Category Archives: cycling anatomy

IronMan not enough for you?

Most everyone has heard of the Iditarod – the famous 1100 dog mushing race from Anchorage to Nome Alaska.  I recently returned from Alaska where I learned of the “Iditarod Trail Invitational“, tagged the longest winter ultra race in the world.  You have two routes you can follow, a 350 mile and the original 1100 miler.  The main difference are the modes of transportation.  You can race on bike, snowshoe or on foot. And it’s held in March where you it can be 30 degrees below zero with blistering winds.  There are sometimes days between rest cabins or villages so you have to carry a sleeping bag and food with you.  Visit the website here to learn more about it and read some of the competitor’s blogs.

How about the “Great Divide Race” which follows the US Continental Divide for  2,490 miles of cycling?

How about a Deca IronMan with a 24 mile swim, 1120 mile bike and a
262 mile run
?  Here’s their website.

Having never attempted one but from what I can gather, finishing depends a great deal on your mental fortitude; how tired you feel, how exhausted you are, and how the cold and hot plays games with your mind.

Assuming a high level of fitness and training, part of these finishes might be determined by nutrition – have you practiced your nutritional in take on road and in all sorts of weather.  Which leads me to this excerpt reprinted with permission by Human Kinetics.  The book is “Endurance Sports Nutrition“, by Suzanne Girard Eberle.

“The biggest danger with multiday rides, runs, treks and tours, cycling classics, sports camps, and climbing expeditions is incomplete recovery—

you slowly become glycogen depleted as each day passes and thus become increasingly fatigued. You find yourself less and less able to respond quickly or maintain your desired pace, and mentally you find that your commitment and enthusiasm start to wane. (Of course, chronic fatigue can set in as early as day 2 or 3 if you haven’t trained adequately with long back-to-back efforts, but you can’t do anything about that now.)

When it comes to eating and drinking, think before, during, and after. Fuel up every day before you start with a carbohydrate-rich breakfast to maximize your glycogen stores. If you’ll be pushing the pace or racing (working at moderate to high intensity, above 60 percent of VO2max) you’ll need to eat and drink at the earlier end of your acceptable breakfast window to start out on an empty stomach and minimize digestive problems. Drink again as near the start time as you can or top off with an energy gel taken with water. If the day is going to be more of a long, slow effort, then it’s generally OK to eat closer to the start (say, two to three hours beforehand) and to include fattier foods that take longer to empty from your stomach and be digested.

During the event or race, you’ll need to drink regularly (every 15 to 20 minutes) and refuel (every 30 to 60 minutes) from the onset so that you consume at least 30 to 60 grams of carbohydrate per hour. Sports drinks are the rehydrating beverage of choice to replace fluid and electrolytes. Along with sports drinks, a safe approach is to rely on energy gels and well-tolerated carbohydrate snacks during faster-paced efforts. Be prepared with salty foods or electrolyte tablets to help keep pace with your sodium needs. On long, slow days, incorporate real food, especially for the mental boost that it provides.

The key is to drink and snack regularly as you go, keeping pace with the
calories that you’re expending. Unless you have a four-hour or longer break
planned, eating a large amount at any one time, such as a lunchtime meal or a meal during a rest stop, will divert blood away from working muscles when you resume exercising. You will feel lethargic and unresponsive and end the day lamenting how much harder the second half was.

When you’ve stopped moving for the day, your job is not done. You must
consciously take advantage of the carbohydrate window, particularly the first
15 minutes, to maximize the glycogen replenishment process (see chapter 4 for a review). Ingest a substantial amount of carbohydrate calories immediately— at least .5 grams of carbohydrate per pound (~1.0 grams per kilogram) of body weight. (Even better, take in .75 grams per pound.) Remember, these are carbohydrate calories, not just calories from anything, like beer, nacho chips, or a candy bar. A recovery drink or meal replacement beverage can make the job easier (see the chart in chapter 5), and a small amount of protein may help reduce muscle soreness.

