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Be at Your Best – Have Breakfast!

Touted as ‘the most important meal of the day’, what you eat – or don’t eat – first thing in a morning could make or break your performance. Should you have breakfast? Why? What? How much? Let’s explore…

Breakfast Bites

Break-fast. Your first meal in a morning is literally breaking your fast (i.e. overnight fast whilst sleeping). It is therefore an opportunity to refeed and provide you with energy for the day ahead. You might head straight for the cupboards when you wake up, or you might focus on rushing out the door for school or work. The choices you make in a morning could set the scene for the rest of the day. Eating breakfast containing carbohydrate (CHO) and protein  improved sprint performance in one study (Highton et al., 2013). CHO availability is increased with intake, and we know it is a primary fuel source. Having breakfast has been linked with improved mood and psychological states, as well as reaction time. A high-protein breakfast has shown the ability to improve postprandial responses after a meal like satiety (fullness), satisfaction and pleasant feelings (Boelsma et al., 2010). Better still, if you like a cup of tea or coffee in a morning, caffeine intake has could improve mood and alertness – so could help you feel awake and prepared for the day. Try to keep caffeinated products for the mornings and early afternoons. The half-life (how much time it takes for half the caffeine to pass through the system) is around 6-10 hours, meaning if you have caffeine later in the day, it could still be in your system by bedtime and worsen sleep onset (i.e. it’ll take longer for you to fall into a deep sleep).

Going Without Breakfast

An experienced high-performance (you may say ‘elite’) athlete might perform fasted training to enhance training adaptation (Van Proeyen et al., 2011). For most athletes, skipping meals is not necessary, nor a good idea – particularly if you want to perform at your best. Skipping breakfast will likely do the opposite to eating something; negative mood states, alertness, and the big one – reduced physical performance. In younger populations, skipping breakfast has been associated with decreased academic performance. Research has even shown those who skipped breakfast made worse choices later in the day and overate. The link between breakfast (or no breakfast) and your state for the rest of the day becomes a little clearer.

For training and performance, a breakfast containing carbohydrate (1-1.5 g/kg) and protein (20 g) is a good way to go three to four hours prior to your session. For example, a 60 kg athlete might have 60-90 g carbohydrate from a large bowl of porridge made with milk, with a high-protein yogurt topped with fruit. Sounds delicious! Enjoy your breakfast!

 

References

Boelsma, Brink, Stafleu, & Hendriks. (2010). Measures of postprandial wellness after single intake of two protein–carbohydrate meals. Appetite, 54(3), 456-464.

Highton, J., Twist, C., Lamb, K., & Nicholas, C. (2013). Carbohydrate-protein coingestion improves multiple-sprint running performance. Journal of Sports Sciences, 31(4), 361-369.

Van Proeyen, K., Szlufcik, K., Nielens, H., Ramaekers, M., & Hespel, P. (2011). Beneficial metabolic adaptations due to endurance exercise training in the fasted state. Journal of Applied Physiology, 110(1), 236-245.

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BLOG: Myth-Busting – Protein Timing

If you have some knowledge of exercise nutrition, you’ll know that protein is an important part of it. Whether it’s a protein shake, meal prep, or a home-cooked meal, you may feel that you need to down the shake or scoff your food immediately after finishing your workout. Whilst nutrition soon after exercise is crucial for recovery and adaptation, this article dispels some of the myths.

Post-Exercise Protein – What We Know

Protein ingestion post-exercise stimulates muscle protein synthesis (MPS), and ultimately the growth and repair of tissues. Whey protein is one of the most digestible high-quality proteins available – hence its inclusion in many supplements. It is absorbed quickly, making it a great post-workout choice. A ranking of the bioavailability of proteins (how much can be absorbed) is below. At the top we have whey and casein, closely followed by egg protein, soy, and beef. Ingestion of whey and casein has been shown to increase MPS, with greater effects from whey (Burd et al., 2012).

PDCAAS Protein

Casein is a slow-releasing protein, and can be taken before bed to increase MPS overnight. This can also appear in supplements, or in foods such as milk, cheese, and cottage cheese. Casein makes up around 80% of milk, the other 20% being whey. If you’re parents or grandparents ever told you to drink a glass of warm milk before bed, they may be onto something!

Nonsense, Nuances, and the Unknown

A common misconception is that you must glug your protein shake straight after exercise, as if protein fuses to your muscles, making you bigger and stronger immediately. Not true. Protein ingestion after exercise IS IMPORTANT and can enhance recovery, increase muscle glycogen stores and more – but it’s effect on adaptation post-resistance training is less definitive due to the lack of research asking this question (Ivy and Schoenfeld, 2014). The ‘anabolic window’ – the idea of a period after exercise where MPS is heightened and protein is a ‘must’ – has been somewhat exaggerated. Regular protein intake is key.

