Nutrition in Exercise

A couple of months ago I did a post on how the body makes energy which is a bit of a prelude to this post on how you should fuel yourself when you work out. This is a bit of a generalised view on nutrition as it can vary from sport to sport as you may find that you have different needs, but as a rough guide it is fairly thorough!

Smoothies are a great Pre exercise snack

App Review - Strava

Back in November I posted a review of the Nike+ running app, this was purely because it was the only running app I'd ever really used. I'm a little older and a little more experienced now and I'm glad to say I've seen more of the world and some more apps that are knocking around. Strangely I didn't come across Strava by deciding to go for a run and try something different or because I was having a look through the app store on my iPhone. 

Smoothies - A Power Meal

         Anyone who reads my food plans will know that I drink a lot of smoothies, In my opinion they are the easiest and the quickest way to get lots of healthy things into you in one go. As far as sports nutrition goes they are ideal as well, not only do they get healthy foods into you but they also offer a great option for hydration. As well as all this they are quick and easy to prepare and most of them can be made in bulk and frozen to be drank at a later date. They can be drank as a meal replacement or as a snack just to help you through the day!

What Goes into a Smoothie?

         Almost anything. If you can blend it and its edible then it can go into a smoothie. The majority of smoothies out there will contain milk, yoghurt and some form of fruit, though not all of them do! The trick with smoothies is to find out how to get a good balance of thickness taste and nutritional benefit. Too thick or thin and you wont want to finish it and you'll miss out on some goodness, or if you don't put enough good stuff in then you will end up doing more damage then good!

Nutritious and Delicious!

         I've found that adding things like yoghurt, Ice and banana's will help to thicken the mixture giving it a nice texture and also helping to satisfy your hunger. You can add some nutrients to the mixture by adding berries and other fruits, which as well as being good for you also help give your smoothies a sweet flavour. On top of berries and fruits you can add honey, peanut butter and flavoured whey powder to add some extra flavour and a bit of protein!

What do I need to make one?

         The only thing you need is a blender, and if you can't get a proper one then you can pick up a hand blender from the value section of any supermarket chain for about £5 but you will just make a bit more of a mess and need to put a bit more work into it! Apart from that all you need to make a smoothie is the ingredients your going to put in!

My hard working blender!

Where can I find recipes?

         You don't need to, I find the best thing to do is experiment with different flavours until you find a nice balance of healthy and tasty. However if your in a hurry and want some recipes straight away you can go to the Men's Health website where they have a smoothie maker section full of recipes tailored to different situations. They also do an App for iPhone that does basically the same thing as the website. On top of that there are various food websites out there that have smoothies sections and if you look in the recommended reading section then you will see a book called 'the new abs diet' that is a huge advocate of smoothies in lowering body fat and promoting fitness!

         At least twice a week I make a Blueberry and Banana smoothie as I've found that its perfect for my training, It always leave me full (without being bloated) and full of energy, since I've started drinking them a couple of hours before a workout (with a power bar) I've felt full of energy and my fitness has benefited from this! The recipe is as follows:

• 100g of Blueberries
• 1 medium Banana
• 3 tablespoons of ready oats
• 3 tablespoons of natural yoghurt / vanilla yoghurt
• 1 tablespoon of unsweetened honey
• 1 scoop (30g) of strawberry whey protein
• 300ml of skimmed milk

         I've talked about the health benefits of blueberries in one of my first posts, so they're an obvious choice for my smoothies as they have no real drawbacks but price. Bananas are delicious, full of Potassium and help thicken the mixture as well as being a source of sugar. The oats are a great source of slow release energy and also thicken then mixture, with the help from the yoghurt and banana! The honey gives it a sweetness kick while being a source of sugar in a natural form to give you immediate energy. The strawberry whey protein ads some protein which helps with carb uptake and also adds to the diet quickly and easily. Finally the milk helps add to the volume and dilutes the mixture so if its too thick for your liking you can always add some more! This is my standard but depending on what I can get a hold of and what is in season I do change it up, I sometimes ad strawberries or raspberries instead of blueberries just to give it a different taste!

