Yes it does! Numerous studies have confirmed the efficacy of Carbohydrate loading in increasing performance during endurance exercise. Muscle and liver glycogen depletion leads to fatigue in long term endurance exercise. As a result, making sure that those reserves are at their very fullest is paramount to ensuring your best possible race day. A common approach is that during the last 7 days prior to competition the athlete will combine a high carbohydrate diet with tapering of training. The diet should provide adequate calories and carbohydrate per day: 8-10 grams of carbohydrate per kilogram of body-weight per day. This should increase glycogen stores 20% to 40% above normal. Even higher amounts, 10-12 grams per kilogram of body weight, have been suggested for ultra endurance events. This is not to be seen as Carte Blanche to overeat to excess. It is recommended to maintain caloric intake steady or increase slightly but increase the percentage of calories from carbohydrate to 65%-75% during the "loading and supplementation" phase. One caveat in the research relates to women. Carbohydrate loading has been proven effective in men on multiple studies, but the results for women have been less consistent. One theory as to why that is relates to the overall caloric consumption by the women in the studies. It has been postulated that women just were not taking in enough calories to stimulate the glycogen storage super-compensation seen in men. It would seem that women who ingest less than 2,400 KCals per day find it difficult to consume sufficient amounts of carbohydrate. Therefore, athletes may need to increase their total daily energy intake above 2,400 KCals, in addition to increasing their carbohydrate intake, in order to increase their glycogen stores. This conclusion was substantiated in a study in which subject were randomly assigned to one of three diets: high carbohydrate (75% of KCals), high carbohydrate plus extra calories (75% of KCals from carbs and 34% increase in overall KCals) or their habitual diet. For the women ONLY the High Carbohydrate PLUS Extra calories saw significant increases in glycogen storage.
So, if you're in your last week before your endurance event, enjoy some extra carbs!
YES, YOU DO!! As endurance athletes we are often prone to the "more is better" approach to training. While overreaching for limited periods to stimulate positive adaptations is the basis, and indeed a necessary part, of a good training program, it is important to balance it with recovery to allow for those adaptations to occur. Continuing to overreach beyond the functional and into the non functional can lead to over-training, a potentially very dangerous and debilitating state of physical, endocrine and mental exhaustion. Remember, you DO NOT become more fit while training. Exercise creates only the potential for fitness. It is during the rest & recovery period following hard training that fitness actually happens. How do you know when you're pushing too hard? Unfortunately there is no absolute metric or sign that can, with absolute certainty, tell you you're exceeding your current limits. What there is, however, is a multitude of "weak indicators" that will paint a progressively more compelling picture alerting you that you are flirting with trouble if you do not take action. These are called "weak" because each one in isolation is not sufficient to provide strong evidence. It may very well be that, at times, you may get one of these isolated red flags even when things are going well. It is the combined weight of several indicators that will tell you it's time to pull back. What are these "indicators"?
Some of the most common ones are listed below with the warning signs following. These are when you wake up in the morning and are indicators of stress your body is struggling to cope with.
Sleep - Poor quality and/or inadequate duration
Overall Feeling - Very fatigued & Stressed
Mood - Unusually grumpy
Appetite - Diminished
Motivation to train - Low
Muscles, Joints - Sore
Waking Pulse - Elevated
Heart Rate Variability - Low
I recommend selecting a few that are the most easily monitored daily. Experiment with them. Over time you will find which ones work best at predicting your state of fatigue.
Running is hard work, we can all agree. All athletes try to minimize the amount of work performed to sustain a given speed. In other words, we are all trying to be as economical as we can. That is a good thing since, unlike VO2 max, running economy is a very strong predictor of distance running performance. Running economy is the oxygen cost of running at a given speed. Thus, an athlete with good economy will run a certain pace at a lower percentage of VO2 max than one with poor economy. The percentage of VO2 max associated with a pace has a strong effect on how long that pace can be maintained. It logically follows that the more economical a runner you are, the faster you can run for longer, which is the very definition of better performance. It therefore clearly makes sense to devote a significant amount of effort to becoming a more economical runner, rather than just a fitter runner, since just being fit will not necessarily make you faster. But what workouts affect economy the most? Running form improvement, strength training, explosive drills and hills have all been shown to improve running economy. Increased mileage, a staple in classic training philosophy however, is a very weak stimulus for improved economy, especially at race speeds. In targeted studies increased volume failed to improve economy while the introduction of explosive training did in every instance. Furthermore, the pursuit of economy should be ongoing year-round rather than confined to a few weeks at a time. It seems clear that quality in your training trumps volume. Improve your Economy, and reap the benefits in your next race!