Branched chain amino acids (BCAAs) are a popular ingredient. As discussed in a previous article, BCAAs are not made by the body. These are: leucine, isoleucine, and valine. Their inclusion in supplements is often justified by the theory that these essential AAs are tougher to obtain through diet alone and may have more value in promoting MPS. Whilst BCAAs should be ingested, supplements are not necessary – consuming whole proteins through the diet is likely just as beneficial.

Leucine is an amino acid responsible for anabolic signalling in muscle (i.e. muscle building) and is found in many animal meats and other sources. Studies have suggested 3 g supplementation maximises the anabolic response (Norton and Wilson, 2009). Good news if you like meat. If you are vegetarian, soy protein and soybean excellent sources. Vegetarian or not, you can obtain the full spectrum of proteins by eating various sources as part of a balanced diet. See your dietitian about this.

References

Burd, N. et al. (2012). Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men. British Journal of Nutrition, 108 (6), 958-962.

Norton, L. E., & Wilson, G. J. (2009). Optimal protein intake to maximize muscle protein synthesis – examinations of optimal meal protein intake and frequency for athletes. AgroFood industry hi-tech. 20 (2).

Ivy, J. L. and Schoenfeld, B. (2014). The Timing of Postexercise Protein Ingestion Is/Is Not Important. Strength and Conditioning Journal, 36 (6), 51-55.

 

BLOG: Myth-Busting – Eating Fat

It has long been thought avoiding dietary fats is the is a safe option. It has been long exaggerated by the media, also (just like most news and science stories nowadays!). “Eating fat makes you fat!”, “Avoid fat like the plague!”, ”Zero-fat this, Zero-fat that!”. Let’s filter through the facts on fats.

Where It All Started

Research appeared to show low-fat diets were beneficial for health. Fat is calorie (kcal) dense; at 9 kcal per gram. Reducing fat intake may, therefore, serve well for reducing over calorie intake. If you’re aiming to lose weight, this may be a good option, since you must obtain a negative energy balance to do so (energy in LESS THAN energy out; aka energy deficit).

Low-carbohydrate, high fat diets have been associated with health benefits recently, but such diets have impaired performance in endurance athletes. For athletes, carbohydrate remains king!

Fat Helps You Function

Fat is important. They provide us with crucial vitamins – A, D, E, and K – that are fat-soluble (BDA). They NEED fat to be absorbed. There are different kinds of fat; some more beneficial than others.

Unsaturated Fats

There are two kinds of unsaturated fats – monounsaturated and polyunsaturated. Intake of monounsaturated fats, like almonds, peanuts, and olive oil, encourages healthy cholesterol in the blood. Polyunsaturated fats are found in sunflower or rapeseed oil (NHS). These could protect against heart disease amongst other advantages (McArdle, Katch, & Katch, 2014). Omega-3 fats are essential fatty acids. The body cannot make sufficient amounts of these. Oily fish, such as salmon and sardines, and nuts like walnuts and almonds, are good sources of these fats. Omega-3s help prevent blood clotting and have heart-healthy benefits.

Saturated Fats

Threats to our health arise if we eat too many saturated fats. They are, however, part of our diets and play a role in bodily cholesterol production. We need fat and cholesterol for hormonal function and other bodily processes (Lichtenstein et al., 1998). We have two types of cholesterol – low-density lipoprotein (LDL) and high-density lipoprotein (HDL) – the latter is known as ‘good’ cholesterol. HDL sees where there is too much cholesterol and takes it to the liver where we can essentially get rid! High saturated fatty acid intake can increase LDL cholesterol, simultaneously increase your risk of coronary heart disease. One must take caution to not go overboard. As with carbohydrate and protein, if we eat too much fat, this is not used by our body for energy but stored as fat instead, and can build up to high mounts in excess if we’re nor careful. It is very difficult to avoid dietary fat and follow a true ‘zero-fat’ diet, no matter how hard you may have tried. This is not a good idea, anyway!

Trans Fats

Found in hydrogenated vegetable oils, cakes, and biscuits; trans fats raise also raise cholesterol. These have detrimental effects on LDL cholesterol, heart health, and cognition. We shouldn’t have more than 5 g/day (NHS).

Final Word on Fat

Eating too much fat puts you at risk of a caloric SURPLUS (energy in MORE THAN energy out) – causing weight gain. This is a good thing if your goal is healthy weight gain of around 0.5 kg/1 lb per week. If weight maintenance or loss are your aims; probably not so good. Sufficient intake of dietary fat is healthy – whether you’re aiming for energy MAINTENANCE (energy in = energy out), a DEFICIT, or SURPLUS.

If you‘ve looked at the recommendations and/or calculated how much carbohydrate and protein you require; the rest should come from fat. When buying foods, the ‘traffic light system’ is a good estimate of how much fat is in the food:

Fat – HIGH = 17.5 g/100 g; LOW = < 3 g/100 g

Saturated Fat – HIGH = 5 g/100 g; LOW = < 1.5 g/100 g

 

References

https://www.bda.uk.com/foodfacts/FatFacts.pdf

http://www.nhs.uk/Livewell/Goodfood/Pages/Fat.aspx

Lichtenstein, A. et al. (1998). Dietary Fat Consumption and Health. Nutrition Reviews, 56(5), 3-19.

