Wednesday, 31 October 2012

Energy Systems. What's happening to those macro nutrients when I run, bike or swim?

We have seen from the post "Nutrition 101" that our bodies are programmed to store fat and as a consequence of that we will burn carbohydrate before fat if both are available. Since carbs yield less than half the energy of fats, the question is "how can I access those fats for burning which will yield more energy and make me look in better shape?"
Since this is primarily a running blog lets take running as the example here but the story is the same for cycling, swimming and any other endurance activity.

The muscle cells store a small amount of glucose as does the liver. As we sit in work, lay in bed or watch TV our bodies use these glucose molecules for energy production, the energy is required to keep us ticking over (think of a car with the engine turned on and it's sitting still). This energy equates to our basal metabolic rate (the amount of fuel you will need to put in the car to keep the engine ticking over), as we get up from our desk, climb out of bed or get up off the sofa these muscle glucose stores will be burned up very quickly. The daily activities we do all require energy (remember the car, now you are beginning to press the accelerator) and this energy added to the basal metabolic energy equates to our metabolic rate (or metabolism). If you have eaten any carbohydrates you will be replenishing these stores all the time until you begin to run!!!
So you start running and you feel good for about 10-15mins because you have a lot of easy access glucose to burn. The part of the cell that converts glucose and oxygen into energy is called the mitochondria (think power station) and the trucks carrying the fuel to the power station are full of newspaper, fast burning low yield energy. Then from 15-20mins you feel like crap because your fuel stores are running low and your energy plummets. But then at about 20-22mins (you put some big wood logs on the fire) you start to burn the fats. Now your energy will increase and you will begin to feel good again. This energy surge will now depend on the amount of power stations you have active in your muscles.
If you increase the number of workouts and/or the duration, your muscle cells will build more (mitochondria) power stations and you will (like the Duracell Bunny) go for longer.

If you are new to running you need to understand that this will take some time and most importantly regular running however short the distance. If you are a runner but have taken some time off, the power stations are shut down if they are not used that's why you can no longer run as fast as before or for the same distance. It will take 2 -3 weeks of regular running to get your power stations reopened and fully functional.

If you keep your metabolism quite low by doing very little exercise the carbohydrates you eat will always prevent your fat stores from being used as fuel. This will give you low energy and you will feel tired and cold (newspaper burning does not give off heat for very long) most days. Some of the  carbs that are not burnt will be linked with fatty acids and stored as fats (no need for water). So yes carbs can and will be stored as fats. Excess carbs that have not be burnt or stored as fats are excreted (calories down the toilet). Another reason why calorie counting is an arbitrary weight loss plan.

The next entry I will discuss, how running can be used to lose weight and how you go about maintaining weight loss!

Tuesday, 23 October 2012

Nutrition 101! Running

As a runner it is important to understand nutrients otherwise you can never develop an appropriate diet to fulfill your demands. A sufficient diet is the first and perhaps most important step in preventing injuries.

To begin with we need to understand that there are 3 macro (large) groups of nutrients. There are carbohydrates, fats and proteins. Everything in your body is a combination of those three macro nutrients, so yes you are what you eat,,, but not really! Because when you eat foods you break them down into micro (very small) nutrients before ingesting them into your body. Once these micro nutrients are ingested our liver and some special cells around the body can build the products they need using these micro nutrients.
Carbohydrates get broken down into simple sugars most notably glucose. Fats get broken down into fatty acids and proteins are broken down into amino acids. This seems like a lot of hard work breaking foods into micro nutrients only to build them back up. However it is essential because our bodies recognise all our proteins (as self proteins) so we don’t attack them with immune cells (antibodies). If we ingest another animals proteins (these would not be self - foreign proteins) we would have an immune response every time we had a meal. “Not Good”. So we break protein into amino acids and rebuild those back into (self) proteins in the liver!
The presence of a foreign is why we get sick (Fever, Pain, Inflammation, Nausea) when we have a bacterial (small organism secreting protein) or Viral (small piece of RNA or DNA with a protein coat) infection. These proteins are foreign and our bodies go to war with them which makes us feel weak and tired.

If we look at the calorific value of these macro nutrients we see that:
Carbohydrates yield 4 cals/gram
Proteins yield 4 cals/gram
Fats 9 cals/gram

A calorie is a unit of energy so measuring calories I believe is a totally arbitrary way to try and lose weight because the end result of each macro nutrient is different therefore the calorie count gets very difficult to monitor. Let me explain!

A calorie (in food terms) is the amount of energy it takes to increase a kilogram of water by 1 degree Celsius. So to discover the amount of calories in any food all you need to do is put it in a glass box under a kilo of water, set it on fire and measure the increase in water temperature when all the food is burned and work out the amount,,, or read the label!

