Tag Archives: human physiology

Iron and Endurance Performance

Iron is perhaps one of the most important nutrients when it comes to performance. This is due to it’s role in transporting oxygen through the blood. Iron has several forms within the biological system but in this case Haemoglobin is an Iron containing protein which Oxygen binds to. Iron is absorbed in the gut and transported to cells. Once it has been taken up in the formation of Heamoglobin it is ready to go to work.

The main determinant of endurance performance is oxygen supply to the working muscle. A muscle cell is capable of producing much more energy in the presence of adequate oxygen than without. Once oxygen demand exceeds oxygen supply, the level of intensity becomes finite. This is a major process when we consider fatigue. A huge proportion of our training aims at increasing oxygen supply and making our metabolic and circulatory system as efficient as possible. Endurance performance is determined by our movement and metabolic efficiency and our capacity to support them. In other words we try and reduce the oxygen cost and increase the oxygen supply. If we can achieve this we will perform, and enhance our performance ability.

Given the importance of oxygen and oxygen supply, Iron now takes quite an important role in the system. Without adequate Iron levels we will have reduced oxygen supply capacity within the blood. This was displayed in recent years with athletes who were involved in blood doping. Individuals who utilized substances which increased the production of red blood cells noticed some complications. Without a reflective increase in Iron any oxygen supply increase would be limited. Heamoglobin is a major constituent of a red blood cell. As a result Iron supplementation became common in unison with the use of these drugs.

One other such instance is in Female athletes going through menstruation. Blood loss and subsequent loss of red blood cells will impact endurance performance. It has been well documented that female athletes need to be vigilant with their dietary Iron intake. Those who fail to do so can easily become anaemic. Anemia is a disaster for any endurance type sport. Ability to perform is dramatically decreased and can be improved very rapidly when iron intake is increased.

What many athletes are not aware of is the fact that red blood cells can be easily damaged during exercise. This degradation is known as Haemolysis. Haemolysis can reduce our levels of haemoglobin and our overall capacity to supply oxygen. How this Haemolysis occurs is debated somewhat. Some feel the main mechanism is a breakdown of the redblood cell’s lipid layers which encase the contents of the cell. This occurs in the presence of free radical ions in the blood produced through oxidative metabolism, A process which is significantly increased during exercise.

During high impact exercise we can also damage the cells causing their contents to burst out into the surrounding blood plasma. This can occur in impact sports but usually not on a large enough scale to cause problems. Highly repetitive exercise such as running where the feet are hitting the pavement thousands of times can get to a point where significant hemolysis has occurred. At extremely high intensity there can be increased pressure on the renal system. Breakdown of tissue leaves proteins, sodium and other ions in the blood. The kidneys filter the blood but can become clogged up with these molecules. Iron can be forced into the surrounding tissue. This can result in renal failure. Dehydration can also contribute to all of these processes.

Extreme duration events have been associated with quite significant Haemolysis.

During heavy or prolonged exercise all of these processes may occur to some degree. Studies examining long duration races such as Ironman and Ultramarathons have all been used to examine the changes in Iron levels. 95% of individuals showed a significant reduction in Iron post event. Even shorter distances showed a high prevalence of altered pre/post event Iron levels.

The lesson in all of this is that during exercise we do deplete our levels of Iron. This is in isolation of any preexisting health issue or consideration. Given the importance of iron in our ability to perform it becomes clear that it is a nutrient that must be a constant consideration for any athlete. Many athletes have disregarded their Iron intake and pay a massive price knowlingly and unknowingly. It is a nutrient that gets some attention but rarely to the full extent it deserves.

All athletes who wish to perform at their best need to ensure that they support their efforts nutritionally. Macronutrients often shadow the role of micronutrients in the diet. Iron is one which simply cannot be overlooked. If in doubt consult professional nutrition support. It can easily bring you the progress you’ve been looking for.

Exercise performance in the heat!

As it is coming closer to the summer months here in the Northern Hemisphere, now is a good time to discuss how heat influences performance. Paula Radcliffe is possibly the greatest example of heat stress and performance. Her race at the Athens 2004 Olympic games was a disaster. She blamed the extreme heat for her lack of performance at a period where she appeared to be in great racing form. Heat exhaustion also claimed several top athletes at the 2015 Crossfit Games. It is an often overlooked and significant concern for many athletes.

As we exercise, the by-product of metabolism is heat. This heat production raises our body temperature. Our body tries to maintain a range between approximately 36-37°C. It has several mechanisms to do this including sweating and directing blood flow to the surface of the skin. This helps dissipate heat through evaporation. If temperature rises above this range, safety mechanisms in the form of temperature sensors in the body will intervene. Your body will actively try to reduce its activity in an effort to slow you down to the point at which it can get temperature level back under control.