         If you can't even be bothered to make them then you can always buy them from the shops and there are some really good brands out there!

Innocent have a tasty but expensive range!

Any drawbacks?

         Not really, though obviously its important to remember what goes in must come out, and too much liquid or fibre before exercise is not ideal as you would like to avoid having an accident mid sprint, so maybe be careful with the amount of fruit you add! Its also important to consider what you put in when you think about freezing them for a latter date! Anything with banana in cannot be kept if you have used milk, this is because a reaction takes place causing the banana to start to turn brown and expire early making it inedible. Some consideration must be taken with adding protein as well as if left in liquid state for too long it can cause bacteria to grow so it should either be drank right away or frozen!

         That's your lot for smoothies, give them a go I can't recommend them enough, just make sure you invest in a good blender as they have many uses above making just smoothies and make the whole process quick and easy!

Cheers,

Rich   

How the Body makes Energy

         As you should be aware, in order to exercise (or just do anything in general) our body needs energy. The big question really is how do we get this energy and what is it produced from? Well if you read my earlier post on A Guide to Nutrients then you would know that we get our energy from carbohydrates, protein and fat, but not in equal measures (carbs and protein produce 4kcal/g where as fat produces 9kcal/g respectively). This is not the full story though, usable energy is created using a molecule called ATP (adenosine triphosphate), but all of these nutrients are involved in different ways to produce this chemical. It is probably worth pointing out that this post is going to be a precursor to one on weight loss through exercise and also another article about pre exercise nutrition! This post is a bit heavy with biology and chemistry but it isn't too complex so don't panic!

So what is ATP?

         ATP is thought of as the energy currency of the body, its used in virtually every process in the body. It is made up of adenosine (an adenine ring and a ribose sugar) and 3 phosphate groups. ATP produces energy by hydrolysing (reacting with water) one of the phosphate groups to form ADP (adenosine diphosphate) and a cleaved phosphate group, releasing energy in the process.

ATP + H₂O → ADP + P_i 

         The amount of energy released is about 7.3kcal/mol (1 mol is equal to 6x10²³ units of a compound) which is a relatively small amount however as the ADP unit can be regenerated back into ATP by using the nutrients in our food, we can keep repeating this reaction, so long as we have energy with which to do the reverse reaction! An interesting fact about ATP is that we have so little of it in our body, on average we only have about 250g, which when you compare the size of us and the amount of energy we have, is only a very small amount.

Adenosine ring (right) with the triphosphate tail (left)

The Energy systems

1. The Phosphagen System 
2. The Glycogen-Lactic Acid system ( or anaerobic glycolyic system)
3. The Aerobic system

         All of these systems are used in tandem when ever you exert any effort on a task, they are also all important in their own rights as the exert energy at different rates and at different energy levels!

The Phosphagen system

         This system uses phosphocreatine to generate ATP to be used in the body. In every muscle you will automatically have a small amount of ATP, this is used up very quickly and needs to be replaced if any more work is to be done. The Phosphagen system is used to quickly replace this ATP by breaking up phosphocreatine using an enzyme called creatine kinase into creatine and a phosphate group plus a bit of energy. The energy is then used to bind the phosphate group to an ADP molecule thus regenerating the ATP molecule needed for energy transport.

Phosphocreatine → P + Creatine + Energy

ADP + P + Energy → ATP

         This process is very rapid and can generate ATP instantly to be used in explosive movements, such as when trying to lift a heavy weight or when sprinting. There is only a small amount of Phosphocreatine available so after 6 seconds or so this system ends and cannot be used again until the creatine is converted back to phosphocreatine which takes time. It is unsurprising then that we can only sprint at full pace for a few seconds as the energy produced cannot match the energy required!

