VO2 max and Cyclists: Important or Irrelevant

June 16, 2010

VO2 max is one of the most commonly measured physiological variables. Endurance athletes spend countless hours discussing, comparing and worrying about their VO2 max scores. Cyclists are always quoting VO2 max scores for one top rider or another. Is all the attention that this physiological variable gets really worth all the effort?

VO2 max is the maximum amount of oxygen that your body can take in and use. It is a function of both the body’s ability to deliver oxygen via the heart, lung and blood and the body’s ability to use oxygen in the working muscles and other tissues.  While there are some exceptions, Elite cyclists typically have VO2 max scores in the 70-75 ml/kg/min range, similar to that seen in well trained amateur cyclists and some very fit age group riders. In an aerobic sport oxygen consumption is tightly tied to energy expenditure and generally producing more energy means more power and work. The relationship between power and oxygen consumption is not perfect; efficiency or economy play an important role in determining how strong the relationship is in each person.

Gross efficiency, the ratio of power output to power input, is a key determinant of cycling performance (1).  A higher efficiency allows a cyclist to work at lower percentages of the VO2 max to accomplish the same or more work as a less efficient cyclist. In fact, a high efficiency rating can make up for lower VO2 max scores. Alejandro Lucia and coworkers (2) from the Universidad Europea de Madrid examined the relationship between VO2 max and cycling efficiency and gross efficiency in a group of elite cyclists. The subjects in this study were all world class riders having won at least one major professional race, defined as stage in the Tour de France, Giro d’Italia or the Vuelta a Espana, or finished in the top three at the World Championships. Hemoglobin and hematocrit levels were measured prior to the start of the study to ensure they were within normal physiological ranges.  All subjects performed a VO2 max test following standard protocols.  Later the same day they performed a 20 minute constant load test where they road at 80% of their VO2 max. VO2 max values in the subjects varied from a high of 82.5 ml/kg/min to a low of 65.5 ml/kg/min. Cycling efficiency varied from 97.9 watts/L O2/min to 72.1 watts/L O2/min. There was a significant inverse correlation between VO2 max and cycling efficiency. This means that those with the higher VO2 max scores had the lowest efficiencies and those with lower VO2 max scores had higher efficiency. A similar pattern was seen in gross efficiency. Power to weight ratio at VO2 max was not significantly different between riders, they were all in the 4.9-5.4 W/kg range. Interestingly two of the most accomplished riders, a road race and time trial world champion and climbing specialist who had won five stages in the Tour de France both had VO2 max score under 70 ml/kg/min.

This study clearly shows that VO2 max is less important than efficiency in cycling performance and that a high level of efficiency can make up for a lower VO2 max. This pattern is not unique to cycling it has also been seen in running (3) and rowing. In an upcoming article we will look at the various factors that contribute to efficiency and how to improve your cycling efficiency.

So the next time someone start bragging about their VO2 max score ask them about their efficiency rating. Their high VO2 max may just mean that they are very inefficient riders.

  1. Coyle, E. (1995). Integration of the physiological factors determining endurance performance ability. Exerc Sport Sci rev. 23: 25-64.
  2. Lucia, A.  et al. (2002). Inverse relationship between VO2 max and economy/efficiency in world class cyclists. Med Sci Sports Exerc. 34: 2079-2084.
  3. Saltin et al. (1995). Morphology, enzyme activities, and buffer capacity of Kenyan and Scandinavian runners. Scand J. Med Sci Sports. 5: 222-230.
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Squatting Improves Speed

