Intermittent Hypoxic Training

October 3, 2010

Even small improvements in performance often take hours of training, hours which for the recreationally competitive athlete are often difficult to find when they have to juggle family life, work and training. One of the most overlooked adjuncts to training that has continually shown performance benefits is intermittent hypoxic training. Intermittent hypoxic training (IHT) makes use of a machine that decreases the amount of oxygen that you breathe, simulating altitude. IHT training has been shown to increase power at both anaerobic threshold and VO2 max by 4-6% in as little as three weeks with daily use of IHT for an hour at a time. This is about the equivalent of six months or more of improvements from actual training for most age group athletes. The real advantage to IHT training is that it is a passive form of training, you sit there attached to the machine and breathe while reading, watching TV or responding to e-mail.

How Does it Work?

Hypoxia, a decrease in the oxygen content of the air you are breathing stimulates the release of erythropoietin, the hormone responsible for producing red blood cell. With repeated exposure you will gradually increase the total number of circulating red cells and the oxygen carrying capacity of your blood.

Many people mistakenly believe that the use of hematocrit, the cell component of blood, levels are a good indicator of whether the IHT is working or not. If you were to take hematocrit measures every day while using IHT you would likely see an increase in hematocrit for a short time and then a gradual decrease back to normal levels as blood volume increases. If you only take a hematocrit reading at the beginning, middle and end of the IHT program you are unlikely to see any changes.

The human body likes to maintain hematocrit within a relatively narrow range, normal variations in hematocrit are typically less than 4% over the course of a year. One of the primary adaptations to aerobic training is an increase in blood volume, resulting in a decrease in hematocrit levels, reducing blood viscosity and resistance to blood flow, and improving cardiac output. There is a strong positive correlation between blood volume and endurance performance but contrary to what many athletes believe there is a negative correlation between hematocrit and performance. In other words high hematocrit levels actually decrease aerobic capacity. A lower hematocrit keeps blood viscosity lower and improves blood flow rate which improves oxygen transportation and transfer of oxygen to the muscles.

Given the amount of time and effort that you put into your training, the investment in IHT training is well worth the possibility of doubling the amount of improvement most people typically see in a year.

References

Thirup, P. (2003). Hematocrit: Within subject and seasonal variation. Sports Medicine. 33(3) pp 231-243.

El syaed, M., Ali, N., and El sayed -Ali, Z. (2005).  Haemorohlogy in exercise and training. Sports Medicine. 35(8) pp 649-670.


Planning Your Program: A New Look at Periodization

July 27, 2010

Periodization is the process of breaking the year into training blocks or periods. Each period has a set of goals and a training focus so that the physical qualities needed for rowing are developed in a logical fashion so that you peak for your main race of the season. Traditional periodized models for rowing focus on the development of aerobic base early in the off season, move to anaerobic threshold level work and then to specific race pace and speed work just before the racing season. While this progression works well for some it does not take into account your individual needs nor does it take into account what types of training you are most ready for. An alternative form of periodization that is becoming more popular is one I like to call Reactive Planning.

Reactive Planning

Reactive planning uses the results of a set of tests to determine training priorities and periodization. Tests are repeated every 8-12 weeks and new priorities are set. Reactive Planning is an examination of how peak anaerobic power, VO2 max, anaerobic threshold, and aerobic threshold compare to each other. In an ideal situation you would expect to see the following relationships: Anaerobic threshold should be 80-85% of VO2 max, aerobic threshold should be 65-70% of VO2 max and VO2 max should be 40-45% of peak power.

Of course if you went to an exercise physiology lab and had all these variables measured you could get a very accurate picture of where you stand but this isn’t possible for everyone. Instead several simple tests you can perform on your own will give you a decent estimate of your proportional fitness. You will need to find all your data using the wattage setting on your erg because it is much easier to do calculations with wattage than it is with time.