Speed Work. As an athlete, you either relish it or despise it. As an endurance athlete, you might even have decided it is not a necessary part of your training. To these athletes I say “Add speed to your routine now!” The question is not whether you SHOULD do speed work, but rather how fast should it be? Although counter-intuitive, there is a high correlation between the maximal speed of a runner, such as 50-meter sprint time, and performance in an endurance event, such as a 10K or longer race. This relationship is far stronger than that between VO2 max and endurance distance performance. Why you ask? It turns out that performance is far more complex than simply the size of one’s aerobic engine. Neurological coordination of the musculoskeletal system is a key factor in fast running. Most importantly, the nervous system’s role in speed development is totally independent of the energy producing systems inside the muscles. Fortunately for athletes, this coordination needs to be developed over time and can be trained. The type of training required for this development is different than what most athletes might consider speed work. We are talking about specific true max speed workouts designed to improve stride rate and stride lengths to optimize speed. Yes, these are characteristics that can be altered through training in relatively short amounts of time, and they can have a huge impact on your race times. Bear with me as we dive into a practical example that I think will be enlightening. A 3:30 marathoner with a stride rate of 90 will take 37,800 steps in her marathon. Let’s assume her GCT (Ground Contact Time or time spent on the ground during each stride) is an average 230 milliseconds. If she can reduce her GCT by 5% (or 12 milliseconds), and nothing else, her marathon time would drop by 435 seconds, or 7 minutes and 15 seconds. Who amongst you wouldn’t take that? Reach out for more info.
If you’re a runner or triathlete it is very likely you either know your VO2 max value or know about VO2 max. Often, athletes focus on their VO2 and assume that higher means faster, but raw VO2 max is not a great predictor of endurance performance.
All else being equal, having the capacity to utilize more oxygen per unit of time should make you aerobically more powerful. However, what athletes often overlook is the impact of running economy. An athlete with a higher VO2 max value is not necessarily guaranteed to win against someone with a lower value.
This is where economy comes into play. VO2 max is similar to car engine size, but we all know that a bigger engine is not always synonymous with faster speed. It’s the extent to which you utilize that displacement that determines power and speed in a car. Similarly, efficient running will be a determining factor of your sustainable speed.
So why focus on your raw VO2 max value? What if we could use a metric that also incorporates running economy? That’s where vVO2 max, or velocity at VO2 max, comes in. This is the minimum speed required to induce a runner’s maximal rate of oxygen consumption, or VO2 max. Unlike VO2 max, vVO2 max is a strong predictor of endurance performance.
Although exact measurement requires lab testing, the cost can be high and regular testing is out of reach for most age group athletes. It is however possible to achieve fairly accurate and repeatable results with field testing, which costs nothing and can be performed regularly to update your training parameters. Any successful training program has to start with accurate individualized information. This data will allow a coach to tailor the program to the goals, strengths and weaknesses of the athlete. As the athlete progresses, this data must be updated to allow for further progress and adaptation. Make sure you focus on the important variables to ensure success!
Like VO2 max, most athletes are aware of Threshold and its importance in endurance performance. But do you know what your threshold is and how it relates to the other big name in Endurance Performance metrics – VO2 max? Threshold is defined in numerous ways, depending on where physiologically you are starting your thought process. At its base, it is the intensity at which lactate, and accompanying fatigue, starts accumulating in your bloodstream. Functionally, the intensity you can maintain in a steady state for approximately one hour is the practical definition we will work with. Threshold is also closely related to VO2 max. It is useful to define it as the Fractional Utilization of maximal oxygen uptake, or % of VO2 max. For untrained individuals, it can be around 50% and for highly trained athletes it can be as high as 90% and the ceiling is largely genetically fixed. It should be noted that the percentage will be different for the same athlete for different sports, so sport specificity is critical. Athletes tirelessly work towards increasing their Threshold, as it possibly is the best predictor of endurance performance, but often forget about its relationship with VO2 max. As a result, they become frustrated when gains start slowing or stop altogether. Remember the fractional utilization aspect of threshold? If you increase VO2 max, your threshold will rise as well. All too often endurance athletes shun speed or high intensity work with the belief it does not benefit them. Doing so stagnates VO2 max, and with it so does Threshold development once maximal fractional utilization is achieved. I always track at what % of VO2 max my athletes achieve Threshold, with Heart Rate, Power and Pace to make sure that when they hit that ceiling, we shift training focus to Aerobic Capacity to allow for further threshold improvement. It is the hallmark of a good training program to be adaptive to the athlete’s response to previous training to ensure proper training stimulus is applied at the right time to maximize performance gains.