         Many of you will have heard of people taking Creatine supplements and this is the reason why. If you can raise the amount of creatine in your body you theoretically should have more explosive energy and should be able to lift heavier weights for prolonged periods, this however is something I plan to discus in a post about supplements in the future! For the sake of this post though its worth saying that creatine is made naturally within the body using amino acids that are obtained from protein in the diet!

 The Glycogen-Lactic Acid system

         This second system is a longer lasting but a bit less rapid system then the first method and involves the anaerobic breakdown of glucose. As mentioned in the post about nutrients, Carbohydrates are broken down and converted to glycogen for storage. When we need energy they are converted back into glucose and used as a fuel to make ATP. This can be done in 2 different ways, 1 of them using oxygen (aerobic system) and the other without oxygen (anaerobic system). This system focuses on the second one and is important when considering high intensity activity that last for about 1-2 minutes.

         When glucose is broken down as a fuel source when there is no oxygen present it gets converted into pyruvic acid and then to Lactic acid, while at the same time producing 2 molecules of ATP. This process is dependent on 2 things, the amount of glucose available, which is obviously limited, and the amount of Lactic acid produced. Lactic acid is a chemical that is linked with fatigue, and causes the burning sensation you feel when you've done some high intensity workouts. It isn't actually the Lactic Acid that causes this burning sensation but the Hydrogen Ions that are produced with it. Either way if the build up is too large then it will cause muscle damage and stop them from contracting. This means that we can only use this system for a short amount of time, which is why it only really dominates in high paced distances such as 400 / 800 meter running or when doing a set of weights in the gym.

Aerobic Pathways (left) and Anaerobic Pathways (right)

         If using the anaerobic route only lasts a short amount of time, produces a short amount of energy and also causes harm to our body, they why do we do it? The simple answer is the speed at which it occurs, while not as fast as the Phosphagen system, it is still much quicker then the aerobic system so will help us get energy straight away and get the body moving, this would have been essential to our survival when we first walked this earth as if it took a couple of minutes before we had the energy to run away or fight something we wouldn't have survived as a species!

The Aerobic System

         The final system produces by far the most energy but is also by far the slowest method by which ATP is regenerated! It is similar to the anaerobic method in the fact that it converts glycogen to glucose but this time oxygen is present so a different reaction pathway is followed!

         The glucose is again converted to pyruvic acid creating 2 units of ATP but this time it doesn't get turned into lactic acid. Instead the pyruvic acid is used in the pathway called the Krebs cycle which is done in the mitochondria within the cell (they are like the batteries of the cell!) and produce another 36 molecules of ATP brining the total up to 38 units of ATP! As you can see this is a massive increase compared to what was available before! On top of this fat can also be used to make ATP using oxygen and this produces between 80 and 200 units of ATP, it isn't surprising that fat makes more as I mentioned before that it is far more energy rich!

         This process is clearly far more energy rich, with the only major downside being the rate at which it occurs. The question is; why does it take so long to produce energy? There are 2 reasons for this, the first is that large amounts of oxygen is required, which means that the rate at which you breath needs to be increased, which relatively is a slow process, on top of this the reaction pathway is very long so it takes long for the ATP to actually be made!

         As you may have already guessed, this system is more suited for long term 'endurance' events like long distance running  or any even that takes an hour or longer. This gives us a clue as to why you will burn off more fat by jogging then by sprinting. Fat can only be burned off through aerobic activities, and as the concentration of glucose in the muscle and blood decreases the amount of fat used for energy increase. It is important to note however that fat needs carbohydrates to be used as fuel, so don't think that you can just cut out all of your carbs and your will just burn through your fat, this just won't happen!

Photo borrowed from Howstuffworks.com

         That's your lot on energy systems for now, Sorry for all the text I promise the next post will contain more pictures!! If you need any more detail on anything said above let me know!

Cheers,

Rich

References

www.sharecare.com

The Complete Guide to Sports Nutrition - Anita Bean

How stuff works