Each evening eat a high-carbohydrate meal that includes a good source
of quality protein (for example, 20 to 30 grams as supplied by 3 to 4 ounces,
or 85 to 112 grams, of meat). If need be, eat another carbohydrate-rich snack before bedtime.

Weighing yourself (if feasible) before you begin and right afterward can be
very useful because you can quickly ascertain how well you are doing at meeting your fluid needs during the event or race. Over the next few hours, drink at least 2.5 cups of fluid for every pound (or 1.3 liters for every kilogram) that you are down. If you’re down more than a few pounds, adjust your drinking plan for subsequent efforts and pay attention to your sodium intake too. Losing weight from day to day (especially in events and races lasting longerthan three to five days) and having sore or “dead” legs that are struggling to respond are prime signs of chronic glycogen depletion. Your job is to stop the damage from occurring before it becomes too much to reverse by eating more (especially carbohydrate calories), taking more time to recover, or most likely some of both.”

Optimal Pedaling Cadence

This is an excellent excerpt reprinted with permission from Burke’s book, High-Tech Cycling-2nd Edition.

High-Tech Cycling book cover“Most studies examining pedaling cadence have focused on pedal optimization in terms of economy/efficiency and local muscle stress. In this section, we will summarize the findings of the numerous laboratory studies that have attempted to identify which cadence is optimal. Unfortunately, few investigations have analyzed the question in well-trained cyclists riding their own bikes, making it difficult to apply the findings to actual cycling.

Optimal Cadence and Oxygen Cost: Economy/Efficiency
The two main messages to emerge from the numerous studies published since the beginning of the 20th century are as follows:

  • Low cadences (50 to 60 rpm) tend to be more economical/efficient than high pedaling cadences (> 90 rpm)
  • Paradoxically, most individuals prefer to pedal at high, theoretically inefficient/uneconomical cadences (examples include Boning, Gonen, and Maassen 1984; Cathcart, Richardson, and Campbell 1924; Chavarren and Calbet 1999; Coast, Cox, and Welch 1986; Croissant and Boileau 1984; Gaesser and Brooks 1975; Garry and Wishart 1931; Gueli and Shephard 1976; Jordan and Merrill 1979; MacIntosh, Neptune, and Horton 2000; Marsh and Martin 1997; Marsh and Martin 1998; Seabury, Adams, and Ramey 1977; Takaishi, Yasuda, and Moritani 1994; Takaishi et al. 1996; Takaishi et al. 1998).

A detailed look at the published studies suggests that both general conclusions need to be approached with caution. Several factors may alter the optimal and preferred pedaling cadence, including absolute and/or relative power output (i.e., watts or percentage maximal oxygen uptake [V·O2max], respectively), duration of exercise, test mode (cycle ergometer tests versus riding a bicycle on a treadmill), fitness level of the subject (cyclist or noncyclist), and the high interindividual variability, even among trained cyclists of similar fitness levels, reported by most authors.

In general, during laboratory tests performed by noncyclists at constant power outputs (usually = 200 W), pedaling at low rates (~ 50 to 70 rpm) resulted in lower oxygen uptake (V·O2) than pedaling at higher rates (> 90 rpm). In any case, such a generalization is of little practical value. First, one questions the benefit of optimizing pedaling cadence in subjects whose power output rarely surpasses 200 W, those who cycle for fitness or recreation. Second, elite cyclists are the ones interested in optimizing cadence and making it more economical/efficient, and they are able to generate much higher power outputs during long periods. The average power output of Bjarne Riijs during the 1997 Amstel Gold Race, a World Cup classic lasting over seven hours, was close to 300 W (data from www.srm.de). During the most important stages of professional road cycling races, riders are often required to generate power outputs of over 400 W (Lucia, Hoyos, and Chicharro 2001a), not to mention the one-hour record in a velodrome (Bassett et al. 1999).