McArdle, W., Katch, F., & Katch, Victor L. (2014). Exercise physiology: Nutrition, energy and human performance (Eighth edition; International ed.).

BLOG: Myth-Busting: Carbohydrate Loading

The ingestion and oxidation of carbohydrate (CHO) for maximum performance potential is well-established. High-CHO foods include pasta, rice, and bread. Research has shown a high-CHO diet improves performance. This leads many to scoff their faces; but it is no excuse to go overboard. Do this and you may suffer the consequences.

Carbohydrate for Performance

Carbohydrate, like fat, is used as a substrate for oxidation during exercise. You may know this as what we ‘burn’. CHO is the predominant fuel source in the ATP-PC system (5-30 seconds) and the short-term glycolytic (STG) system ( 60 s to three-minutes) (McArdle, Katch, & Katch, 2014). These systems involve more anaerobic activity – short, sharp bursts as in powerlifting or 100 m sprint (ATP-PC) or a 400 m sprint or 100 m swim (STG). Muscle glycogen stored in your liver and muscle is used when exercising, as well as any fast-digesting CHO you eat or drink during (i.e. your CHO food or drink contains glucose that is readily available for use). CHO ingestion improves performance in endurance sports, and CHO availability increases with CHO intake before, during, and after exercise (Burke et al., 2011).

Carbohydrate Loading

Carbohydrate loading involves eating a high-CHO diet in the run-up to an event or competition; usually around a week before. The idea is that you’ll ‘top up’ your muscle glycogen stores, maximising them if done correctly. The desired adaptation is known as supercompensation (McArdle, Katch, & Katch, 2014). This only happens if you significantly reduce the muscle glycogen stores through prolonged exercise. For the next few days, the athlete follows a low-CHO diet to keep their glycogen stores low, before switching to a high-CHO diet for three days prior to competition. Supercompensation only happens in the muscles which glycogen stores you have depleted. If you were a swimmer you would swim to deplete stores; not cycle!

Now we know the physiology and thinking behind it; let’s summarise. CHO loading isn’t simply devouring every sugary sweet or calorie-dense cake you can find. High carbohydrate intake could lead to gastrointestinal issues (de Oliveira, Burini, and Jeukendrup A ,2014) dependent on many factors such as the intestine. Conversely, undereating dampens your performance potential due to the reduced energy availability for exercise.

Carbohydrate recommendations have been discussed in a previous article, and can be seen below. Note the differentiation from light to very high activity levels, with examples, and CHO targets. A good example is concurrent training – performing strength and endurance training. Here, a low-CHO diet would be < 0.5 g/kg/bw, medium 0.5-1 g/kg/bw, and high > 1-1.5 g/kg/bw per meal based on six meals – as seen in the infographic. This works out as daily intakes of:

Low-CHO – < 3 g/kg/bw

Medium-CHO – 3-5 g/kg/bw

High-CHO – 5-9 g/kg/bw

concurrent training nutrition graphic.jpg

Infographic example of periodised nutrition for concurrent training (Scott Robinson, PhD, and Daniel Owens, PhD).

To summarise, carbohydrate loading is no excuse to overeat and this could have negative consequences if you do so. Instead, it is a strategy that is relative and individual the athlete, and they should tailor it to suit. Carbohydrates are important for exercise, so find what works for you and nail your performance!

References

McArdle, W., Katch, F., & Katch, Victor L. (2014). Exercise physiology: Nutrition, energy and human performance (Eighth edition; International ed.).

Scott Robinson, PhD, and Daniel Owens, PhD.

Burke, L. et al. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29, 17-27.

de Oliveira EP, Burini RC, and Jeukendrup A (2014). Gastrointestinal complaints during exercise: prevalence, etiology, and nutritional recommendations. Sports Med, 79–85.

BLOG: Going for Green – Getting Your 5-A-Day

A common misconception is that eating just two or three of your recommended five-a-day in the UK is acceptable because you’re almost there. Right? False!

WHO Says 5 A Day?

The World Health Organization published a report on a study group of diet, nutrition, and the prevention of chronic diseases (WHO, 1990). This specified upper and lower limits for nutrient intakes, as well as addressing activity levels, lifestyle, and health. The lower limit suggested for fruit and vegetables was 400 g/day; set judgementally rather than from specific evidence. One portion of fruit and veg is 80 g, hence 400 g equals your 5 A Day. There is no upper limit for fruit and veg intake. Your 5 A Day is a minimum. If you can get more – why not!? Higher fruit, vegetable, and legume intake (375 g-500 g) has been associated with lower risks of non-cardiovascular mortality, total mortality in one study (Miller et al., 2017) and all-cause mortality including cardiovascular in another (Wang et al., 2014).

What Counts as Your 5-A-Day?