June 10, 2010

Modern strength training programs for athletes spend an inordinate amount of time focusing on using unstable surfaces, single leg exercises and balance training to improve speed, strength and power.  There is currently no research that shows that these types of training improves athletic performance (1) but it has been well established that training on unstable training results in significantly less force development and loads that will limit strength gains (2). All this balance and stability training has come at the cost of building strength in traditional exercises like the squat, bench press, deadlift, and power clean yet these exercise have time and again been shown to be key to athletic performance. A recent study at Applalachian State University examined the relationship between squat strength and sprint speed(3).  The subjects were a group of 17 football players with an average height of 1.78m and an average weight of 85.9 kg.  1RM squat was assessed on the first day of the study. All subjects were required to squat to a 70o knee angle, making it a deeper squat than the 90o knee angle that many people use in training. A deeper squat will normally decrease the amount of weight lifted. The average 1RM squat was 166.5 kg. Later in the week the subjects performed electronically timed 5, 10, and 40m sprints on a standard outdoor track surface. When they analyzed the data they found significant correlations between squat strength to body weight ratio and the 10m and 40m sprints.  When the group was divided into those with a squat to bodyweight ratio of greater than 2.1 and those with a ratio of less than 1.9 those with the higher strength to weight ratio were significantly faster than those with a squat to bodyweight ratio less than 1.9. This study adds to the growing body of evidence that shows the importance of traditional strength training exercises for improving athletic performance.

So why does improved strength improve speed and acceleration? Think back to your high school physics class and you might remember the formula F=ma; force is equal to mass times acceleration.  Transforming the formula to solve for acceleration we get a=F/m; acceleration is equal to force divided by mass. When we are speaking of running or jumping activities the mass is your body weight. If you increase your strength to body weight ratio you will increase your speed and acceleration; it is simple physics.

Unstable surface, single leg and balance training may be fine during a warm up but they are no replacement for good old fashioned deep squats when it comes to increasing strength and improving speed and power that translates to athletic ability. So if you want to get faster stop using circus tricks and lift some real weights.

  1. Wilardson, J. (2004). The effectiveness of resistance exercise performed on unstable equipment. JSCR. 26(5) 70-74.
  2. Behm et al (2002). Muscle force and activation under stable and unstable conditions. JSCR 16(3) 416-422
  3. McBride et al (2009). Relationship between maximal squat strength and five, ten, and forty yard sprint times. JSCR. 23(6) 1633-1636.

Slushies Improve Performance

June 8, 2010

Heat is a major limiting factor in endurance performances.  It has been quite well established that as temperature increases so does marathon time. Over the past 5-10 years more and more attention has been paid to dealing with heat stress while training and competing. Ice vests have proven to be quite effective when worn for a period of time immediately prior to a race but are often impractical and quite expensive. There is evidence that consuming cold water can improve time to exhaustion and running performance compared to warm water (1). Recently this idea was taken a step further by a group of Australian researchers. Using a group of ten moderately trained recreational runners, they examined the effects of drinking a Slushie right before running compared to cold water. All subjects participated randomly in both trials, running as long as possible at their aerobic threshold in a warm environment of 34oC and 55% humidity. Before each run the subjects ingested 7.5g/kg of either a Slushie or the cold water. The temperature of the Slushie was -1oC and the cold water was 4oC. Both drinks contained a 5% carbohydrate solution. When the subjects consumed the Slushie they ran 19% longer than after consuming water. Both groups were equally hydrated at the start of their runs but the Slushie group had a lower rectal temperature. Interstingly the Slushie group maintained a lower body temperature for the first 30 minutes of their run but ended up with a higher temperature at exhaustion. The authors have suggested that the colder temperature of the Slushie may have decreased brain temperature and delayed the point where a critically high brain temperature causes fatigue, around 42oC.  This study clearly shows that Slushies are performance enhancers when you are exercising in the heat. So next time you head off for a training session run by 7-11 or Mac’s Milk for a quick slushie, it will make those training sessions in the heat more tolerable and even improve your performance.

Lee JK, Shirreffs SM, Maughan RJ. Cold drink ingestion improves exercise endurance capacity in the heat. Med Sci Sports Exerc. 2008;40(9):1637–44

SIEGEL, R., J. MATE´ , M. B. BREARLEY, G. WATSON, K. NOSAKA, and P. B. LAURSEN. Ice Slurry Ingestion Increases Core Temperature Capacity and Running Time in the Heat. Med. Sci. Sports Exerc., Vol. 42, No. 4, pp. 717–725, 2010.