Fatigue Resistance. We’ve all heard of it. We all train hard to achieve it. But what are the best ways to do that? What should our focus be? Cardiovascular? Musculoskeletal? Neural? The answer is all three although most athletes will focus only on the first two. Having fully developed cardiovascular and musculoskeletal systems is critical. However, many athletes with superior physiological attributes and high levels of fitness will underperform compared to their potential due to fatigue that has nothing to do with their bodies’ ability to perform. Rather, it’s their “neural governor” holding them back. Yes, fatigue is to a significant extent a mental construct that has little relation to what is happening with the heart and muscles! Have you ever experienced a workout where your last hard effort feels easier and is faster than your previous ones? You are arguably at your most tired, glycogen depleted and fatigued state, but yet your performance has improved. There doesn’t seem to be any other reasonable or scientifically substantiated explanation except for the effect to be mental. Your brain is protecting you from yourself! So, now what? Don’t despair, a number of studies have provided evidence for the trainability of the neural governor. Although still developing and not as thoroughly investigated as other aspects of training such as VO2 max, it is known that high intensity, explosive strength training upgrades neural output. A well-structured training plan, with the inclusion of workouts involving high levels of neural drive, should lead to improvements in fatigue resistance and ultimately better race day performance. Let me know if you’d like more detail
Do you know the Aerodynamic Cost of your Water Bottles?
We are all aware of our need to replenish our fluids and fuel during training and racing, but are we really aware about how important it really is? Fact is that fatigue toward the end of a prolonged sporting event may result as much from dehydration as from fuel substrate depletion. Exercise performance is impaired when an individual is dehydrated by as little as 2% of body weight. Losses in excess of 5% of body weight can decrease the capacity for work by about 30% (Armstrong et al. 1985; Craig and Cummings 1966; Maughan 1991; Sawka and Pandolf 1990). The question now is, "How much fuel and hydration can I carry during a long course race (Half and Full Ironman)?" The next question you should ask yourself is “How can I minimize the aerodynamic cost of carrying these items?”. We all strive to be as efficient as we possibly can. After all, why do more work than necessary, right? Bike fits, aero bike frames and helmets, deep or disc wheels and speed suits all improve our aerodynamics, although at a hefty financial cost. Did you know that water bottle selection and positioning can negate a great percentage of the advantages you paid so much for? Aerodynamics is all about airflow management. The goal is to allow air to flow around our bodies and bikes as smoothly as possible and that means minimize obstructions that cause turbulence and increase drag. You want to present the smallest profile to the wind as well as the smoothest path for air to flow over. That is achieved by a combination of a good body position and strategic selection and placement of bottles. Front mounted systems tend to be the most aerodynamic, but have capacity limitations and can make your bike harder to handle. Frame mounted bottles are the next best thing, but bottle selection and placement have a significant impact. Finally, rear mounted systems are aerodynamically the costliest but also the ones with the most capacity and the ones triathletes tend to default to. Here the goal is to tuck the bottles below the saddle and minimize the gap between the saddle (your bottom) and the bottles to reduce the turbulence as much as possible.
The attached image shows air flow around a typical triathlete. Notice the blue zones of disturbed airflow and the red ones where air flow is severely disturbed. The area behind the saddle is of particular importance as this is where most athletes chose to place their bottles and often do so in a non-optimized way. The net result is the extension of the disturbed area well to the rear, greatly increasing aerodynamic drag.
Even in an Ironman race you don’t have to carry all your fluids. Some research into what is offered at the aid stations and how far they are apart will allow you to minimize what you need to carry. Combined with strategic bottle selection and positioning, you can enjoy a faster bike split.