In terms of endurance, cardiac output is a major determinant of exercise performance. If we sweat, the water in our blood plasma is reduced. Cardiac output will reduce and endurance performance will be diminished. For this reason we try to maintain our hydration as best as possible. The hotter the ambient conditions the more we need to drink to replace lost fluid and maintain our performance capacity. If we drink large amounts of water and sweat a lot, we run the risk of excreting a lot of salts which are in sweat. If we do not maintain a salt/water balance we can start to experience cramping in the muscles. Often athletes drink until urine has a very light yellow colour. This is generally a pretty accepted method of monitoring your hydration. However, if we do not replace salts we can achieve light coloured urine relatively quickly but without properly reaching hydrated status. In the case of extreme heat and sweat adding a hydration tablet or isotonic fluid is beneficial. It not only replaces salts but can help rehydrate as fluid is absorbed more efficiently when it has isotonic concentrations of electrolytes.

An important factor to consider in the heat is the relative humidity. Humid conditions are much harder to cool down in as sweat and evaporation are not nearly as efficient. It is also good to consider the fact that in dry conditions sweat may not be as noticeable as evaporation is quite rapid. In both cases we can lose a lot more sweat than we think. As fluid loss is so detrimental to performance it is essential to maintain a strategy of drinking and staying hydrated and be aware of the conditions.

In terms of warming up, an increase in body temperature is extremely beneficial to muscular contractility. If our temperature is too high though it will have a very negative effect. In extreme heat remaining cool may be more important than increasing temperature before a race. It is even more important to manage heat during competition especially in longer events. Wearing light coloured, light material clothing can help reduce heat from the sun. Precooling using a cooling jacket, cold drinks or dampening your clothes can also help keep body temperatures down in hot conditionings. Overheating during a long race can have disastrous effects. In Paula Radcliffe’s case it was likely her extensive warm-up in the heat raised her temperature to a point where she could no longer manage optimal temperature when the race started-Something which would not have been an issue racing elsewhere.

 

Heat exhaustion can creep up on you and put an early end to your competition. It can also be extremely dangerous.

Heat exhaustion can creep up on you and put an early end to your competition. In can also be extremely dangerous.

It is rare that many athletes experience truly extreme heat as many event organizers take safety into consideration. However, sometimes we compete in foreign regions and some athletes are more accustomed to hot temperatures than others. The heat can have a very significant impact on performance. It is essential that athletes always consider the competition environment and have strategies that allow them to be at their best. It is always good to be prepared. Always bring a cap and light coloured shirt to competitions. Sunscreen and water are essential to a competition kitbag. Conditions can change fast and the simplest forms of preparation can make all the difference.

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Recovery Tools: Active Recovery!

Recovery has become a core factor in every athlete’s training and success. There are many recovery methods which can be employed all targeting different things. Not all methods work well for everyone and people will have their favourite. This is normal as the processes of each method are slightly different. Some things will simply have a better effect on certain individuals than others. One popular and convenient method is active recovery. In terms of effect it appears to be relatively beneficial to everyone.

When we exercise we produce metabolic by-products. These by-products can interfere with muscle contractions and contribute to fatigue. While we exercise we have a system to clear these by-products and consume them. When we stop, the rate of clearance reduces and they can be left to accumulate. Eventually they will be cleared up but at a reduced rate. Some gentle exercise post training can help ensure these metabolites are cleared effectively.

When we do more intense muscle contractions where a lot of force is applied, muscle stiffness can occur. Stiffness is when the fibres fail to fully relax causing a temporary shortening of muscle fibre length. Gentle movement can help break up this tension and reduce stiffness. Active recovery can be quite effective in doing this. The submaximal contractions allow the fibres to relax back to resting tension.

Another mechanism it can influence relates to bloodflow and temperature. In order to repair damaged muscle cells after intense exercise they need a good supply of nutrients. This supply comes from the blood. Increasing bloodflow to tired muscles ensures they get a good supply. In addition increasing local muscle temperature can help the muscle fibres loosen up and restore contractile function. Gentle exercise activates the muscle pump which flushes blood through the muscle as it contracts and relaxes.

These three mechanisms have some quite favorable benefits on getting back to top performance in a short period of time. An important factor and one which many people get wrong is when and how to do active recovery. Active recovery first and foremost should not contribute further to fatigue. Intense exercise is not recovery; it is simply another session. Often people perform hard conditioning instead of resistance training believing it promotes recovery. While some aspects may have a similar effect, the benefits are cancelled out by the increased metabolic and cell stress. A reliable intensity to work at is 50-60% of Heart rate reserve. The session need not be any longer than 30mins to be effective. We recommend low load bearing exercise to reduce any further stress on joints etc. Swimming, crosstrainer and biking are excellent choices.

