What's Cool In Road Cycling

Toolbox: Seasonal Variability in Fitness?

As many Northern Hemisphere roadies are winding down their season and starting to make plans for the off-season, we at Toolbox are still going strong, with a series to make your off-season enjoyable and productive fitness-wise. First up, we investigate just how much your fitness should vary throughout the different parts of the year…

Farewell to Summer
Coming up this weekend is the fall equinox, marking the official end of summer and the beginning of autumn. I have no problems remember that summer is going if not already gone, as the campus floods again with hordes of new and returning students. I quite enjoy this time of year, as the students are keen and energetic, and somehow still all show up to my 8 am lectures!

Many of you are probably saying farewell to summer by riding your last big race or event of the season before going into semi-hibernation or transitioning to other forms of cycling or cross-training. For me, my last big event was this past weekend at the Highlander Century Tour in upstate New York, featuring >3,000 m of elevation gain spread over >20 significant climbs of up to 23.6%. A truly fun and epic way to say goodbye to the competitive road season!

School’s In
So summer is over and school’s back in, and the question becomes how do we make the coming off-season the most enjoyable and productive one possible from a fitness perspective? As always, there is no one single template for success. Some riders will be diving straight into hard-core cyclocross training and racing for the bulk of the winter, while others will take a more leisurely break and focus on cross-training. Still others will continue with road/trainer riding as their primary activity throughout the off-season.

There is no single right path, as we all have personal preferences and conditions/limitations. Personally, my non-cycling athletic passion is squash, a completely different sport from cycling in its reliance on running sprints and accelerations, angular movements, and racquet hand-eye coordination. Not necessarily highly specific in cross-transfer, but too much fun for me to ignore. However, my heart rate data certainly suggests that it forms an excellent way of gaining high-intensity cardiovascular training. As always, I will continue to commute and ride easy on the road as much as possible, supplemented by specific indoor trainer workouts. Finally, I will also be dabbling in the black art of cyclocross for the first time this year for something different.

Seasonal Fitness Changes?
Overall, it will still add up to a lot of activity and training, so no danger of turning into a sloth. That’s likely the case with many of us fitness junkies no matter what off-season path we choose. One recurring question over the off-season is just how much bike fitness is it OK to “lose” without severely compromising the buildup for the next season? Certainly Jan Ullrich epitomized one extreme, with the major drop in fitness and gain in weight necessitating a lot of extra time and effort along with risk of injury or overtraining just to get back to baseline, let alone building for a stronger season. At the other extreme, a fanatical devotion to maintaining a high level of specific bike fitness and optimum in-season weight throughout the off-season can be a difficult physiological and mental task, leading also to the path of overtraining and burnout.

Sassi et al. 2008
Such a question of optimal off-season fitness is obviously difficult to manipulate in real-life settings, so the closest approach is to determine the seasonal changes in aerobic indices in real athletes. In this case, the ideal is to study professional athletes to get the best idea of what seems to currently work for the top athletes.

This approach was performed by Sassi et al. in a 2008 article in the journal Applied Physiology, Nutrition and Metabolism the journal of the Canadian Society for Exercise Physiology. Taking a group of top professional road and mountain cyclists, Sassi et al. tracked not only their VO2max over the course of a year, but also other important aerobic measures such as gross efficiency and economy.

Therefore, the study had two objectives:
1. Determine the seasonal changes in aerobic indices.

2. Determine the relationship between VO2max, gross efficiency, and economy. Gross efficiency (GE) is defined as the ratio of work performed to energy expended (by definition, this can be measured over a range of workloads from very light through to maximal sprints), while economy (EC) is defined as the rate of oxygen uptake at a set submaximal workload.

Some notes about the study methodology:

• Subjects were not just highly trained amateurs or even “run of the mill” professionals, but those at the top end of the sport. Three of the eight road cyclists had finished top 5 in either the Giro or the Tour, and four of the five mountain bikers were current members of the Squadra Azzura.

• Subjects performed two tests in each session. The first was a 12 min effort at a constant workload to determine economy and efficiency. After a break, VO2max was determined using a typical incremental protocol.

• Tests were performed on all subjects. However, Objective #1 above was only tested on a subgroup of 8 subjects, consisting of the 5 mountain bikers and 3 roadies. All athletes had the same coach.

• For seasonal variability, the three testing sessions occurred in December (REST), March (PRE-COMP), and June (COMP).

• The constant power test were performed at approximately 70% of peak power output (PPO), which resulted in actual or predicted exhaustion at about 10-20 min during the REST session. The same workload was used for the subsequent tests.

• Tests were performed on a calibrated SRM laboratory cycle ergometer.

No surprises that the power outputs were much higher than what we as typical amateurs can generate. This use of highly trained and elite professionals was the correct approach, as the entire goal is to study the top athletes, who we may assume to have “optimized” their training, to see how it might apply to less elite athletes.

• VO2max increased significantly from off- to in-season, from 69.4 to 74.2 and 76.7 ml/kg/min during REST, PRE-COMP, and COMP.

• This was matched by increases in peak power output, from 6.3 to 6.8 and 7.0 W/kg during the incremental test.

• Performance with the set workload test (70% of initial peak power output during REST) also improved, in that the predicted tolerance time increased dramatically from 17 to 30 and 46 min.

• However, despite the improvements in VO2max and tolerance times, the two efficiency measures did not change over the course of the year. On average, the subjects were operating at an economy of about 75-78 W for each 1 litre of oxygen consumed. Similarly, this worked out to a gross efficiency of 21-22%. That is, even these highly fit and trained professionals were using only about 1/5 of the energy they were burning to move the bike forward (yes I know it’s a stationary bike, so there’s not much actual moving!).

• One interesting note with the gross efficiency is that there was much higher variability during the REST session compared to PRE-COMP and COMP. That is, the eight subjects all fit into a very narrow range of values (21-24%) during the latter two tests, but these same subjects had a much wider range (19-25%) during the REST session. So it may be the case where averaging results into a group mean unintentionally hid some interesting results. Namely, it may be the case that efficiency does indeed change much more in individual athletes than the group averages suggests. For example, one athlete went from an efficiency of 19-22% between the REST and PRE-COMP sessions.

Rubber on the Road
So in summary, it appears that even highly trained and successful professionals do indeed “let themselves go” a little bit aerobically during the off-season, to the tune of letting their maximal aerobic capacity decrease by about 9% during the off-season compared to the competitive season. This finding is important in that it lays to rest any fears that any and all lowering of aerobic fitness is a bad thing. Considering their highly fit status, this would suggest that typical amateurs can afford to decrease their aerobic capacity by as much as 15% during the off-season. That time and effort can be spent instead on core training, working on bike-related skills, or simply having a mental break and having fun.

Given the caveat that gross efficiency during the off-season may actually decrease quite a bit, this may also suggest that skilled cyclists can quickly “re-learn” how to ride a bike very efficiently. However, keep in mind that these are professionals who ride their bikes an enormous amount during the year, and this rapid re-adaptation may not apply to those of us on limited training time. So it likely remains important to maintain some contact with the bike throughout the off-season.

Have a great start to your off-season, and look for more off-season related articles in the coming months in Toolbox!

Sassi, A., F.M. Impellizzeri, A. Morelli, P. Menaspa, and E. Rampinini. Seasonal changes in aerobic fitness indices in elite cyclists. Applied Physiology, Nutrition and Metabolism. 33:735-742, 2008.

About Stephen:
Stephen Cheung is a Canada Research Chair at Brock University, with a research specialization in the effects of thermal stress on human physiology and performance. He can be reached for comments at [email protected] .

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