Bassett and colleagues (1999) estimated that the mean power outputs required to break the one-hour world records in a velodrome during the last years (53.0 to 56.4 km) ranged between 427 and 460 W. The average power output of Miguel Indurain during his 1994 one-hour record averaged 510 W (Padilla et al. 2000). Probably most pro riders are so economically below 200 W, that pedaling cadence hardly changes anything. Below 200 W, Lance Armstrong’s human engine is probably similar to that of the last rider in the overall classification of the Tour de France in recent years, and pedaling cadence does not have a significant effect on either one. The picture is likely to be different above 400 W, but there are scarce data in the literature related to the oxygen cost of generating power outputs over 400 W for 20 or more minutes (Lucia, Hoyos, and Chicharro 2000), and no data exist on how pedaling cadence could alter this variable. This is the type of information needed in cycling science.

We should therefore be cautious when applying the findings of previous research concerning cadence optimization to highly trained cyclists. The most economical of cadences tends to increase with absolute power output, that is, with watts (Boning, Gonen, and Maassen 1984; Coast and Welch 1985; Hagberg et al. 1981; Seabury, Adams, and Ramey, 1977). For instance, Coast and Welch (1985) showed that the cadence eliciting the lowest V·O2 at 100 and 330 W was 50 and 80 rpm, respectively. Thus, absolute power output is a key factor of cadence optimization and precludes any simple answer to the problem. On the other hand, trained cyclists are more effective than recreational riders at directing pedal forces perpendicular to the crank arm (Faria 1992). Such an ability carries a biomechanical advantage and probably allows trained riders to pedal at high cadences with no major loss of efficiency.

Instead of speaking of an inverse relationship between cadence and economy/efficiency, maybe it would be more correct to speak of a U relationship during constant-load exercise. There may be an optimum pedaling cadence below and above which oxygen cost increases significantly. Yet, can we assign a value to this theoretical optimum cadence at the bottom of the U? Probably not, given the great variability among cadence studies involving trained cyclists yielding the lowest V·O2, from ~ 60 to ~ 90 rpm (Chavarren and Calbet 1999; Coast and Welch 1985; Hagberg et al. 1981).

It is generally accepted that the theoretical optimal cadence in terms of oxygen cost for most humans is generally lower than that preferred by trained cyclists (> 90 rpm). This generalization requires some specification. First, the gap between the most economical or efficient and preferred cadence is usually narrower in trained cyclists. For instance, Hagberg and colleagues (1981) found both to be close to 90 rpm in trained cyclists. Second, few data in the scientific literature concern the preferred cadence of trained cyclists during actual cycling, although it is consistently assumed to be higher than 90 rpm. Indeed, the latter is only really true for one-hour records in the velodrome. Besides, fixed gears are used in velodrome events. Fixed gears are designed so the rider is constantly forced to move the pedals and might elicit different physiological responses than normal, free gears.

Only one report addressed the preferred pedaling cadence of professional cyclists during three-week races (Lucia, Hoyos, and Chicharro 2001b). Among other findings, the mean preferred cadence of the subjects was shown to range from 70 to 90 rpm, and high variability was shown between subjects and the type of terrain (flat versus uphill). High interindividual variability has also been reported for the preferred cadence of trained cyclists (72 to 102 rpm) during laboratory testing (Hagberg et al. 1981).

Finally, irrespective of the cadence adopted, the oxygen cost of pedaling is largely determined by the percentage distribution of efficient type I fibers in the main muscles involved in cycling—the knee extensor muscles, particularly the vastus lateralis—at least in trained cyclists (Coyle et al. 1991, 1992). We could speculate that, in subjects with a particularly high percentage distribution of type I fibers in the knee extensor muscles, the choice of theoretically inefficient/uneconomical cadences (too low or too high) would have a lower impact on the metabolic cost of cycling than would that choice in cyclists with a smaller proportion of this fiber type.”