Virtually all fruit and vegetables are one of your 5 A Day; be they fresh, canned, or frozen (NHS). Frozen fruit and veg may even retain more of its nutrients as the freezing process helps retain nutritious vitamins and minerals. Getting at least 5 A Day might be easier than you think. Some examples are below:

Fruit:

  • Two small kiwis
  • A medium apple or orange
  • Large slice of pineapple

Vegetables:

  • Two broccoli spears
  • Three heaped tablespoons of veg e.g. carrots or peas
  • Three sticks of celery

If you have canned fruit or veg, go for those with no added sugar or salt. High sugar and salt intakes have been associated with adverse health effects like obesity and high blood pressure. 80 g of beans and pulses (lentils, baked beans, kidney beans etc) count too, although only as one of your 5 A Day, no matter how many portions you have. Despite being rich in fibre, they do not contain as many nutrients as other fruit and veg. Small amounts of dried fruit (30 g, like sultanas and dates) and fruit/veg juices or smoothies (150 ml – a small glass). These should be consumed in small amounts due to the high sugar content that can be harmful to your teeth amongst other dangers (BDA).

5 A Day foods help to bulk out your plate with nutrient-dense, often lower-calorie alternatives to what you may choose currently. and the fibres within can help slow down gastric emptying in the digestive process, increase satiety (‘fullness’), and reducing postprandial blood glucose thanks to their classification as low-glycaemic foods. Known also as ‘blood sugar’, this is the ‘spike’ in blood glucose levels after a meal which triggers an insulin response. Low-GI foods (high-fibre) reduces slows glucose absorption and reduces such responses (McArdle, Katch, and Katch, 2014). High-GI foods, like sugary treats and low-fibre choices, give you more of a blood sugar spike and an excessive release of insulin. A large spike will drop quickly and make you hungry again. You could add vegetables and pulses to stews, fill your plate with more salad, and make healthier swaps by switching sweets to a piece of fruit.

 

 

References

  1. World Health Organization. (1990). Diet, nutrition and the prevention of chronic diseases: Report of a WHO study group (Technical report series; 797). World Health Organization.
  2. Miller, V. et al. (2017). Fruit, vegetable, and legume intake, and cardiovascular disease and deaths in 18 countries (PURE): a prospective cohort study. Lancet. doi: 10.1016/S0140-6736(17)32253-5.
  3. Wang, X. et al. (2014). Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: Systematic review and dose-response meta-analysis of prospective cohort studies. British Medical Journal, 349, 5472.
  4. http://www.nhs.uk/livewell/5aday/pages/5adayhome.aspx
  5. https://www.bda.uk.com/foodfacts/FruitVeg.pdf
  6. McArdle, W., Katch, F., & Katch, Victor L. (2014). Exercise physiology: Nutrition, energy and human performance (Eighth edition; International ed.).

 

BLOG: ABCs of Immuno-nutrition – Potential Strategies to Reduce Infection

A, B, C, D, E, F – Getting to know why and how vitamins aid immunity is worthwhile. Many know that we should get vitamins A, B, C, and so on. But why? How about probiotics? Polyphenols? Emerging research suggests these that are just some nutritional methods might improve immunity. Here is a quick rundown of the ABCs!

ABC Vitamins, Foods and More

Sources of vitamin A include cheese, eggs, and oily fish; to name but a few. Also known as ‘retinol’, it can help improve your sight and skin; as well as immunity. Your body can change a substance called beta-carotene into vitamin A. If you like colourful fruit and vegetables – spinach, carrots, sweet potatoes, mango, apricots – you’re in luck. These are rich in beta-carotene. If you are pregnant, however, avoid having too much vitamin A. It could harm your unborn child. Liver and liver products (e.g. pâté) are high in vitamin A. It is best to avoid these. Consult your GP or midwife on this.

There are many types of beneficial B-vitamins. With immunity in mind, we’ll focus on B6 and B12. Vitamin B6 helps form haemoglobin and allows the body to use and store the energy we eat from carbohydrate and protein foods. Sources include pork, poultry, fish, milk, and vegetables. Vitamin B-12 has similar functions – forming red blood cells, energy release, and maintaining a healthy nervous system. Milk, cheese, salmon, cod, and meat are good sources of this.

Found in plenty of fruit and vegetables, sources of vitamin C include oranges or orange juice, peppers, strawberries, blackcurrants, broccoli, and sprouts. Functions include wound healing and protecting cells, blood vessels, bones, and cartilage (NHS). Finally, vitamin E strengthens our immune system and is found in abundance in nuts and seeds, plant oils (such as olive oil) and wheatgerm seen in cereals.

ABC Supplements and Foods Galore

Adequate carbohydrate (CHO) and protein intake is vital for maintaining immune function. A high-carbohydrate diet with carbohydrate beverage consumption of 30-60 g/hour during intense exercise is associated with lower levels of stress hormones (e.g. cortisol) and inflammatory cytokines (Halson et al., 2004). Post-exercise protein may reduce the negative effects of immune depression, also (Gleeson, 2016).