VO2 max can be estimated as the average watts from a five minute test. Anaerobic threshold is close to the average watts used during a 20 minute test and aerobic threshold is approximately the wattage that corresponds to a 90 minute steady state workout. Peak power is the maximum wattage you see during an all out 10 second sprint working against a relatively high resistance. Do each of these tests on a separate day so that fatigue from one test does not interfere with the results of another test. Let’s assume you do all the tests and come up with the following data:

Table 1. Sample Data

Test Wattage
5 min 400 watts
20 minutes 295 watts
90 minute 180 watts
10 second sprint 750 watts

From this data we can calculate:

Table 2. Comparing the Sample to the Ideal

Actual Ideal
VO2 vs peak power 53% 45-48%
Anaerobic threshold vs VO2 74% 80-85%
Aerobic threshold vs VO2 45% 65-70%

Interpreting the Data

To understand the data we need to understand the relationship between the physiological points we are discussing and the concept of ceilings. Each of these physiological points can only get so close to the point above before you stop seeing progress. For instance if your anaerobic threshold gets to 85% of your VO2 max it becomes very difficult to move it any higher, this is not to say that you couldn’t get it to 90% but it may take years to get it to do so. You would probably get better race results by focusing your training elsewhere. If your VO2 max scores gets beyond 48% of your peak power you will have a really tough time improving your VO2 until your peak power goes up. Table 2 shows the results of our example and the ideal relationships between the physiological variables.

Looking at the results we see that VO2 max is a higher percentage of peak power than it should be, 53% versus the 45% ideal, suggesting that this person needs to improve their peak power or they will have difficulty improving their VO2 max.

Anaerobic threshold, as measured by a 20 minute test is 74% of VO2 max as opposed to the 85% ideal. This means the person in our example also needs to raise their anaerobic threshold but it is not being limited by their VO2max.

Finally we can also see that aerobic threshold, as measured by the 60 minute test is 45% of VO2 max instead of the 70% ideal, indicating a need for more low intensity long duration work.

Setting Your Training Focus

Now that you have the data and have determined what needs to be trained you can now set training priorities. Peak power always becomes the top priority if it is not within the expected ranges, since it can limit all the other variables. The secondary priority is the area with the biggest percentage difference between your score and the ideal. In the case of our example this would be aerobic threshold, which is 25% away from where it should be.

In our example this athlete would be doing some short very high intensity sprints during their training. It does not matter what time of year it is, their performance is being limited by their peak power so it must be improved before the other variables can reach their full potential. This is not to say they will only do the sprints, rather they become a priority and focus for the next period of training. The other fitness variables like aerobic base, and anaerobic threshold still need to be trained but they are not the priorities. When the tests are repeated before the start of the next training phase there may be a completely different set of priorities.

Reactive planning allows you to modify the traditional periodized training model for endurance sports based on your strengths and weakness and the variables that will be most adaptable. This may mean doing more speed work in the early winter when you may be used to focusing solely on aerobic base building but without addressing your weaknesses first you can spend a lot of time training with very little improvement.


Interval training

July 20, 2010

Interval training is a popular form of training amongst many athletes. While most rowers will use intervals at some point in the year few really understand the purpose of intervals or how get the most from this valuable training method.

Physiology of Interval Training

Interval training involves alternating periods of high intensity work with periods of lower intensity work, usually, but not always above and below anaerobic threshold. By alternating periods of higher intensity work with lower intensity work several things are accomplished:

The amount of high intensity work is maximized. If you were to try to hold an intensity above anaerobic threshold for as long as possible you would fatigue in just over 20 minutes. If you were to do 6 x 5 minute work intervals with a rest period in between you would have done 30 minutes of work above threshold. Since the volume of work above threshold was higher it should give you a greater training effect. The same holds true for VO2 max and anaerobic intervals.

During the work period of the interval you will be producing lactic acid, which your body will have to deal with during the rest period. Active slow twitch muscle fibers are capable of using lactic acid as an energy source. Repeatedly exposing your body to moderate levels of lactate and then allowing it to recover gradually trains your body to become more efficient at lactate removal as you r body develops the enzymes necessary to convert lactate back to glycogen or glucose. This will translate into lower lactate and faster times during a race since you will be able to deal with the lactate as it is produced. Of course this training effect will only happen if you have done adequate base training.

The aerobic capacity of fast twitch fibers is improved with interval training. The more often a fiber is activated the greater it’s oxidative capacity. Interval training is the only ways to activate the fast twitch fibers frequently enough to improve their aerobic capacity, making them behave more like slow twitch fibers.