Deciding when to employ active recovery is also tricky. In most cases we should employ some sort of short active recovery in our warm down procedure. This allows us to clear metabolites immediately after a session as well as stabilizing core temperature in a more gradual manner. Some like to use recovery sessions on their day off. In this case promoting bloodflow and reducing stiffness are the main mechanisms. This scenario is problematic as one must refrain from turning recovery into more conditioning work. While for some, running and rowing may be suitable, many heavier athletes will actually induce more fatigue and joint stress using these exercises. A 5k run is not a recovery session it is aerobic training, while less intense it simply applies a different type of stress.

It is important for athletes to understand the purpose of active recovery and the mechanism by which it works. Just because a session is of lower intensity it does not automatically become recovery work. The sole purpose of active recovery is to promote a restoration to a rested state and therefore maximum performance potential. It has a clear purpose and application. Smart athletes recognize the difference and they reap the rewards of using it effectively.

Alcohol and athletes!

Check out our recent article on how alcohol interacts with our body during training and competition. As featured in BOXROX magazine!

http://www.boxrox.com/alcohol-crossfit-performance/

6 Ways to Remove Metabolites and Recover from a Hard Workout

Article on metabolite clearance post training as featured on BOXROX magazine.

Follow the link to the article

http://www.boxrox.com/6-ways-remove-metabolites-recover-hard-workout/

The critical factor to gaining muscle!

There are thousands of young athletes desperately trying to increase lean muscle mass. There are also an equal amount of training programs, diets and supplements which promise results. With these distractions it can be easy to overlook the basics. In the end the basics are what will get real results.

Most of us are now familiar with the concept of hypertrophy. When we lift a heavy weight, the tension placed on the muscle fiber during a contraction causes microscopic tears. The body reacts to this by repairing these tears and increases the size of the fibers. This adaptation allows us to react to, and survive the stress placed on us. This cycle can be repeated with training, eventually producing noticeably bigger, stronger muscle. As we adapt to a level of training we must progressively increase the level of stress to continue to progress.

The body can only repair itself when at rest. Structural repair will also take a certain amount of time to occur. If we apply further stress too soon after a session we only cause more trauma, not adaptation. When looking to increase muscle mass it is important to be well recovered on a regular basis. If we train too frequently without rest, results will be mediocre. Generally, because we see reasonable progress from training we assume more will be better. There comes a point where we are doing too much and lose sight of the process we are trying to promote.

The fact is that there is only so much the body can cope with. New muscle is created during rest, not during training. If we train too frequently there is no opportunity for the growth to take place. An athlete must be aware of this and schedule rest days as part of a hypertrophy program.

The best approach is to start with a simple hypertrophy focused program and progress things slowly. The trick is to remain patient and stick to a plan. It is very easy to get excited and add extra sessions, thinking it will accelerate progress. Recovery needs to be as much a priority as the training itself. If an athlete neglects recovery and rest they will put themselves at a great disadvantage.

When looking to gain lean tissue an athlete must follow a gradual progressive overload program. They must ensure rest and adequate nutrition. Hypertrophy is a slow process and patience is key. There are no magical programs. A coach must monitor the athlete to ensure that he sticks to the process. Young athletes must be especially careful as their inexperience can create insecurities with the program. In a competitive environment, where team selection may be a factor, athletes must learn to trust the program and commit to it.

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Jetlag and the athlete!

It is common for athletes to travel long distances for both competition and training. Seasonal differences may make travel essential in sports where weather is an important factor. Jetlag becomes an issue when an athlete has to cross multiple time zones. The reason is that human circadian rhythms are not synchronized with the surrounding environment.

This post will discuss the cause of jetlag, the impact it may have and some ideas for managing it. In addition to jetlag there are other travel related issues that can contribute. I will discuss those separately as they deserve direct attention.

The body clock is a system which co-ordinates hormones in our body in response to environmental factors. This allows our body to cycle through periods of readiness and rest. It is essential that we have this ability to avoid over stressing our systems. Sunlight is one of the major influences in this cycle. When we wake in the morning sunlight stimulates the suprachiasmatic nuclei (SCN) through the retina of our eyes. This is basically our start up switch for the day. When the sun sets, the pineal gland, which is linked to the SCN, is stimulated to secrete melatonin. This hormone promotes sleep. During daylight this secretion is suppressed. This process can also be influenced to a lesser degree, by artificial light. The body clock disruption also impacts other natural body rhythms such as body temperature, blood pressure and appetite.