Beta Alanine – A Cyclists Best Friend

March 18, 2009

Ed McNeely

 Cycling, particularly road racing, crits, and time trials are endurance sports where the training focus is long distance training. Despite the endurance requirements many races come down to a final sprint that is dependant on very short term peak power. Strength training and cycling specific sprint training can improve this ability but the fastest way to bump up your short term power may be a nutritional supplement called Beta Alanine.

 Beta alanine is an amino acid the is converted to carnosine in the body. Carnosine is an intramuscular buffer which accounts for about 10% of a muscle’s buffering capacity. During intense exercise there is a build up of H+ from lactic acid and other sources which can negatively affect muscle contraction and contribute to fatigue. Increasing carnosine concentration in the muscle can delay fatigue caused by H+.

 A recent study published in the American College of Sports Medicine Journal (Med Sci Sports. Vol 41 pp 898-903) examined the effects of beta alanine supplementation on sprint ability at the end of a 110 min cycling performance. The subjects were 21 male recreationally competitive cyclists divided into a placebo and Beta Alanine group in a double blind fashion so that neither the researchers or the participants knew who was in which group. The Beta Alanine group used 2g per day for the first 2 weeks, 3g per day for the next two weeks and 4g per day from week 5 to the end of the eight- week study. Both groups kept to their normal training routines throughout the study.

 Before and after the supplementation was started all subjects completed a simulated 110min time trial immediately followed by a 30s all out sprint. Following the treatment the Beta Alanine group improved their average power over the 30s by 5%; there was no change for the placebo group. Peak power, during the sprint, improved by 11.4% for the beta Alanine group with no change for the placebo group. Interestingly, all of the subjects in the Beta Alanine group saw improvement in both Peak and mean power while many of the placebo group decreased both peak and mean power during the sprint.

 Beta alanine has been around for a few years and the research clearly supports it’s use for improving short- term sprint performance in both endurance and speed and power sports. There have been no reported side effects of Beat alanine supplementation.


Creatine and Rowing

January 26, 2009

Ed McNeely

It is often difficult for coaches and athletes to keep up on the latest training innovations and findings. The purpose of this column is to review and comment on research that is currently being done on rowing and training for endurance sports. I will try to make a link between the research and practical application for the rower.

Reviewed Study

Effect of Creatine Monohydrate Supplementation During Combined Strength and High Intensity Rowing Training on Performance. Syrotuik, D., Game, A., Gillies, E, and Bell, G. Canadian Journal of Applied Physiology. Volume 26(6): pages 527-542.

Creatine supplements are among the most popular nutritional supplements on the market. It has been marketed as a means of increasing endurance, recovery, strength, muscle mass and decreasing body fat. Over the past 5 years there has been substantial research on the effects of creatine supplementation on training and performance. Most studies show an increase in endurance during short sprint events. Strength increases seem to be greater in athletes using creatine; unless they follow a periodized strength program then there is little difference between creatine groups and placebo groups. While there is growing evidence that creatine supplements can aid training there are very few studies that have been able to show a link between creatine supplementation and improved performance.

Creatine increases the energy producing capacity of the anaerobic alactic energy system. Making it an ideal supplement for short duration very high intensity efforts that rely primarily on this energy system. Creatine supplements have been thought to be of limited benefit to athletes whose event lasts more than 3 minutes, which rely heavily on the aerobic system. Several years ago a study examined the effects of acute creatine supplementation on 1000m ergometer performance and found improvements in the split time over the first 500m, which translated into a faster 1000m race time. A more recent study has looked at the effects of 6 weeks of creatine supplementation on 2000m ergometer performance.

Twenty-two college rowers (12 male, 10 female) volunteered for the study. There were randomly assigned to either a creatine supplement group or a placebo group. All subjects were tested 3 times for the following variables; body composition, VO2 max, 2000m erg performance, 6 x 250m sprint, and strength tests for the leg press and bench press. Tests were conducted prior to training, after a creatine load week and 5 weeks later at the end of the study.

The study was divided into 3 phases; a three week pre-experimental phase where the subjects rowed three steady state sessions and one 4 x 500m session per week. They performed strength workouts twice per week. The second, creatine load, phase was one week long consisting of one strength session and two 5000m rows. The final phase of the program involved two rows at anaerobic threshold, one session of 250m hard: 250m easy one session of 500m hard:500m easy, and 2 strength training sessions. The strength training program consisted of a periodized resistance program, which consisted of 5 upper body and 4 lower body exercises.