Designing an Interval Training Program

Interval training is high intensity and needs to be planned very carefully in order to avoid overtraining. The most important component of an interval program is the base work that is done prior to starting intervals. The initial 6-8 weeks of your training should be devoted almost exclusively to low intensity long duration training, 60 minutes or more per session. This will prime the slow twitch fibers and improve their fitness, so that they can accept the lactate that will be produced when intervals are started, allowing you to make effective use of interval training.

The Work Period

The duration of the work period will vary depending on the intensity of the interval. A work load just above anaerobic threshold will need long intervals, 5-10 minutes, while higher intensity anaerobic intervals can be as short as five seconds. Consistency is the most important factor in interval training. The power output or split time should be the same for each work piece of an interval session. In other words if you are doing 5 minutes at 1:55/500 on the first interval all other intervals should be done at the same pace. This ensures that you are maintaining the appropriate intensity and recruiting the same muscle fibers in each interval, improving the training effect. It does very little for you to do an interval session where the first interval is 1:55 the next is 1:59 the next 2:02 etc. Be sure to choose an interval duration and split time that allows you to be consistent throughout the workout.

Choosing paces for the work intervals requires a little up front work on your part. You need to have an idea of your splits for both anaerobic threshold and VO2 max. Procedures for determining these points were set out in my article “Is Your Training Focused Properly?” published in IRN February 2003. Training splits will normally be set at anaerobic threshold, VO2 max or half way between.

The Rest Period

The rest period is as important as the work period. The purpose of the rest period is to allow time to remove the lactate created during the work interval, and allow the anaerobic alactic energy system to replenish itself. During aerobic intervals, intervals longer than two minutes, the rest period is active, meaning you continue to row but at a lower intensity. The duration of the rest period will depend on the duration and intensity of the work period. Aerobic intervals will vary for a 1:1 to a 1:4 work rest ratio. Anaerobic intervals were covered last year in another article. When choosing the duration of your rest period, follow these simple guidelines: 1). The longer the work the shorter the rest

Longer intervals are normally done at lower intensity, requiring a shorter rest period. A five minute interval just above anaerobic threshold will produce moderate levels of lactate requiring less time to recover so a 1:1 or 1:1.5 work to rest ratio can be used. A higher intensity two minute interval will produce more lactate and therefore require a longer recovery. 2). Adjust the duration of the rest period so that you can maintain a consistent split during the work period. It may happen that you decide to do 5 minutes of work followed by 5 minutes of rest, repeated 5 times. Half way through the workout you notice that you can’t hold the same work split. Finish the training session, coming as close as possible to the desired splits. For the next session increase the duration of the rest period by 50%. If you still cannot hold the desired splits for all the work periods drop the splits for the rest period by about 10% for the next workout.

Table 1: Work and Rest Period for Various Interval Intensities

Type of Interval

Work Period

Work:Rest

Notes

Anaerobic Threshold 3-10 min 1: 1 or 1:1.5 Just above and just below threshold
Supra threshold-Sub Max 2-7 min 1:2 or 1:3 Halfway between AT and VO2 max. Recovery in Zone 1
VO2 max 1-4 min 1:3 or 1:4 Work at VO2 max recovery in Zone 1 VI
Anaerobic Sprints 5-60 seconds 1:6 All out sprint passive recovery

Most rowers who race 2000m will use some combination of all four types of intervals in their training program. For those rowing 1000m races the VO2 max and anaerobic sprints should make up the bulk of your interval training, while those doing only head races will focus their interval training on anaerobic threshold intervals.

While interval training is a great way to improve speed, it is easy to overdo it and do yourself more harm than good so take it easy when starting by doing only one session per week and increasing by one session per week every two weeks until your are doing at most four sessions per week.


Beta Alanine Supplementation

July 7, 2010

If you pick up any fitness magazine or walk into any nutrition store you will find dozens of products that claim to improve performance, with more showing up on the store shelves every month. In most cases the claims are exaggerated with very few products actually improving performance. Every now and then however a product does come along that lives up to the hype; about twenty years ago that product was creatine, which has gone on to become the most researched performance enhancing supplement with the vast majority of studies supporting it’s use in most athlete groups.  Recently another product has started to show that same type of promise: Beta alanine. Beat alanine supplementation has been reported to decrease fatigue associated with higher intensity exercise.

