Tuesday, 19 March 2013

Hitting the wall! What does it mean?

I am a firm believer that there is a purpose to every experience in life. No matter how harsh or unfair things seem at the time there is always something to be learned from an experience once you come out the other side.
If you've ever "hit the wall" in an endurance race, you should have learned that you were unprepared and that you made a beginner's mistakes. If it has happened more than once you need to do some research on training and nutrition. And if it's a regular occurrence when you train or race you should seriously think about becoming a couch potato because that's probably a healthier way of living. Let me explain!

The phenomenon of "hitting the wall" happens when you have exhausted the body of its glucose stores to the point where you've bonked and still haven't refueled with carbohydrates. The muscles are relying on the fat stores as an energy source (which is a good thing), but remember fats are very slow burning and the 3 energy systems (see post on bonking) are active all the time. So when the glucose stores are exhausted the easy burning fuel system requires something else to burn. The next easy option fuel source is protein, it's not as easy to break down as carbohydrates but it yields the same amount of energy per calorie, so not a bad substitute.
We never have to worry about our fat stores running low because we are so well equipped at storing fat we can never deplete the stores no mater how far we run or bike. Even elite athletes who race between 3%-4% body fat, it's impossible for them to deplete their fat stores. However in order to keep the fat burning process in operation we need some easy access fuel too. So the body must start to burn proteins in the absence of carbohydrates.

We all know that proteins are what we use to build our bodies. Proteins are an enormously important nutrient and they have far more important functions than building strong muscles. All the hormones in your body are proteins in one form or another, the receptors on cells that receive these hormones are proteins, neurotransmitters (responsible for movement and feelings), immune cells (that fight infection), and inflammatory cells (part of the repair process after training) are all proteins and have a huge role in the body.
When you use protein as a primary fuel source such as when you've "hit the wall" you are jeopardising every system in the body which relies on protein. Some hormones and especially neurotransmitters are very short lived, some have a shelf life of less than a second so our bodies are constructing these proteins all the time with the amino acids (the building blocks of protein) that are stored in our liver. We don't have the capacity to store many amino acids due to their acidity so it won't take long to run low on protein stores too. At which point your body will really begin to fall apart from the inside out. When this happens you will feel like you have run into a wall hence the term " Hitting the wall!"

This can happen for two main reasons; poor preparation and inadequate training or inadequate fuel replenishment on race day as a result of poor nutrition.
The common habits of a novice marathon runner or triathlete is to skip breakfast for fear of stomach cramps during the race. Instead they are backed up with a pocket or bum bag full of energy gels and energy bars. The race begins and so does the sugar roller coaster. If your training has been inadequate for your desired time you won't have the mitochondrial density (power stations for burning fats) to access the energy required from fats, so you over- rely on sugar. Until the sugar runs out! You will feel really sick (or perhaps have been sick) from downing all the gels and the only option for the body is to burn protein. By mile 20 (in a marathon) you'll know all about that wall!
It will probably take 1-3 weeks to recover from this experience and you may get bombarded with a throat or chest infection days after the race as a result of your immune system (defence army) being depleted.
I hit the wall in the first marathon I ever did in 2001 and haven't revisited the experience since. What amazed me most that day was the participants' ability to jog home after the race. I was so beaten up I could hardly stand and here were these guys jogging home after beating me by an hour or more. That's when I knew I had got something wrong,,, very wrong.

Our involuntary (autonomic) nervous system has a sympathetic component (fight or flight) and a parasympathetic component (rest and digest). These two systems work on a see saw motion, if one goes up in activity the other must go down. On race morning the sympathetic system is on over drive which is why you feel nervous, digestion is turned down which is why you feel butterflies in your stomach. It's a good idea to eat a wholesome oatmeal breakfast with some nuts for slow energy release 3-4 hours before the race. It will take a little longer than usual to digest (due to low parasympathetic activity) but you will reap the benefits during the race. After the 45 - 60 minute point of a marathon and after the swim in a triathlon start to refuel with whatever works for you but be advised simple sugars at this point are not the best option. The fuel source should be carbohydrate and slow releasing. Get inventive and find out what works for you. I like sweet potatoes, dates and bananas.
If on race day you are close to your desired time in the final 5km but feeling low on energy by all means crack open the gels and sugar drinks, they will work wonders to get you home, just don't depend on them from an early stage, they will let you down.

Overall preparation, be it mental, physical or nutritional readiness are essential for a race like a marathon or triathlon. The body must be able to endure the mental stress of wanting to quit, the physical battle to carry on and the fluctuating energy levels that occur during endurance sport. If you are not prepared for all three, you are setting yourself up for failure.
Find a training plan that fits into your life, set a goal, stick to the goal and go for it on race day. No matter how good you feel, stick to the plan unless with 5km to go you still feel great; then you can take off and beat the goal. Rehydrate with water at every opportunity and refuel as you need it. Enjoy the experience and remember there is always another race!


