FOOD FOR TRAINING, HEALTH AND PERFORMANCE
Let food be your medicine and medicine be your food’ – Hippocrates
Why do we train? Further, do we do everything necessary to maximise our workouts? People train to look good, improve sporting performance or the quality of their life by keeping healthy. Training takes time, organisation and effort; yet people compromise this by an inadequate diet. Here’s how I personally view diet and exercise, bearing in mind this is a very basic overview
Although man has evolved since he left the trees and he started to walk upright; Professor Loren Cordain states that human genes have probably only changed by 0·04% in the last 40,000 years. Basically, we still have hunter gatherer bodies. Dr Barry Sears elaborates further when he describes how our genetic blueprint would have evolved as we were exposed to the natural environment. In this case part of the environment for our primitive ancestors would be the food stuffs that were available to them. Mark Sissons author of the Primal Blueprint also holds the view that what we eat directly affects how our genes function. Eat foods which would be alien to our hunter gatherer forefathers and we’re asking for trouble. With modern ailments like heart disease and cancer being the result.
However, did our forefathers run ultra-marathons, participate in bodybuilding competitions or indulge in sporting events which required complex training schedules? Doubtful. For a start their most likely philosophy was to conserve energy at all costs. No nipping down to the local supermarket for them when food was scarce. It was either hunt or starve. Further, as Prof Cordain points out, man probably would have waited in ambush with his friends to kill a big bison at, hopefully, the first attempt. Rather than have lots and lots of hunting trips chasing small animals. Why? Cordain suggests it would make more survival sense to use the least amount of energy to kill one big 1000lb beast. Instead of using lots of energy trying to kill 1000 x 1lb animals. In fact, you could eventually starve to death by expending more energy to catch smaller game than the energy this game provided. Dr Michael Eades suggests that primitive man probably gorged on foods post-hunt and preserved energy by laying around until he was a hungry enough to need to hunt again
Sports-performers require structured training before performance improves; with the body being adequately fuelled for this training to be effective. So, unlike primitive man, preserving energy just to survive is unlikely to be a priority. But taking on board the correct fuel to help recover from an intense exercise session, and to be fuelled for further sessions, clearly is. Prof Cordain’s research indicates that ingesting white carbohydrates (pasta, grains, potatoes, rice, etc) causes excess levels of insulin release which can eventually lead to diseases like diabetes, heart disease or a stroke. Interestingly, he suggests you can as eat as much protein as you like -or at least until you no longer feel hungry- providing you also eat lots of vegetables and fruits of different colours. This, he suggest, prevents what is described as ‘protein toxicity.’
Johnny Bowden in his book The most Effective Ways on Earth to Boost your Energy makes the point that if you ate food with a high glycaemic loading after just sitting around watching TV. The glucose in the blood from, resulting break down of the chocolate you just ate, would arrive at the muscle cells (delivered by elevated insulin levels from the pancreas) who would refuse entry (like an irate doorman at an exclusive night club dealing with a drunk) because they haven’t been active and therefore they didn’t need the glucose to replenish their glycogen stores, thank you very much. Whereas the fat cells are a bit like salesman at a timeshare presentation they will drag anyone in! Insulin does its job so well in offloading blood glucose into the fat cells that glucose levels in the blood plummet. Then you start to feel irritable and low in energy. Further, after the muscles (working at a relatively high intensity) the brain is the greatest user of blood borne glucose so your mental acuity is affected as well. Ever gone back to the office after a heavy lunch and felt like you want to just go to sleep? Now you know why. Great isn’t it? Now not only are you storing glucose as fat you can’t think straight either; folks Insulin isn’t called the fat storage hormone for no reason. And, as Johnny Bowden observes, as soon as this happens most people reach for a sugar fix to get the blood sugar levels back up. So the vicious cycle recommences –madness! After a while the body’s cells react to the massive swings in insulin levels this creates; with some researchers concluding that these cells become insulin resistant because of this-alongside cellular inflammation which may also be a major contributing factor- consquently we’re heading towards diabetes.
However, what must also be considered is that the working muscles will be screaming out for glucose via broken down carbohydrates (CHO) after a heavy workout. Indeed, research by Mcardle, Katch and Katch in Exercise Physiology: Energy Nutrition and Human Performance state that are two types glucose transporters (GLUTs 1 & 4 ) which are ‘carrier’ proteins that appear on the muscle cell surface to create a mechanism for ‘grabbing’ glucose and storing it as a polymer (a long chain of molecules, in this case glucose) called glycogen within a muscle cell, if they’re not required for immediate use during exercise. GLUT 1s come to the surface mainly post–exercise and are not dependant on insulin. Therefore, glucose can be transported into the muscle cell without increased levels of insulin. Whilst GLUT 4 transporters are mainly insulin dependant and migrates to the muscle cell surface during exercise.