Using a double blind protocol the creatine supplement group received 0.3g/kg of creatine, dissolved in 1L of flavored drink during the loading phase and 0.03g/kg dissolved in 250 ml of flavored drink during the training phase. The placebo group consumed only the flavored drink.

Both groups increased lean body mass, decreased fat percentage, improved 2000m rowing performance, increased strength and improved performance in the 6 x 250 m test. There was no difference between the two groups for any of the variables measured.

The results of this study are quite interesting. The other two studies that have looked at creatine use and rowing performance have both shown performance improvements over a 1000m or 2500m race. The majority of improvement occurred during the first 500m of the test in those studies. This would be expected for a 1000m race, where a larger proportion of the energy used in the race will come from the anaerobic energy systems.

One way of explaining the differences in these studies is the tactics used during the erg test. Using a creatine supplement may allow you to go out a little harder during the first 500m. Since the subjects in the current study did not know if they were taking the creatine supplement or the placebo they may not have adjusted their race plan to account for the increased capacity of the anaerobic alactic system during the first 500m.

Supplementation can be expensive. Whether it is creatine or another supplement it is important to set up a controlled testing scenario to determine if the supplement you are taking is having any effect on your performance. You will need to have a very good understanding of what the supplement is supposed to be doing and the physiology of rowing to do this, but it may save you a lot of money in the long run.

While there are some problems with this study, the training volume is lower than a collegiate rower would typically use and some of the subjects were relatively inexperienced, the lack of difference between the two groups should make us stop and think before we decide to use a creatine supplement to improve rowing performance.


Tapering for the Big Event

January 17, 2009

Ed McNeely

During the final preparation for a major competition, the athlete needs to feel rested, quick, and strong. To accomplish this, a taper is often used. A taper is a period of drastically reduced training volume that lasts from seven to 21 days prior to the year’s major competition (Costill et al., 1985; Houmard and Johns, 1994).  The objective of training is to induce physiological and mechanical changes in an athlete so that their performance improves. During periods of high-volume training common to rowers training adaptations are often masked by the fatigue of incomplete recovery between sessions (Zatsiorsky, 1995)(figure 1). The main purpose of a taper is to allow the physiological systems to completely recover and adapt. In order to plan a taper training volume, intensity, frequency, and duration all need to be considered.

 Volume

 In studies of distance runners, (Houmard et al., 1990, 1991) found that 800m and 1600m running times were improved following a decrease in training volume of 70% over a three-week period. Houmard (1994) found an increase in running economy and a 3% improvement in 5km run time following a seven-day 85% decrease in training volume. If training volume is not sufficiently reduced there appears to be no improvement in performance. Sheply et al. (1992) looked at the effects of a seven-day 62% reduction in volume and compared it to a seven-day 90% reduction in volume. They found the 62% scenario did not increase the time to exhaustion. On the other hand the 90% reduction resulted in an 22% increase in time to exhaustion. A 40-day taper in which training volume was reduced by 76% resulted in a 2.8% increase in swim performance (Johns et al. 1992). Mujika et al. (1995) found there is a significant relationship between the amount of volume decrease and performance improvements during a taper. From the available data, it appears that reductions in training volume of 70 to 90% are necessary for a taper to be most effective.

 A taper can either be progressive, meaning there is a gradual decrease in volume over the period of the taper, or it can be stepped, meaning there is a single decrease in volume for the duration of the taper (Mujika, 1998). Martin et al. (1994) found that performance improvements peaked during the first week of a two-week step taper in cyclists. Zarkadas et al. (1994) found an 11.8% improvement in 5km run times following a 10-day progressive taper but only a 3% improvement in performance using a step taper. Houmard et al. (1990) found no improvement in performance following a three-week step taper. Progressive tapers seem to have a greater impact on performance than step tapers (Mujika, 1998). This is probably due to detraining effects that occur when the rapid volume decrease used in step tapering is maintained for an extended period of time. While a progressive taper is the obvious choice for the major competition of the year, a step taper may be better for qualifying competitions and other less important events where the taper duration is much shorter.