Wednesday, 13 March 2013

To Bonk, or how not to Bonk!

There are two slang terms that get thrown around among distance athletes, bonking and hitting the wall. I hear people using these terms and quite often confusing them or mixing them up.

So what happens when you "Bonk" and is it always bad when you Bonk?

When we exercise there are 3 energy systems that we can use to get energy; aerobic system, anaerobic system and phosphagen system (will be discussed in a later post). It's not important to understand those systems completely. It is important to know that each system relies on glycogen as a fuel source, however the reliance on glycogen differs between each system. The aerobic system for example is efficient at using fat too as a fuel source, while the anaerobic system relies on glycogen only and can not use fat as a fuel source. It is also important to know that all systems are in use all of the time when you are running or cycling but again the reliance on each system will vary massively depending on your training set.

As we exercise the glycogen stores become depleted. In the average runner these stores last about 90mins give or take 30mins either side. If you are a real beginner carrying excess weight you might get about 60mins from your glycogen stores, whereas if you have been training consistently for a few years and can hold a good pace while racing you might get 120mins from you glycogen stores. But for the average Joe out there lets say 90mins.

During exercise we are smashing up these glycogen chains (sugars) and oxygen to release energy (ATP) used by our muscles and nerves. The power stations (mitochondria) in out muscle cells can use glycogen and/or fat as a fuel source. However our nerve cells can only use glycogen for fuel. So when our glycogen stores start to get really low our muscles can rely on fat burning and are quite happy to continue. Our nerve cells begin to run low on fuel. Physically we feel quite good at this point but mentally we are a mess. Or to put it in runners terms "Bonking". Our thoughts become confused and we get very agitated, our form will be messy because we lose fine control of our muscles. This poor form requires more energy, plummeting energy stores even further, a negative feedback system for the Bonk.

Bonking means the brain is running out of fuel and is at the early stages of shutting down. Anybody who has fainted during a marathon or triathlon can probably attribute it to the fact that their reticular formation (the part of the brain that keeps you awake) ran out of glycogen.

Bonking is hugely responsible for bike accidents. How often do you hear of some body in your club falling off? I bet if you investigate the crash took place more than one hour into the ride. Bunch sprints in cycling races are notorious for crashes, partly due to the explosion of speed, riders fighting for road space and coupled with the rider in the middle of the action not fully alert due to the BONK!

What all this means is that at about 90mins into a Race you are going to Bonk unless you take measure to combat this. Racing is usually performed in Zone 3 of your heart rate. At this pace you are working aerobically which means the muscles are burning glycogen and fat. The fat burning will delay the bonk by not letting the glycogen stores become completely depleted as quick. However the nervous system is only able to burn glycogen so no matter how fit you are the Bonk is always coming.The more training you do the better you are at getting into the fat burning zone. It is so important to consume some sort of carbohydrate food source if you are exercising over 60mins. Otherwise at some point your form or technique will suffer as a result of an undernourished nervous system.

Note: this blog is not intended to coach or tell you what to do, my goal is to explain this stuff and make it understandable. However I would like to stress that I do not recommend using sports drinks and energy gels to combat the bonk while training. There are other measures that are more ideal which won't screw up your gut or send you on an insulin roller coaster.
Simple carb intake will cause a massive injection of insulin from the pancreas. The insulin will tell every cell (including muscle cells) in the body to burn glycogen and stop burning fat. Within seconds the energy drinks and gels will be utilised and the nervous system will be left wanting. Consumption of a more complex type of carbohydrate snack is always going to have a better effect. It will take longer to break down, so it is a slower release of energy. There is a gradual insulin release from the pancreas and a far better performance from the athlete.

I think it's safe to say that the vast majority of the time it's a bad idea to Bonk. Not only do you become agitated, confused and emotional, your form becomes really poor and the muscle are in a position to start breaking down proteins to fuel movement, which is always a bad idea.
Their may be some benefit to experiencing this once in preparation for a race. If you know what the Bonk feels like from a training experience you can notice the symptoms developing during a race, this can enable you to know when to refuel and what type of fuel you should be taking at a particular point of a race. It's obviously not a good idea to Bonk every time you workout but there can be some benefit to a once off experience.

Recap: bonking is when the nervous system has not got sufficient fuel to perform its tasks and the brain begins to malfunction. 


Tuesday, 5 March 2013

Lactose Intolerance!

I've been an avid exerciser my whole life. I'm fortunate to never have suffered from any serious injury and for the most part exercise has been relatively easy for me. I've spent the last 13 years working as a Physical Therapist and personal fitness trainer and I'm now a practicing Osteopath. All of this has kept me moving and therefore fit and healthy.

