easily), if you’re looking to minimise fatigue. 

News

• We have changed the way we sell our pre-built training plans, which has allowed us to substantially reduce the price! 8-week plans are now $25, and 16-week plans are $45. Check out our new training plans page here.

• We also have a new and improved critical power calculator on our website, which allows you to input your testing results directly on our site, rather than having to download a spreadsheet. Check this out here.

• Finally, we now have a podcast called ‘Explaining Training’. The goal is to provide succinct answers to common training questions. You can find the podcast on Apple Podcasts, Spotify etc. If you like it, do feel free to subscribe and leave a review.

That’s all for this month. If you have any feedback or comments, do get in touch at info@highnorth.co.uk. 

As always, you can find all of our available products and services on our website, including our physiology guide, and workout library. 

Thanks,

Tom & Emma