Vitamin D3 supplementation (1000 IU orally) could reduce the incidence of the common cold and the use of antibiotics (Sa Del Fiol et al., 2015). As our main source of this is sunlight, it might be worth taking a supplement during the winter. Athletes with low levels have shown increased URTI risks and longer-lasting symptoms.

Plant polyphenols, including flavonoids, may boost immune function. Daily supplementation of 1000 mg quercetin (found in capers, lovage leaves, and onions) reduced URTI symptoms in cyclists for two weeks after three days of exhaustive exercise (Nieman et al., 2007). Foods such as apples, citrus fruits, grapes, and green tea contain naturally-occurring polyphenols. High fruit intake has been associated with fewer respiratory illnesses.

Probiotics, commonly known as the ‘gut bacteria’, have shown promise in reducing URTI risk and incidence, as well as gastrointestinal discomfort. Lactobacillus and Bifidobacterium are those for which research exists (Gleeson, 2016).

To support immune-nutrition in athletes, Gleeson (2016) summarises the recommendations as:

  • Energy intake should match energy needs – 50% coming from carbohydrate
  • Ingest 30–60 g of carbohydrate/hour during vigorous training sessions
  • Eat enough protein (1.2–1.6 g/kg/day), with 0.3 g/kg post-exercise
  • Ingest adequate amounts of micronutrients – plenty of fruit and veg, or a multivitamin supplement where necessary

Assess the need, risk, and consequence, and consider taking the following supplements daily:

  • Vitamin D3 (1000 IU), particularly in the winter and when sunlight exposure is limited
  • Probiotics containing at least 10 billion live bacteria
  • Plant polyphenols supplements

 

References

Halson S. L, et al. (2004). Effect of carbohydrate supplementation on performance and carbohydrate oxidation following intensified cycling training. J Appl Physiol; 97: 1245–1253.

Gleeson, M., (2016). Immunological aspects of sport nutrition. Immunology and Cell Biology (2016) 94, 117–123. 2016 Australasian Society for Immunology Inc.

http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Vitamin-A.aspx

Sa Del Fiol, F., et al. (2015). Vitamin D and respiratory infections. J Infect Dev Ctries; 9: 355–361.

Nieman D. C, et al. (2007). Quercetin reduces illness but not immune perturbations after intensive exercise. Med Sci Sports Exerc 2007; 39: 1561–1569

BLOG: Immunity – Risky Business

Immunity – Risky Business

As an athlete, it’s good to know you may have a higher risk of infection so that you can address it. A risk of what, though? How? When, why, and where? How can you reduce such chances? This article ticks all those boxes and more!

Infection – The Invisible Villain

Upper respiratory tract infections (URTI) are most common in athletes. Those participating in intense training or endurance events are at higher risk of developing minor URTI symptoms (Gleeson and Williams, 2013; Svensden, 2015). Most know this as the common cold: a viral infection. Symptoms include coughing and sneezing, headaches, a sore throat, and a blocked or runny nose. These often last a week or two. You can catch the virus from an infectious person by touching an object or surface contaminated by infected droplets (such as somebody’s skin) and then touching your mouth, nose or eyes; or inhaling particles with the virus when somebody coughs or sneezes.jeukendrup immune functionProfessor Asker Jeukendrup, Director of http://www.mysportscience.com, illustrates the effect of exercise on the risk or URTIs.

When? Why? Where?

We are particularly vulnerable after vigorous exercise, when white blood cell functions are suppressed, giving viruses and bacteria a window of opportunity to take advantage of (Gleeson, 2016). Lack of sleep, psychological stress, exposure to extreme environments (e.g. very cold temperatures or high-altitude), malnutrition, and even competitions and being around others can increase our risk of developing systems. During intense exercise, the higher breathing rates (lung ventilation) put your lungs at risk of airborne bacteria and your gut may become exposed to bacterial endotoxins; particularly with prolonged heat stress. Air travel to another country has been associated with increased risk of infection, as well as cuts and abrasions on the skin.

Improving Immune Function – Fighting Back

General guidelines to lower the chance of developing immunodepression (Bishop, 2012; Gleeson, 2016 include:

  • Avoid very long training sessions (>2 h), overtraining and chronic fatigue
  • Keep life stresses to a minimum
  • Get enough sleep – quantity (at least 7 h) and quality
  • Avoid rapid weight loss
  • Vaccinate against influenza if competing in the winter

To reduce the potential for transmission of infectious agents:

  • Avoid sick people and large crowds in enclosed spaces if possible
  • Maintain good skin and oral hygiene: wash hands, use antimicrobial gels, brush teeth regularly and use antibacterial mouth rinse
  • Never share drink bottles, cutlery, towels etc
  • Don’t rub your eyes and nose with your hands

If you have developed symptoms already, the BASES expert statement and Ronsen (2005) suggest:

  • Day 1 of illness: Avoid vigorous exercise or competitions when experiencing URTI symptoms like sore throat, coughing, runny or congested nose. Avoid all exercise when experiencing symptoms like muscle/joint pain and headache, fever and generalised feeling of malaise, diarrhoea, or vomiting.
  • Day 2: Avoid exercise if you suffer fever, diarrhoea, vomiting, or increased coughing. If no fever or sickness is present and ‘above the collar’ symptoms re no worse; undertake light exercise (heart rate < 120 beats per minute; bpm) for 30-45 minutes (indoors during winter), by yourself.
  • Day 3: If fever and URTI (or gastrointestinal) symptoms are still present, consult your doctor. If no fever or malaise is present and there is no worsening of initial symptoms; undertake moderate exercise (heart rate < 150 bpm) for 45-60 minutes, preferably indoors and by yourself.
  • Day 4: If symptoms are not relieved, don’t exercise – visit your doctor. If it is first day of improved condition, wait another day without fever and with improvement of URTI or gastrointestinal symptoms before returning to exercise.
  • Cease training and consult your doctor if a new fever occurs or if initial symptoms become worse, coughing persists or breathing problems during exercise occur. Monitor your tolerance to increased exercise intensity. Take another day off if recovery is incomplete.

References

Gleeson, M. and Williams, C. (2013). Intense exercise training and immune function. van Loon LJC, Meeusen R (eds). Limits of Human Endurance, Nestle Nutrition Institute Workshop, 76, 39–50.

Svendsen IS. Factors influencing infection risk in endurance athletes. PhD thesis 2015. Loughborough University: UK

Gleeson, M., (2016). Immunological aspects of sport nutrition. Immunology and Cell Biology (2016) 94, 117–123. 2016 Australasian Society for Immunology Inc.

Bishop, Nicolette C. (2012). Overcoming microbial hurdles: Keeping the Olympics infection-free. Future Microbiology, 7(8), 913-5.

Walsh NP, Gleeson M, Shephard RJ, Gleeson M, Woods JA, Bishop NC et al. (2011). Position statement part one: immune function and exercise. Exerc Immunol Rev, 17, 6–63.

Ronsen, O. (2005). Prevention and management of respiratory tract infections in athletes. New Studies in Athletics, 20, 49-56.

http://www.mysportscience.com

BLOG: Nutrition for Injury and Illness

Exercise-induced muscle injuries are common in all athletes; from recreational to high-performance. Taking care of your nutrition will help your body take care of itself; potentially with faster recovery.

DO’S AND DON’TS

DO: KEEP A WELL-BALANCED DIET – To avoid deficiencies; be they macronutrients (carbohydrate, protein, fat) or micronutrients (e.g. iron, vitamin D). This might sound simple and repetitive, yet it is the foundation on which your dietary quality and chances of recovery lies. Iron is the most commonly reported deficiency – read more in the previous article. Calcium and vitamin D are vital for skeletal development. Calcium is important for bone growth, and vitamin D helps calcium absorption. Don’t forget macronutrients – carbohydrate, protein, and fat. Getting sufficient, high-quality amounts of everything will help you recover again, and again. This includes your ‘five-a-day’ (why not aim for more!?), various lean protein sources, and polyunsaturated fatty acids. I could go on forever!

DON’T: RESTRICT YOURSELF – Severe energy restriction slows wound-healing and worsens muscle loss. Maintaining energy balance (i.e., availability) is critical. If you find this difficult – whether you are bed-ridden, have no appetite, or need extra calories to account for tough training – you may feel that carbohydrate and/or protein drinks and fluids come in handy. Inadequate energy intake can delay growth and maturation, and, for females, cause amenorrhea and decreased bone density (associated with a higher risk of bone fractures!). All this should be done with your energy availability in mind.

Remember: Energy Availability = Energy Intake – Energy Expenditure.

If you’re injured or unwell, and not training or exercising, your energy expenditure will likely be lower and thus your energy intake should match it. This does not mean the quality of your diet should suffer!

DO: EAT ENOUGH PROTEIN –As well as promoting muscle protein synthesis and maximising the training response, protein is vital for adolescents as more is needed to account for growth and development. Inadequate intake impairs your ability to heal wounds and increases inflammation. Conversely, eating enough protein improves wound-healing and reduces inflammation. Higher intakes (2-2.5 g/kg/body mass) may be beneficial, not forgetting regular intake e.g. 20-40 g every 3-4 hours in adults (Tipton, 2015). Leucine, an amino acid found in lots of animal meats, may be beneficial for this. Try to plan your meals accordingly, with a good source of protein on your plate; always. If you’re a vegetarian or vegan, aim for adequate protein from various sources. Seek qualified help if you find this tricky. As there are no adolescent-specific protein guidelines, the best advice would be to follow adult guidelines (as summarised in a previous article).