Over the past 5 years I've had what I can only describe as "a slight irritable bowel" when running any distance more than 5km. 3-4 years ago when I was marathon training and doing races like Ironman 70.3 UK this problem was more than a slight annoyance. Every time I ran I would get low grade intestinal pain to begin, followed by flatulence and often a need to stop for a toilet break to relieve what is commonly called "Runners Belly", know in another continent as "Dehli Belly".
I was most symptomatic on long runs and interval sessions. I was reluctant to think that I had any control over this, which meant training and racing was business as usual.

For the following 3 years my training was very limited. Myself and my wife became parents to the 2 most wonderful boys. We are both Irish and live in London which, means childcare is always a problem. When both parents run its difficult to commit to the training demands of a long distance race without alienating the other with the chore of childcare at the weekend after a busy working week. My racing was practically nil, however my training was continued albeit at a reduced rate.

Skip forward to November 2012. I signed up to the Paris marathon in early September and my training for the race had started proper. I began as I usually do with 3 weeks base work. Developing my fitness, preparing my body for the journey ahead. This entails reducing body weight; achieved by running all sessions at 65%-72% of maximum heart rate, and increasing local muscular endurance; achieved by plyometric training.

As I began to increase my weekly mileage my intestines became more and more problematic. Until one week, on a planned 22km run I basically had pain from the "Go". After 3.6km I had to stop for a toilet break due to intense intestinal cramp. This pit stop made me feel no better and I reluctantly continued until 8.6km which is when I made my second toilet pit stop. My determination drove me on and I continued with the planned 22km run. At 15km I had to stop again, at this point it I found it almost amusing that I was supposed to be racing in Paris (April 2013).
I eventually threw the towel in at 21 km cutting my run short by 1km but perhaps more disappointing was the dismal time I had accumulated on my failing effort. My (pardon the pun) gut feeling was to pull out of the Paris marathon.  But before I got too hasty I decided to try something different.

At the same time I was reading a book about inflammatory diseases and in particular a neurological condition called "Multiple Sclerosis". The author kept referring to the northern Europe and northern United States as having a pro-inflammatory diet. This phenomenon explains why Caucasians are more prone to certain inflammatory diseases like MS than an African or Asian person whose diet differs somewhat from ours. There are many inflammatory suspects in the western diet but the two obvious culprits are Lactose (a sugar found in dairy products) and gluten (a wheat protein).

Being a long distance runner and cyclist it's safe to say I love my carbs. So the thought of eliminating gluten from my diet seemed as compelling as going to the dentist. So I went with abolition of lactose first. I suppose I had an underlying thought that perhaps lactose was a key player to my symptoms.

When lactose makes its way into our gastrointestinal tract (GIT), it is broken down in the small intestine into glucose which is the sugar form we use in our bodies (see previous post on carbohydrates). The walls of our small intestines release an enzyme called lactase, thus far insulin has not part in this process. Insulin is what we use to tell our cells to burn the glucose that has been produced as a result of breaking down the lactose.
Lactose intolerant individuals do not produce lactase in their small intestine so are unable to assimilate any nutritional good from lactose products. But with an estimated 5% of Caucasians being lactose intolerant, it shouldn't be a major problem right?

With a prolonged intake of lactose such as cows milk (which has about 50% more protein than breast milk) an individual can become sensitive to lactose. This means that the cells in our small intestines can no longer manage the load of lactose that is being consumed. This maybe due to excess intake or loss of the cells that secrete lactase, either way the lactose is not digested.
We have a whole flora of bacteria in our gastrointestinal tract. These minuet microorganism have important roles but if a colony of bacterium grow out of control we will become symptomatic. This is what happens when you become sensitised to lactose.

All living things love sugar. Carbon is the fuel source of life and sugars are simple carbon chains. So when there are undigested lactose products in the GIT the bacteria multiply at rates beyond the norm. All living things produce metabolic waste as a result of metabolism. The metabolic waste produced by these bacterium is methane gas and some other compounds which promote inflammation in a human. Gas bubbles inside the intestines will cause a pressure between the walls resulting in cramps and discomfort. When this gas eventually leaves the tube which is the GIT it is commonly accompanied by a trumpeting sound, a foul odour (methane gas mixed with sour milk among other waste products) and a momentary relief from symptoms.

For the past 3 weeks I have been living off "LactoFree" products. LactoFree dairy produce are available widely across the UK. They have an ingenious way of eliminating lactose, they remove 50%. The remaining 50% is completely broken down by a synthetic lactase enzyme that they add to the milk. The result of all is is a very very slight difference in taste. The difference is so slight that my wife doesn't know if I've put LactoFree milk in her tea or regular milk.
Since using LactoFree milk and butter (that's all the dairy I eat) I have been 98% symptom free. The 2% I'm blaming on chocolate and other products that I eat that contain some lactose. Since the first day I changed to LactoFree products it has felt like somebody flicked a switch to the symptoms in my abdomen .

The plan is to stay LactoFree for a couple of months. This should be time enough to overcome an insensitivity. Then I will reintroduce some lactose products (with a careful eye on my bowels) and see how my body responds.