This disruption to circadian rhythms can cause sleep disturbance, fatigue, disorientation, headache, loss of appetite and a generally poor mood state. It is not unreasonable to believe this will cause a decrease in motivation in the athlete. Decreased alertness and readiness to perform have obvious implications for performance.

In terms of management there are a few ways to totally avoid jet lag. Serious athletes need to make a record of their experiences with jet lag and how they feel and cope individually. Each athlete is different and there are varying degrees of susceptibility to the symptoms. Some find the effects lessened depending on direction of travel. Eastward travel appears to have the greatest impact on jetlag.

It is generally accepted that for each time zone shift. 24hrs is required to return to normal rhythms. If possible an athlete should plan to arrive at a venue with this time frame in mind. If they travel through 7 time zones then they should aim to arrive with 7 days to adjust back to normal. In addition the athlete should try and adopt the schedule of the new time zone as soon as possible. This means setting their watch to the new time and making an attempt to eat, sleep and exercise on this new schedule. Some of this may be possible in the weeks leading up to travelling. For example an athlete can train later in the day or go to bed a little later etc. This may be advisable when they are travelling close to competition without adequate time in the new venue.

The main focus should be on adjusting as fast as possible to the new time zone. The effects of jetlag are hard to avoid. Instead of trying to ignore or avoid it, an athlete should accept the situation and learn to manage it. Over time the individual will learn what works best at minimizing the effects allowing them to perform at their best. Hopefully these strategies can help them to do this.

Building the engine!

Our cardiovascular system is basically an engine. The bigger it is the more power we can produce. Like any powerful engine its performance is based on its efficiency and size. When we look at our body in terms of conditioning we should think of it like an engine. We must first build it and then fine tune it to be efficient for what we want it to do.

When we look at training we can look at it the same way. First we need to assemble the basic parts, this is the base miles in the offseason. This is what promotes the structural changes in our physiology. Our heart becomes larger and more powerful, capillarization occurs improving blood supply to the muscle fibers and in addition numbers of mitochondria increase within the cells. This process is gradual and is stimulated by large volumes of aerobic training. It is a relatively slow process but has a long lasting effect. Because longer duration is required the intensity must be relatively low in order to accumulate adequate volume without overtraining. This will gives us the foundation for our conditioning. Increasing aerobic capacity also has a vast amount health benefits associated, such as reduced blood pressure and a strong and efficient heart.

Once we build up a foundation we must then tune it. Now anaerobic style training comes into play. Anaerobic training up-regulates enzymes which promote glycolysis, the energy system utilised during high intensity. It also improves the ATP-CP energy system used during sprint type activity. The effects happen over a much shorter period of time and remain effective for a short period if training is not maintained.

HIIT has become popular because it yields results much quicker than LSD training. The issue is that the physiological changes that come from it are really only the icing on the cake. Without a strong base prior to HIT an athlete is neglecting a big part of their physiology. This is noticeable in a lot of team sports. An athlete may perform quite well at high intensity but struggle to utilise fat for fuel, causing him to tire late in a game. They also tend to recover relatively slower as their oxidative system does not have the capacity to remove lactate as effectively.

Rocky-Elsom-hands-on-head

Athlete catching breath between play. Source:http://www.rugby365.com

If an athlete wishes to have good conditioning for their sport they must build a big engine to begin with and then tune it to be suitable to their activity. Whether they use threshold work or sprint intervals to do so will depend on the nature of the sport. The point I emphasise is that a strong aerobic base should never be neglected. Regardless if the sport is an endurance sport or not a strong aerobic system will be of great benefit to most athletes as it is still a major part of their physiology.

Recovery! Part 1

Recovery is a particular interest of mine. It is one of my main research areas. We are currently researching different recovery interventions on isometric strength, fatigue and performance. Over the coming months I will discuss different aspects of recovery and some of the methods that can be used. For this post I’ll discuss the importance of recovery!

When it comes to training human knowledge has covered most training methods that technology and equipment can provide us. How we plan and organise training still has some room for improvement but in general there’s not many new training concepts. Recovery has now become a major area of focus as in comparison, it is still a very new area for research. So why is it important? The simple answer is because it makes a difference. In terms of human physiology our body responds to stress and adapts. These adaptations are what improve or conditioning, strength, speed, power and so on. All training is based on the General Adaptation Syndrome (GAS) theory. A stress is applied impacting homeostasis. The body responds to this and resists the stress. It then forces homeostasis past its starting point as a defence mechanism and a new level is set. It is the recovery stage that actual improvement takes place. If you deny yourself this improvement it will eventually lead to overtraining and burnout and certainly kill performance as homeostasis is depressed.