Frequency

Training frequency refers to the number of training sessions per week. The reduction of training volume in a taper should not occur as the result of drastic changes in training frequency (Houmard and Johns, 1994). Neufer et al (1987) found that reducing training volume (80 to 90%) through cutting frequency by 50 to 85% resulted in decreased swim power after only seven days of tapering. Studies in which tapering has resulted in improved performance have typically decreased frequency by 20 to 50%. Houmard et al. (1989) has recommended that training frequency not be reduced by more than 20%. The reasons why a reduction in frequency causes a decrease in performance is unclear, but may be related to decreased technical efficiency. As frequency of technical work is decreased there is probably some loss in technique that ultimately affects performance.

 Intensity

Intensity during a taper is usually maintained or increased. There is a tendency for a greater proportion of the training to become race- specific type intervals. In rowing, this translates into increased training in categories III and II. The time period between the intervals should be long enough to maximize intensity. Hickson et al. (1985) reduced training intensity by 66% and found that cycling time to exhaustion decreased by 21%. In a study that compared high intensity and low intensity tapers Shepley et al. (1992) found that the physiological responses to the two tapers were similar but only the high intensity taper group showed an increase in performance. Houmard and Johns (1994) suggested that training schedules that use intensities of less than 70% VO2 max maintain, or decrease performance during a taper, while schedules which use intensities of greater than 90% VO2 max improve performance. The higher intensity training allows athletes to get used to higher stroke rates, allows them to work on race strategy and tactics, and psychologically give them feelings of speed and power.

Duration

Since the training stimulus is greatly reduced during a taper, the duration of the taper can have an impact on the magnitude of performance improvements. Within one to four weeks of stopping training highly trained athletes start to show decreases in performance (Costill et al. 1985). Mujika et al. (1996) studied the effects of 21-, 28- and 42-day tapers on performance in highly trained swimmers. They found significant improvements in the 21- and 28-day groups but not the 42-day taper group. Several studies have looked at physiological changes associated with tapering and found that haemoglobin and hematocrit peaked after seven days of taper (Yamamoto et al. 1988).  Studies that have measured performance and taper duration have found improvements in performance following tapers of seven to 21 days (Costill et al. 1985; Houmard et al, 1994; Sheply et al. 1992).

 The number of days needed to taper may be affected by training volume and intensity going into the taper and fitness level of the athlete. Mathematical models have been developed to try and predict the optimal number of days needed to taper (Mujika et al., 1996; Fitz-Clarke et al., 1991; Morton et al., 1991). The models have suggested that tapers should not be longer than 16 days. However, there have been discrepancies between the mathematical models and measured performance peaks. More time is needed to validate these models before they can be used with complete confidence. As a general rule the taper duration should be a function of the competitive level of the athlete. Lower level athletes can get away with a sevenday taper while national level athletes need a 14- to 21-day taper.

Special Considerations During a Taper

The taper period can be a time of high psychological stress for both the coach and athlete. Coaches tend to worry about the training that was done during the season, the duration of the taper, and many other things that arise prior to a major competition. It is important at this time of the year that the coach projects confidence both in what has been done during the season and in the taper. If the coach is openly worried about the athlete’s preparation or starts making  changes to a planned taper the athletes may begin to question their preparedness and ability to win.

 Athletes handle the decreased training volume differently. Many athletes will enjoy the feelings of speed, power and renewed energy. Others have a tough time dealing with the decrease in volume. They worry about detraining and don’t know how to cope with the extra time as a result of the decreased volume. A coach needs to be aware of the responses of each athlete, and be prepared to deal with the worriers.

 Some athletes need to pay attention to their weight during a taper. One of the adaptations to a taper is an increase in muscle glycogen storage (Sheply et al. 1992). For every gram of glycogen stored in the muscle three grams of water are stored. This can result in a large increase in weight in a relatively short period of time. A certain amount of weight gain may be necessary if the athlete is to see performance improvements as a result of the taper. The increased glycogen storage not only feeds the muscles during training but it is used as an energy source for other adaptations to occur. These atheltes have to carefully balance the amount of glycogen supercompensation that will improve performance with the amount of weight they can gain.

