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Maximising Cycling Fitness

Written by Paul Cadman | May 6, 2024 11:08:03 PM

Recently, all of us have been adapting to a new way-of-life and training in the midst of the COVID-19 restrictions, here in New Zealand and around the world. The restrictions have may have freed up training availability for some, but for many others, particularly those looking after children whilst working from home, the restrictions have become a new barrier to training and training well. Regardless of their effect on time available for training, the restrictions have altered everyone’s training modalities in some way, with long outdoor rides, runs in the bush, or outdoor races no longer on the menu. In this blog, I will describe the training Paul has been doing during the lock-down period in New Zealand, and the success we have been able to have through solid consistency despite a modest overall training volume.

By way of background, Paul came into the lock-down on the back of a well-earned break from training after a successful Coast to Coast campaign in the first week of February. Paul had been planning to do some aqua-bike racing at the end of the year, but, with the uncertainty we are all facing with COVID-19, we thought it best not to begin any specific build-up to these races just yet. Instead, the lock-down period seemed like a good time to go through a short training cycle focused on (i) re-establishing a training routine and (ii) building aerobic capacity at the top-end. Achieving these goals would form a good base to push on from should racing at the end of the year become more likely.

The training intervention

The lock-down cycling training intervention itself lasted six weeks, with the first simply focused on getting back on the bike and pushing the pedals, and the subsequent five weeks following a little more structure. Paul was generally limited to a maximum of ~8-10 hours per week, all on the trainer. Whilst we focused the intervention on polarising our training intensity distribution – that is, doing the bulk of the work at low-moderate intensities below the aerobic threshold – we included a structured high-intensity interval Zwift training workout in each week, along with a Zwift race. Zwift racing has proven to be a fantastic tool to keep training fresh, particularly in this lock-down period while we are all stuck inside.

The low-moderate-intensity sessions were programmed using a combination of heart rate (typically below Paul’s previous laboratory-based estimate of ~130 beats.min-1 at the aerobic threshold) and/or power (typically below our conservative estimate of ~180-200 W). In these sessions, we included some specific cadence work, with intervals of lowered cadence (~85 revs.min-1 down to ~65 revs.min-1). These functioned well to break up these otherwise potentially quite dull sessions, and also mimicked outdoor uphill riding, with higher forces and lower velocities required for the same power output. The training weeks were successfully dominated by low-moderate intensity work, with ~65-70% of total training time spent at power outputs below our rough estimate of Paul’s aerobic threshold in the first three weeks, before a decrease in this percentage as we sought to expand the time spent at the top-end later in the programme (here closer to ~50%). Whilst these percentages are somewhat lower than I would recommend for a standard training programme (2, 5, 6) (geeks see Prof. Stephen Seiler lecturing on this here: https://www.youtube.com/watch?v=MALsI0mJ09I), the lack of long outdoor riding meant that total training volume and load was still down on what Paul could reasonably handle (Figure 1). When we get back outside and push weekly training volume up to ~12 hours.week-1, we’ll be looking to have this low-moderate intensity work accumulate ~75-80% of total training volume.

Fig 1. Training load (TSS) and volume (h.week-1) across Paul’s five semi-structured weeks of ‘quarantine’ training.

 

In the structured interval training sessions, I was looking for Paul to accumulate as much time as possible at power outputs above our estimate of his anaerobic threshold, or maximum workload at which a metabolic steady-state can be achieved. To do this, I chose short interval, short recovery protocols similar to what is being researched in great detail by Bart Rønnestad’s group in Norway at the moment (1, 3, 4) (geeks see Prof. Rønnestad’s lecture on interval training in elite endurance athletes at the European College of Sport Science’s annual conference in 2017 here: https://www.youtube.com/watch?v=BpGesmNB9sI). Using a work interval power of ~320 W, I took Paul through a progression from four sets of eight repetitions of 20 seconds work and 40 seconds recovery in the first week, to five sets of eight repetitions of 40 seconds work and 20 seconds recovery in the fifth week (Figure 2). These sessions typically elicit a similar cardiovascular response to standard sets of 8-min repetitions, only with much more time spent at higher power outputs.