Our bodies are programmed to store fat whenever possible, this is a unique mammillary trait to have as much stored energy in case of times of famine, since we now know fats yield the most amount of energy (9 cals/gram) they are the best to store. But what happens if you store too much and there is never a famine??? You get fat!
This programming also means that whenever carbohydrate is available, it will be burnt before the fats. This is achieved by the release of insulin from the pancreas (insulin tells every cell in you body to burn glucose instead of fat). Our bodies do this because fats are not water soluble and carbohydrates are, therefore you would need to carry a lot of water around if you were to store carbs like the way you do fats and with a low yield of energy (4 cals/gram) it just isn’t worth the time.

Carbohydrates are the easiest to burn up for energy (think of newspaper) but don’t last long, fats are more difficult to burn up (think of wood) and last a long time. Proteins are rarely used for fuel and are more difficult to burn than carbs (think of cardboard) with a relatively low yield of energy too.
The first indication that you are burning proteins as a source of fuel is the smell of amonia from your training clothes after you have finished a run or cycle. You may also develop sores at the side of your mouth or mouth ulcers. There are many more signs but these are the most noticeable. You might want to ensure you are eating the correct amount of carbohydrate and fats to minimise this. Proteins are the building blocks of the body and its never a good idea to smash up the blocks in the walls of a building.
Proteins are not stored in the body so whatever is not used is excreted therefore it’s pointless counting those calories!

The next time I will explain how you go about ensuring that you are in fact burning the fats when you are running! Isn't that what we all want to do?

Thursday, 18 October 2012

What does it mean when I am injured?

As runners we are all predisposed to getting injured and sometimes at a slightly higher chance than the sedentary population. But here is the catch,,, runners and fellow exercisers are more likely to recover faster and with better outcome than the sedentary population. Or to put it more simply,,, if a sedentary person gets injured the outcome may well be complicated.
The first implication of any injury or pain is that the body has reached its limit of adaptation. What this means is that at some point something happened which caused your body to alter the way it functions. This may have been a very minor and unnoticeable  event or it may have been something you remember. however something changed and your body would have began to adapt to this change.
If the causation of the adaptation was not resolved (either by your bodies ability to repair itself or by manual therapy) eventually your bodies ability to adapt will fail and injury or pain will be the result.
The initial event is what we refer to as either a predisposing or maintaining factor and this is what we as Osteopaths look for in the case history, it maybe something that can be corrected or it may be something that you have to factor into your lifestyle to avoid further injury,,, let me explain!

If you had a predisposing factor to the injury such as a structural change; slight curve in the spine or a slight leg length difference or an previous fracture then you will need to manage you condition and know your limitations to avoid further injury. However if there are no major predisposing factor and therefore no structural changes in the body as mentioned above, the mechanism of injury will be due to a maintaining factor. Maintaining factors are day to day habits and activities such as sitting with your legs crossed, poor posture and muscle strength, inappropriate footwear, inflexibility or running on uneven terrain to name just a few. You need to correct or remove this factor otherwise you will be prone to multiple injuries of the same muscle or joint OR further injury to more muscles and joints.
Injury by maintaining factors seem to be the most common in practice and they usually yield the best outcome. Often patients present with multiple maintaining factors to injury which they are completely unaware of in day to day life.

I recently had a female patient who came to see me because she kept getting a left calf muscle strain and could only manage a 3km run however she had been comfortable running 12km-15km 3 months previous without any problem. During the case history she explained that she had been a lot busier in work since the injury began. On further investigation this meant that she was giving 2-3 presentations per week whereas before she was doing 1 and often none. She only wore high heeled shoes when presenting and was now spending an estimated ten times the amount of time per week in heeled shoes. She had some osteopathic treatment and began to minimise the amount of time spent in the heeled shoes by wearing flat shoes to and from the presentation venues and within days the injuries began to subside.

That is a brief synopsis of the mechanism behind maintaining factors to injury and unfortunately not all cases are that straight forward but I hope it highlights the importance of being aware of you lifestyle activities in relation to your injuries.

Tuesday, 16 October 2012

What am I going to discuss?

I am very interested in the mechanism behind how things work and as a runner and triathlete it sometimes gets quite interesting. I have a lot of material that I want to discuss on this blog. This is a brief list of some of the topics I plan to discuss but please feel free to ask any questions or suggest any topics!

-What does it mean when something starts to hurt?

-Nutrition 101. What is a calorie? Is calorie counting useful and where do people go wrong? What happens to carbs, fats and proteins in the body?

-When exercising what's going on with the energy systems? Which one is more efficient and which one is best for fat burning?

-What is pain, why do I get pain and what does it mean? Is all pain an indication to stop training?

-How do I improve CardioVascular fitness? What are the heart rate zones and why are they important?

-Is weight training beneficial for endurance athletes such as runners, cyclists and triathletes? What type of resistance training is beneficial and how often?

-Is it important to eat or refuel while running?

-Good books about running/training which will get you motivated!

-Any questions about any of this stuff are very welcome!