 Conclusion

A well-designed taper can improve performance by about 3% over the year’s best performance. The taper should involve a progressive decrease in training volume of 70 to 90% and an increase or maintenance of training intensity over a seven- to 21-day period. The decreased training volume should be accomplished by decreasing distance or time per session. The number of training sessions per week should not be reduced by more than 20 to 50%.

 

References

Costill, D., et al. (1985). Metabolic characteristics of skeletal muscle during detraining from competitive swimming. Med. Sci. Sports Exerc. 17: 339-343.

 Fitz-Clarke, J., et al. (1991). Optimizing athletic performance by influence curves. J. Appl. Physiol. 71: 1151-1158.

 Hickson, R., et al. (1985). Reduced training intensities and loss of aerobic power, endurance, and cardiac growth. J. Appl. Physiol. 58: 492-499.

 Houmard, J., et al. (1989). effects of reduced training on submaximal and maximal running responses. Int. J. Sports Med. 10: 30-33.

 Houmard, J., et al. (1990) Reduced training maintains performance performance in distance runners. Int. J. Sports Med. 11: 46-52.

 Houmard, J., et al. (1994). The effects of taper on performance in distance runners. Med. Sci. Sports. Exerc. 26: 624-631.

 Houmard, J. (1991). Impact of reduced training on performance in endurance athletes. Sports Med. 12: 380-393.

 Houmard, J. and Johns, R. (1994). effects of taper on swim performance: Practical implications. Sports Med. 17: 224-232.

 Johns, R., et al. (1992). Effects of taper on swim power, stroke distance and performance. Med. Sci. Sports Exerc. 24: 1141-1146.

 Martin, D., et al. (1994). Effect of interval training and taper on cycling performance and isokinetic leg strength. Int. J. Sports Med. 15: 485-491.

 Morton, R., Fitz-Clarke, J., and Banister, E. (1990). Modelling human performance in running. J. Appl. Physiol. 69: 1171-1177.

 Mujika, I. (1998). The influence of training characteristics and tapering on the adaptation in highly trained individuals. Int. J. Sports. Med. 19: 439-446.

 Mujika, I., et al. (1996) Modelled response to training and taper in competitive swimmers. Med. Sci. Sports Exerc. 28: 251-258.

 Mujika, I. et al. (1995). Effects of training on performance in competitive swimmers. Can. J. Appl. Physiol. 20: 395-406.

 Sheply, B., et al. (1992). Physiological effects of tapering in highly trained athletes. J. Appl. Physiol. 72: 706-711.

 Yamamoto, Y. et al (1988). Hematological and biochemical indices during the taper period of competitive swimmers. In Ungerects et al (Eds) Swimming Science V, International series on sports sciences. 18: 243-249. Human Kinetics Books, Champaign Ill.

 Zarkadas, P., Carter, J., and Banister, E. (1994). Taper increases performance and aerobic power in triathletes. Med. Sci. Sports Exerc. 26: 34

 Zatsiorsky, V. (1995). Science and Practice of Strength Training. Human Kinetics. Champaign Ill.


Age and gender responses to strength training and detraining

January 16, 2009

By Ed McNeely

Age may be a more important factor in strength gains than gender.  A recent study examined the effects of nine weeks of strength training on groups of young and older men and women. It was found that both men and women gained strength at a similar rate.  However, the younger participants, average age 25.5 years, increased their strength by 34% while the older participants, average age 68.5 years, increased their strength by 28%. The older participants also lost strength more quickly than the younger group. Following 31 weeks of detraining the younger group had lost only 8% of the strength they had gained while the older group had lost 14%.  This data reinforces the importance of consistent physical activity for seniors.

 

Lemmer, J., Hurlbut, D., Martel, G., Tracy, B., Ivey, F. Metter, E., Fozard, J., Fleg, J., and Hurley, B.  Age and gender responses to strength training and detraining. Med. Sci. Sports. Exerc. 32: pp1502-1512.  2000