Fatigue during Exercise

Fatigue, defined as the inability to carry on a given level of work, is a complex phenomenon with many factors contributing simultaneously. While the inability of the nervous system to activate muscle fibres, interference with calcium release or uptake within the muscle, structural damage to muscle fibres, heat, and depletion of energy stores are some of the main culprits, an accumulation of metabolites like ADP, inorganic phosphate,  lactate and hydrogen ions are among the most well known contributors to fatigue.

There has been an ongoing debate about the role of lactate in fatigue. Research conducted in the 1970s suggested that lactate was a major contributor to fatigue. Many of these studies were correlation studies that did not look at cause and effect. While there was a correlation between the amount of lactate that was produced and fatigue more recent research has shown that lactate itself does not contribute to fatigue and may actually work to prevent fatigue. The production of hydrogen ions, from various sources in the series of chemical reactions that take place when the anaerobic energy systems are used, can lead to a decrease in the pH of the cell; interfering with energy production and muscle contraction.

Buffers

Buffers are the body’s chemical agents that keep pH in the cells within normal range. There are a variety of buffers that the body uses. Bicarbonate is the most important extracellular buffer, meaning that it maintains the pH outside of the cells. It has been known for many years that ingesting sodium bicarbonate, baking soda, can increase the effectiveness of the bicarbonate buffering system in the body and delay fatigue in high intensity sports. For many people ingesting baking soda causes stomach problems and can lead to vomiting or diarrhoea, unpleasant side effects at the best of times but particularly problematic during competition.  Carnosine is the primary intramuscular buffer found in humans, it also seems to have positive effects on the nervous system, acts as an antioxidant and may have anti aging effects.  Carnosine does not appear to be increased by exercise  but supplementation with Beta Alanine does increase intramuscular carnosine and improve buffer capacity.

Effects on Performance

The majority of studies suggest that beta alanine can enhance performance in sports where there are maximal or near maximal efforts for 60s to 5 minutes. Shorter duration sprints and strength training do not seem to benefit as much from beta alanine use, although total work volume in strength training sessions can be improved by as much as 20% following beta alanine supplementation. Whether the increase in work volume can translate into better training adaptations and performance improvements is not known. Two studies have shown improvements in power at anaerobic threshold following beta alanine supplementation and slight improvements (2.5%) in time to exhaustion at anaerobic threshold.

Supplementation Protocol

Several studies have been done on to find the optimal protocol for taking beat alanine. It appears that ability of beta alanine to increase carnosine is dose dependant, 6-7 g per day give best results. Beta alanine supplements often cause tingling sensations in various parts of the body, particularly in the head and neck region. This can become quite intense and unpleasant if large doses are taken at one time. The tingling can start within minutes of taking the supplement and last for up to an hour.  Smaller doses spread throughout the day or time release capsules seem to decrease or eliminate the tingling. Beta alanine supplementation is not an acute response supplement it needs to be done over an extended period of time for significant effects to be noticed, usually 28 days or more.

Adverse Effects

Currently the only known adverse effects associated with beta alanine supplementation is the tingling that is noticed shortly after taking the supplement.

References

  1. Allen DG, Lamb GD, Westerblad H. Skeletal muscle fatigue: cellular mechanisms. Physiol Rev. 2008;88(1):287–332.
  2. ARTIOLI, G. G., B. GUALANO, A. SMITH, J. STOUT, and A. H. LANCHA, JR. Role of A-Alanine Supplementation on Muscle Carnosine and Exercise Performance. Med. Sci. Sports Exerc., Vol. 42, No. 6, pp. 1162–1173, 2010
  3. Boning D, Maassen N. Last word on point:counterpoint: lactic acid is/is not the only physicochemical contributor to the acidosis of exercise. J Appl Physiol. 2008;105(1):368.
  4. Cairns SP. Lactic acid and exercise performance: culprit or friend? Sports Med. 2006;36(4):279–91.