However, there is strong evidence to suggest that as secondary mechanism exists within exercising muscles that drags glucose in via GLUT-4, transportation without the need for insulin. In an excellent review paper by Holloszy, in the July 2005 edition of the Journal of Applied Physiology, describes how there is an increase in GLUT-4 transporters post-exercise, to the muscle cell's surface, which helps to elevate muscle glycogen levels that have become depleted as a result of exercise. Additionally, Holloszy suggests that calcium release due to muscle contraction during exercise is the cause of this increase. So even though an increase in GLUT-4s from the depth of the muscle cell to the cell’s surface has occurred, as a secondary mechanism ( without the need for insulin). Those GLUT-4s take full advantage of any insulin available to transport glucose into the muscle cell post-exercise to be stored as glycogen. Bowden describes this as a ‘welcome sign’ for insulin; because there are more of those transporters available, providing we exercise on a regular basis. Holloszy also suggests that this would make the muscle cells more ‘insulin sensitive’ as less insulin is required due to the increase of GLUT-4s. Which is a bonus if you want avoid wearing out the pancreas by creating surges of insulin to overcome an insulin resistant muscle cell.
So, does it mean after a workout we can indulge in ‘stickies’ occasionally? Well yes and no. Firstly let’s look at the concept of Glycaemic Index (GI) and Glycaemic Loading (GL) and let me give a politician on Question Time answer before I hit the main points. Glycaemic Index is used to describe the rise of blood sugar levels after you consume carbohydrates. Bowden describes how an a 50g portions of various carbohydrates were measured for their effects on blood sugar elevation against a standard of 50 g of pure glucose which gave a maximum blood sugar reading of 100. High GI foods give a reading of 70+ whilst low GI foods measured 40 and below. He indicates that it’s not just the GI index reading we should consider (if you just eat low GI foods you’ll be fine insulin response wise) but the GI loading. For example, he describes how a volume of carrots that contains 50g of carbohydrate would have a high GI. However since one carrot contains only 3g of CHO you’d have to eat loads of carrots to elevate your blood sugar levels. So portion size is going to vary to give 50g of CHO. This is why GI loading is more useful because it actually accounts for the effects of portion size on blood sugar levels. Anita Bean in the Complete Guide to Sports Nutrition makes the point that athletes on multiple daily training sessions would benefit from high GI foods because they would replace glycogen store more quickly than low GI foods and therefore the muscles would be refuelled ready for the next training session. She also suggest that the first 2 hrs post-exercise is the best refuelling time to get glucose into the muscles to be stored as glycogen. With replenishment rates 150% faster than normal; although they continue to be higher than normal up to the first 6 hrs.
So in theory it seems plausible that you could eat a sticky bun post-exercise and as this would be classified as a high GI food. So that’s the good news. However for those who don’t exercise on a regular basis and continue to ingest high GI foods here’s the bad news: an increased chance of Metabolic Syndrome. This is characterised by sufferers having insulin resistance, high blood pressure, upper body obesity, diabetes and a host of other nasties. In particular insulin resistance where the body’s cells are no longer as effective removing glucose from the circulation and thus normalising blood glucose levels. This means that excess glucose attaches to protein molecules and causes blockages in the capillaries, for example the small ones in the eyes and kidneys. Not a good place for your body to be. Obviously, not all high GI foods are created equal. The body needs the necessary vitamins and minerals to function properly with: growth and regeneration of tissues, hormonal balance, energy production from cells and a strong immune system being vital, especially when training hard. So, post-exercise replenishment should maximise increasing muscle glycogen stores with medium to high GI foods that also have a high nutritional value and the necessary dietary fibre to keep you regular. I quite enjoy a mixture of bananas, grapes and sweet apples post exercise. There’s loads of information on high, medium and low GI foods and their nutritional contents. So a little research will quickly allow you to design your own post-workout concoctions. Also be aware that the inclusion of fats in this dietary mix can reduce the GI of foods. So if you’re going to use that strategy ensure it’s healthy fats containing mainly omega 3 fatty acids. Dr Sear’s Zone series of books gives excellent information on this subject, as does his blog.
So do I ever go ‘off message’ and eat foods with empty calories such as cakes and buns? Too right I do, but just occasionally. Overall though, I have a diet where I eat protein with every meal, if possible, lots of vegetables of different colours and a wide variety of foods. I also have small regular glasses of red wine to ensure I maintain robust cardiovascular health (my friends reading this blog can stop that laughing right now!). This is a balance between Dr Sear’s Zone diet and the Paelo diet recommended by Prof Cordain. Small regular meals is key with 3 main meals and small healthy snacks in between. This keeps my insulin, and blood sugar levels, balanced during the day; so I don’t feel hungry because of low blood sugar. Also it helps to ensure that I feel alert and buzzing when I work with my clients as my brain, such as it is, has a steady supply of glucose. My calorie input will vary depending what type of physical training and associated activities I undertake that day. I strongly recommend purchasing Anita Bean’s book as a ball-park guideline for estimating calorie consumption.
Finally, (at last I hear you cry) organic or not organic? Paul Chek in his book How to Eat Move and be Healthy tells it straight: eat organic whenever you can. I mean do you really think ingesting pesticides is a good idea? And please don’t tell me that eating fruits and vegetables treated with pesticides is safe providing you wash them first. Just ask yourself who is giving you that information and why. Whilst, I’m on a quasi-political rant people will also state because the world’s population is growing we have to use pesticides to increase food production. Well here’s a suggestion: stop being indoctrinated into having lots of children you can’t feed properly! We'd have a much healthier and safer world with people not having to fight over limited and increasingly poisoned food sources. Sermon over-go forth train hard and eat healthily.