DON’T: FORGET TO DRINK – Compared to adults, children and adolescents have been shown to have a higher cost of locomotion (they use more energy for movement) and less efficient thermoregulation (Meyer, O’Connor, and Shirreffs, 2007). This means your body finds it harder to maintain homeostasis and keep a good balance of all the bodily processes that come with stress e.g. heat stress and maintaining body temperature. Familiarise yourself with the hydration guidelines and follow them, even though – again – they focus on adults. When necessary, start exercise euhydrated (sufficiently hydrated), monitor and maintain hydration status throughout, and replace the water and electrolytes (such as sodium – more commonly known as salt), lost through sweat and urine, post-exercise. If possible, weigh yourself before and after exercise to see how much body mass you have lost, partly through dehydration, and drink to suit! If exercising for over an hour, consider adding a source of carbohydrate and sodium as part of your hydration strategy. This might be a sports drink, or a ‘DIY’ approach with some fruit juice and a pinch of salt, to taste. Minimise the risk of dental erosion and poor dental health by: drinking through a straw or squeeze bottle (Milesovic, 1997), rinsing your mouth with water after consumption, or even having sugar-free chewing gum (Sank, 1999).

As always, this is on an individual basis. Assess the need, assess the risk, and assess the consequences!

 

 

 

References

Milesovic, A. (1997). Sports drinks hazard to teeth. British Journal of Sports Medicine, 31, 28 – 30.

Sank, L. (1999). Dental nutrition. Nutrition Issues Abstracts, 19, 1–2.

Meyer, F., O’Connor, H., & Shirreffs, S M., (2007). Nutrition for the young athlete, Journal of Sports Sciences, 25:S1, S73-S82, DOI: 10.1080/02640410701607338

Tipton, K. (2015). Nutritional Support for Exercise-Induced Injuries. Sports Medicine, 45 (Supplement 1), 93-104.

BLOG: Don’t Forget the Iron-In!

Iron is a constituent of haemoglobin (in red blood cells) and myoglobin. These transport oxygen around the body, storing it in muscles and tissues, as well as playing a role in energy metabolism. Dietary iron comes in the form of haem (meat mostly coming from meat) or non-haem (fish, eggs, cereals, vegetables). As with any nutrient, iron must be absorbed by the body. Haem is 2-6 times more available for absorption from our diet than non-haem iron (SACN, 2011).

Key Terms:

Iron Deficiency Anaemia – Anaemia caused by an inadequate supply of iron for blood cell anaemia production.

Anaemia – Abnormally low haemoglobin concentrations in the blood. Anything below threshold could mean you have mild, moderate, or severe anaemia. The World Health Organization (WHO) thresholds for anaemia are:

  • 120 g/L for children 12–14 years and non-pregnant females over 15 years.
  • 130 g/L for males over 15 years.

Importance of Iron

Iron is involved in red blood cell production and fighting infections. Iron deficiency anaemia can cause muscle weakness, fatigue, and tiredness. More reasons to eat your iron, man! Since iron is involved in oxygen transportation, its significance for exercise performance is clear. Skeletal muscle contains 10-15% of the body’s iron. This is mainly found in oxidative, slow-twitch fibres that endurance athletes typically have more of (Buratti et al., 2015). Distance runners are at risk due to foot-strike hemolysis (red blood cell destruction), or those who donate blood (Thomas, Erdman, and Burke, 2016).

Iron Deficiency Anaemia

We can suffer from iron deficiency anaemia due to inadequate dietary intake and availability, an underlying inability to absorb it – even blood loss. A ‘warning sign’ is low haemoglobin levels. This is associated with impaired physical work capacity and cognitive development. Conversely, acute (short-term) high intakes can damage the intestinal lining (SACN). In extreme cases, such as taking iron supplements alongside high dietary intake, acute iron toxicity can occur. Nausea and vomiting are just some of the side effects (NHS). Before deciding to take a supplement, consult your GP or registered dietitian. Very high doses can be fatal; particularly to children.

Requirements

Females, adolescents, and athletes need more iron. Recommendations from the Department for Health (1991) for those aged 19-50 are:

  • 14.8 mg (milligrams) for women
  • 8.7 mg for men.

Adolescents need more iron as they undergo pubertal growth spurts and haemoglobin and lean tissue synthesis, and have higher blood volumes (SACN). Such changes are less for females because of lower growth velocities and differences in body composition. Nonetheless, girls require additional iron (up to 70% more according to the ACSM) to account for losses during menstruation as well as growth. Overall, at this age the body uses more iron due to the increased growth rates, meaning there is an increased risk of deficiency in adolescents. Recommended intakes are summarised in Table 1.

Dietary Sources

Iron-rich foods include liver, beef, lentils, chickpeas, and fortified cereals such as Bran Flakes (NHS – University Hospital Southampton). Eat them at the same time as foods rich in vitamin-C (plenty of fruits!) to maximise absorption and try not to have tea, coffee, or high-calcium foods. Research shows these obstruct iron absorption. The haem iron in meat and fish is fairly well-absorbed (20-30%). This enhances non-haem iron absorption if you eat a source of this at the same time, too. Food pairings for iron and vitamin C might include spinach and red peppers, broccoli and tomatoes, or lentils and sprouts. See what you like and mix it up!

