With Barry Publow

Question:

I recently competed in a half-marathon event and after about 10K, I was totally exhausted. After losing contact with the group I was in, I wound up skating with another group that caught me from behind. In the final 5K of the race I began to feel great. In the end, I felt strong and had a good finishing sprint. My question is what sort of training should I do to help me start out faster without bonking?

Answer:

To the best of my knowledge, the term “bonking” was first coined by marathon runners, and was used to describe the sudden onset of fatigue that inevitably struck during the latter stages of a race – usually around the 18-20 mile mark. This bonking occurs as a direct result of fuel depletion. That is, the body simply runs out of glycogen stores – an energy-rich fuel stored in the liver and within the muscles themselves. The actual rate of glycogen used is directly proportional to the duration and intensity of effort. The higher the intensity, the faster the rate of glycogen usage. Within limits, it’s an issue of supply and demand.

When fully stocked, the body can sustain energy-yielding, glycogen-based processes for approximately 2 hours. Once the glycogen is depleted, the body must rely almost exclusively on fat and protein metabolism for energy. While fat molecules are a functional source of energy, the slow rate at which fats can be transformed into useable energy means that high intensity physical effort cannot be sustained with this fuel source alone. The only way to sustain prolonged exercise (generally, in excess of 2 hours) is to ensure that some sort of carbohydrate source (energy bar or gel) is consumed during the course of the activity.

Often, the term “bonking” is used to describe an entirely different thing. The end result (fatigue) may be the same, but the mechanism for inducing fatigue can be very different. For long events (over 2 hours), the experience of bonking may certainly be related to glycogen depletion. However, the onset of sudden fatigue during short events is more likely caused by spending too much time in the “red zone”. In other words, too much time is spent above the intensity at which lactic acid production exceeds its rate of removal – above lactic (anaerobic) threshold. The tachometer in most standard transmission cars has a red area – usually +6000 rpm. Rev the engine above this too much or for too long and you will most certainly blow up your engine. The human body is much the same. Spend too much time above threshold and you’ll pay the price by “bonking”. The accumulation of lactic acid becomes so great that it begins to interfere with energy metabolism, and the actual contraction of muscle fibres. The muscles and blood are so acidic that coordination is also impaired. This further lends to the sensation of fatigue. Okay, so how do we explain the fact that you recovered within 5K and finished strong? Well, once lactic acid is produced within the muscles, it filters into the bloodstream where it can be neutralized by bicarbonate, or converted to a substance knows as pyruvate which, in turn, is used to fuel other energy-associated chemical reactions. The bottom line is that the body deals with lactic acid quite well, but only to a point. Once an athlete “bonks” due to excessive lactate build up, they are invariably forced to adopt a slower pace which is significantly below the lactate threshold transition point. Lactic acid production diminishes, and the body has a chance to rid the bloodstream of the stuff. Muscle blood flow is improved by the slower pace, allowing lactate to filter more easily into the blood. The result is an almost immediate reduction in the all-too-familiar “leg burn”. Low level aerobic activity helps to facilitate the process of lactate removal, so after 5 or 10 minutes it is possible to begin feeling strong again.

If you severely neglect your diet or have a long, hard training session a day or two before a race, it is quite possible that glycogen stores will be low once you step on the starting line. If this is the case, then you will be limited in your ability to sustain high intensity effort for long periods. In fact, glycogen stores can be so low that they can be extinguished in as little as 40-50 minutes of intense skating.

Based on the above, the secrets to avoid bonking in a race are as follows:

1. Be sure to consume carbohydrate rich foods for 36-48 hours prior to the event.
2. Avoid long duration exercise for a minimum of two days prior to racing.
3. Gauge your exercise intensity carefully so as to not exceed lactate threshold intensity for too long. You can flirt on the edge and occasionally exceed this level, but only so long as you also spend enough time below it to deal with the lactic acid accumulate.
4. Work on elevating the level of your lactate threshold through interval training. This means that you are able to raise your maximum sustainable intensity.
5. Rest well before competing. See page 14 of the printed version of FaSST for more info.

Question:

Why are speed inlines faster than the quad speed skates?

Answer:

There are three primary reasons why athletes are able to go faster on inline skates when compared to quads. For one, there is much less rolling resistance with inlines. This is due to the larger diameter wheels and their elliptical shape. Second, an inline racing frame offers a longer wheel base than a quad. This gives the skater a greater surface area over which force can be applied, allows for more potential power per push, increases traction, and facilitates a longer glide. And lastly, the extended wheel base of an inline racing skate allows for superior technique. Balance and coordination are enhanced, and the skater is permitted to sit back more and initiate the push straight out to the side.

Question:

We were wondering does speed increase or decrease in curves in speed skating?

Answer:

A good question, and I'd have to say that there is no singularly correct answer. There are several variables which can come into play. In most cases, it is certainly possible to accelerate through a turn so that exit velocity is higher than entry velocity. This is often a desirable a thing…work the corners, and relax somewhat on the straights. Keep in mind the following factors:

1. The corner radius. When we crossover through a turn, the direction of force application is in direct opposition to that of centrifugal force. Centrifugal force projects in straight lines, and in all directions from the center of the turn (or more correctly, the imaginary circle of which the turn is a part). In order to maintain the same constant velocity throughout a turn, one must apply the same amount of force, but in an entirely different manner. If we apply more effort than that which centrifugal force presents, acceleration should occur. However, this is often difficult to do as the corner radius is either too small or too large. Too tight a turn and it is very difficult to manage high speeds. Too large a corner and it becomes increasingly difficult to directly counter the direction of centrifugal force using crossover steps. On large radius turns, the skater is forced to push back more instead of straight to the side. As a result, there is considerable wasted energy, and maintenance of speed or acceleration is almost impossible.
   
2. Technique. Being able to accelerate through a turn requires proficient crossover technique. Some skaters are very adept at accelerating through a radius, while others struggle just to maintain speed.
3. Intensity of effort. It should go without saying that corner exit speed can be greater than entry speed if the intensity of effort is increased (assuming the skater has good crossover technique and the corner is not too small or too large).
4. Wind. The direction and magnitude of wind can make it very difficult to maintain speed throughout the duration of a corner. When we skate in a straight line, there are a number of fine-tuning things that can be done to technique that help combat the negative effects of a strong wind. With crossover steps, there is less latitude in that even minor changes to technique can adversely affect force production and therefore speed.
5. Initial corner entry speed. Depending on the radius of the corner, the ease with which one can accelerate is partly related to the actual entry speed. It is often easier to accelerate through a turn, and therefore achieve a higher exit speed, when the initial entry speed is moderate to high, and when the corner radius is of reasonable size.

©Barry Publow, Canada
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