A professional athlete trains full time. He can train all day long without commitments to work or study etc. Often, newly turned full time athletes take the approach of rapidly increasing training volume. They are so used to struggling to fit in training that when they graduate or move into a professional setting they can easily do more. What they soon realise is they plateau. Without proper coaching they can continue on this path for months and even seasons becoming disheartened by poor performance. What they fail to realise is that recovery is just as important as the training. Being full time is what allows them to dedicate time solely on recovery which befits their training level. In many sports there is a finite amount of time to prepare. Looking at the olympics as our example. An olympic athlete may train 5 days a week for 40 weeks of the year. 5 days per week is all he can cope with. Lets say he employs a recovery strategy that takes him from 5 days to 6 days per week. He has just increased his annual training by 40 days. 40 days is an enormous amount of time in terms of competition preparation. Something that may take 15mins post training has just allowed him to train 40 days more than his fellow competitors. When you rationalise it in this way you can see the difference it can make come competition time.

Athletes make recovery a part of their schedule. Here using commercially available compression technology!

Athletes make recovery a part of their schedule. Here using commercially available compression technology!

A good athlete will be just as concerned with their recovery as with their training. There are many forms of recovery playing on many physiological responses. I will cover these in other posts and discuss some potential methods and how they work.

Fat loss for athletes!

Body composition and body mass are important for most sports. The success of an athlete can rely heavily on falling within the norms of their sports, especially where a weight category is involved. Nutrition and training are both vital in the role body composition and weight management. I will not discuss dietary strategy as it is not my are of expertise. Instead I will discuss the training considerations and strategy.

Step one is for an athlete to identify whether he needs to reduce bodymass (weight) or reduce body fat. Bodymass deals directly with bodyweight on the weighing scale with no concern for body composition. Body fat deals with body composition with possibly no influence on overall bodymass. When reducing body mass the main focus, is to create a consistent calorie deficit. How one trains doesn’t really matter as bodymass will decrease over time if calorie expenditure exceeds consumption. The issue is that this reduction will not be selective in terms of tissue loss. Both muscle and fat tissue will be lost but this is not such a good thing. In many cases an athlete will need to retain as much lean mass as possible and may even need to increase or at least maintain it. This creates a more complicated scenario where fat tissue must be the focus for reduction while avoiding any muscle tissue loss. The training strategy becomes a little more complex.

We know that in terms of metabolism, exercise at lower intensities utilise fat as fuel more effectively than high intensity exercise. The main drawback is that in terms of time efficiency it takes a relatively long period to burn sufficient calories. The other issue is that low intensity work can promote adaptations that are not so favourable for an athlete. Long periods of low intensity (LSD) training can promote a conversion of type 2 muscle fibers into fibres which more resemble the characteristics of type 1 muscle fibers. The athlete runs the risk of losing strength, speed and power. So this method must be used sparingly.

High intensity training has been touted as the magic pill for fat loss and performance in recent literature. Calorie expenditure is higher for a given work period and metabolism is elevated in the post training period. Sessions must, however be shorter as they will be more demanding. It is in this post training period where an elevated metabolism and active oxidative system plays its role in metabolising fatty acids. HIT may also promote strength, power and conditioning through a number of adaptive responses. At first glance this seems to be the obvious choice. As with most training methods it carries its disadvantages. By focusing on HIT we become reliant on the Glycolytic system during exercise. This system utilises carbohydrate metabolism and is always active even at rest when the oxidative system is dominant. Over time an athlete may promote the use of carbohydrates during metabolism which will in fact spare fat cells. If they do not consume enough carbohydrates there can also be a reduction in lean tissue as muscle cells do not get enough energy to survive.

The best strategy is to utilise both methods in an appropriate fashion. LSD can be made more effective in reducing fat and improving fat oxidisation by adding fasted LSD sessions into a program. Done before breakfast or immediately following a training session, enzymes active in fat oxidation must up-regulate to compensate for glycogen depletion. This means that less time is needed to initiate fat oxidation. HIT should then be performed in a fuelled state in a separate session to make use of its benefits. When both types of sessions are used in a balanced way that does not impede the athletes recovery, they can see all the benefits while negating the disadvantages.

As with most strategies a balance is required for optimum results. The body is exceptional at adapting to stress. Overemphasising one method over another will only display short lived success and may create problems in the long run. In the case of managing body weight and body mass a strategy must be formulated to suit the needs of the individual. A gradual and monitored approach is best for achieving long term and consistent results.