Table 1. Iron recommendation for different populations (Department for Health, 1991; SACN, 2011

iron recommendations.png

 

References

SACN Iron and Health Report (2011). Public Health England. SACN: reports and position statements. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/339309/SACN_Iron_and_Health_Report.pdf

http://www.who.int/vmnis/indicators/haemoglobin.pdf

Buratti, P. et al. (2015). Recent Advances in Iron Metabolism: Relevance for Health, Exercise, and Performance. Medicine & Science in Sports & Exercise, 47 (8), 1596-1604.

Thomas, T., Erdman, K., and Burke, L. (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and science in sports and exercise, 48 (3), 543-68.

http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Iron.aspx

Department of Health (1991). Dietary Reference Values for Food, Energy and Nutrients in the United Kingdom. Report on Health and Social Subjects, 41. London: HSMO.

http://www.uhs.nhs.uk/Media/Controlleddocuments/Patientinformation/Digestionandurinaryhealth/Adviceforimprovingyourironintake-patientinformation.pdf

BLOG: Summer of a Sports Science Student

The stereotypical student might head off to Zante for two weeks immediately after their last summer lecture, soak up the sun, and chill out. Downtime is a necessity, so why shouldn’t we all chill out every now and then? This is, of course, on the far end of the stereotype spectrum, and many will have a job, stay proactive, and still integrate social life. So, what does a second-year Sport and Exercise Science student get up to over the summer?

My immediate thoughts after my last exam in May were: “What do I do now!?”. I had no work obligations, no studying, no holidays planned. Safe to say I did not simply leave it be. I wanted – and always have – to be proactive in my approach to life. A perfectionist, somewhat; I’ll admit.

I set about applying for appropriate jobs wherever and whenever I could. If I had one piece of advice for any student, it would be this: practice makes persistent. I’ve lost count of the number of rejections I have had. Yet still, the sweet taste of a single acceptance is more satisfying than any rejection or ignorance. I have indeed been successful on a few occasions and have ultimately kept myself busy, always striving to prove to myself and others that I am perfectly capable to carry out the task at hand. I’ll give a quick overview of my opportunities.

HIIT and Music Research

Early this summer I was approached by Dr Leighton Jones, Lecturer in Exercise Psychology and Lead Researcher for a project involving the popular training method high-intensity interval training (HIIT). I now lead and assist the data collection procedures for this. More details can be found below in the simple graphic I created! Upon the birth of this collaboration, I set out to get as much experience in the labs as possible. I attribute my abilities to Alan Ruddock, chartered Sports Scientist, for his help with this. You my have spotted myself and Alan plastering this all over Instagram. I would be surprised if that were to be the last time we did.

NEW HEADPHONES HIIT

Dissertation

Having received a couple of emails on tips to decide the topic for our dissertation, I made it a priority to do so quickly. I didn’t want to be indecisive. My helping nature means I always want to say “yes” to an opportunity. This year, I learned this simply cannot be the case, and it does not make you a bad person. So I set about prioritising my tasks now. Back to the dissertation and, after reading the BASES (British Association of Sport and Exercise Science) magazine towards the end of 2016, I discovered the area of antioxidants and their effects on exercise. I took the initiative to email Dr Mayur Ranchordas (fairly daunting the first time around, but I had nothing to worry about – lecturers are people too!). Dr Ranchordas has kindly met with me two or three times this summer and listen to me get ahead of myself on all the brilliant research I had read and how much this interested me. With my feet more firmly (ish) on the ground, and without giving too much away, I recently made the final decision on my dissertation title and have begun writing my research and ethics proposals. I’m into thousand-word territory, so am content at the moment! My motivation strengthened by the news that I got a good first for the second year running!

Placement with British Diving

This February, I had the opportunity of a lifetime with British Diving – a six-week placement in Performance Nutrition. I gained positive feedback and have had multiple meetings and email exchanges since to discuss how I can help further. I’ve met some incredible divers, coaches, and support personnel along the way and cannot wait to get back into full swing.

Work, Work, Work!

Success finally came not long ago and I now have two jobs. Both in the sports events industry, one with a bit of catering included. Valuable experience, great colleagues who recognise the flexibility (and sometimes inflexibility) of a student, and a little bit of pocket money to help me pay for things like trips out and going to see the family, BASES conferences, and the ISAK skinfold/body composition course I passed in June! I am currently on the lookout for people to profile, so if you’re curious about your body fat percentage and more – please do get in touch! Plans are in place to complete my REPS Level 3 Exercise Referral qualification so I am another step closer to becoming a  BASES-accredited sports scientist if I wish. All this without forgetting, of course, the blogging! I set up this page a while back and am overwhelmed by the support. I now write for myself, and help out a company called Youth Sport Nutrition, too. Hence, this is my first post in  while, but I have four articles ready to roll out on the topic of immunity. At least one post per week this August; keep an eye out!

I hope you’ve enjoyed reading this snippet of my summer story. I’ve certainly enjoyed putting my achievements down in writing and see this as a celebration of them – I hope you agree.