Fig. 2. This is the structured workout Paul successfully performed in the fifth week of the training intervention, at a session perceived exertion of 8/10. After a warm-up and a few primers, Paul completed 5 (8 x 40” at ~321 W, 20” recovery at ~128 W), with 3’ recovery between-sets. The manipulation of work and recovery intervals in this session meant that Paul could accumulate a much more substantial volume of work at power outputs higher than his anaerobic threshold (at least 50 W or so) - therefore providing a stronger mechanical and metabolic stimulus for adaptation - than if I had simply asked him to repeat longer, uninterrupted intervals at the same workload (321 W). This is shown in his heart rate data, where, after the first set, his average heart rate over the 8-min sets was 143-147 b.min-1 with a session peak of 154 b.min-1. This right around where his anaerobic threshold would typically sit (~145 b.min-1). So, we got a ‘threshold’ type cardiovascular response at supra-threshold workloads.

The results

In terms of the gains Paul made during this short training block, we saw some improvements at the top-end and in his lower intensity work. For instance, at the start of the programme, Paul did a 60-min spin, averaging 163 W and 130 b.min-1, with 9.5% W:HR drift. This drift figure means that, at the same power output, Paul’s heart rate was ~9.5% higher by the end of the session compared with the start. These numbers are pretty modest for Paul, and do perhaps reflect the break he had had prior to the lock-down! By the end of the programme, Paul did a similar session, this time averaging 198 W for only 122 b.min-1, with reduced drift (6.0%). These numbers probably reflect a sharp improvement in work output at the aerobic threshold – sustainable, “all-day” power – and significant cardiovascular adaptation to reduce the strain associated with a given workload. These are pleasing numbers.

At the top-end, we saw Paul’s highest 20-min power during Zwift races increase from ~268 W at the beginning of the programme to ~288 W by the end, a not-insignificant bump. Whilst raw numbers like this are probably best not compared between-races – given they are not time-trials and there is considerable inter-race variance in tactics and race management – these numbers indicate to me that Paul’s sustainable workload, or anaerobic threshold, probably has seen a nudge in the right direction. I’m looking forward to getting him back in the laboratory to see where this number actually sits!

Paul also did a ramp test at the end of the training programme, starting at 100 W and increasing in intensity by 20 W every minute until exhaustion, fatiguing after a minute at an average power of ~417 W. That is a pretty good number, and certainly a long way from where Paul had been just a few weeks beforehand.

 

What’s next?

The quarantine training I have described above has given Paul a considerable bump in his cycling fitness across the board, from “all-day” power at the bottom end to sustainable workloads at the top. Enthused by the good work he has done, Paul has now signed up for the New Zealand Road Race Nationals in July. That gives us nine training weeks to get the most we can out of the event.

We have devised the goals of this training period using Paul’s experiences on his trainer during the lock-down. Again, Zwift racing has proven to be very useful, as Zwift races are essentially truncated road races. In the ‘B’ category, Paul has found that his punch off-the-line is one of the main factors holding him back. Road racing is a fascinating event to prepare for, with the stochastic intensity profile requiring a cyclist to have a solid engine in order to recover well during periods of lower power in the bunch, such that they have access to huge outputs over short periods (<2 min) for breaks, and capacity to sustain high outputs for prolonged periods (>2 min) in breakaway and chase groups.

Accordingly, we have divided this training period into three, 3-week cycles, each with two hard ‘build’ weeks followed by a ‘deload’ week of reduced load. We are going to build sessions that focus on that top-end ‘punch’ in the first cycle, followed by sustained power and durability work in the second, and finally some race-specific sessions and a taper in the third. Exciting times!

 

References

1.       Almquist NW, Nygaard H, Vegge G, Hammarström D, Ellefsen S, Rønnestad BR. Systemic and muscular responses to effort-matched short intervals and long intervals in elite cyclists. Scand. J. Med. Sci. Sport. (2020). doi: 10.1111/sms.13672.

2.       Neal CM, Hunter AM, Brennan L, O’Sullivan A, Hamilton DL, DeVito G, Galloway SDR. Six weeks of a polarized training-intensity distribution leads to greater physiological and performance adaptations than a threshold model in trained cyclists. J Appl Physiol 114: 461–471, 2013.

3.       Rønnestad BR, Hansen J, Nygaard H, Lundby C. Superior performance improvements in elite cyclists following short-interval vs effort-matched long-interval training. Scand. J. Med. Sci. Sport. (2020). doi: 10.1111/sms.13627.

4.       Rønnestad BR, Hansen J, Vegge G, Tønnessen E, Slettaløkken G. Short intervals induce superior training adaptations compared with long intervals in cyclists – An effort-matched approach. Scand J Med Sci Sport 25: 143–151, 2015.

5.       Seiler KS. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform 5: 276–291, 2010.

6.       Seiler KS, Kjerland GØ. Quantifying training intensity distribution in elite endurance athletes: Is there evidence for an “optimal” distribution? Scand J Med Sci Sport 16: 49–56, 2006.