Monday, May 22, 2017

An Ingrained Truth: Pre-Exercise Fuelling & Post-Exercise Recovery Foods for Performance

By Toni L Franklin

Accredited Practising Dietitian, Dietitians Association of Australia, Provisional Sports Dietitian, Sport Dietitians Australia


The desire to seek out new or peculiar foods to add to our arsenal of table talk, or ‘foodstagram’ posts, is born out of natural human curiosity. But is there any grain of truth in the notion that we should be seeking out exclusive ancient grains to fuel our exercise training and performances?

Fuelling our bodies before exercise and restoring nutrition after exercise is a fundamental component of Sport Nutrition. Why?

Before exercise, the carbohydrate in food tops up our liver and muscle glycogen stores, especially if we are training first thing in the morning after an overnight fast. Eating before exercise also helps to avoid that niggling hungry feeling and help us get the most out of our training. Taking care to eat foods that don’t cause gastrointestinal upset should also be at the forefront of your food choices (1,2). After exercise, food helps you refuel in preparation for subsequent exercise sessions, promotes muscle repair and growth, boosts adaptation that occurs as a result of training and supports your immune function (3,4). The combination of appropriate nutritious foods and exercise works synergistically to help you achieve your goals.

Traditional and ancient grains battle it out on the playing field. Which is best?

Grains are a nutritious source of carbohydrate, fibre and micronutrients. A good comparison of the nutrient composition of different grains is found in the article “What’s all the fuss about trendy grains?” Grains also contain some protein, a fact that is commonly overlooked. Previous studies have investigated animal protein sources with a high amount of an amino acid called leucine and found around 20g stimulates muscle protein synthesis during recovery from exercise. However, we have recently seen an increasing interest in investigating plant sources of protein to support muscle protein synthesis, perhaps through fortification of leucine or by combining plant based proteins such as grains with complementary amino acid profiles (5).

So do both the hipster ancient grains and the traditional grandparent grains provide appropriate fuel for exercise? 

 The answer is yes. However, at this point, it’s important to reveal another essential principle of sports nutrition - using familiar foods with a known tolerance is always encouraged for key training sessions or competition. Most runners would not wear a brand new, untested pair of running shoes for a marathon race unless they are invincible to injury, blisters and indifferent about performance. If an ancient grain buckwheat, quinoa and chia acai bowl is what you normally eat and tolerate before exercise, go forth and conquer. But a good old-fashioned porridge or some whole grain toast with banana and honey is equally effective and possibly more tolerable on the gut if this is what you are used to eating. There is also something to be said about the nostalgic calming effect that familiar foods can have on settling rattled nerves before a big event. The crux of the matter is that a varied diet remains central to a healthy lifestyle. Both traditional and ancient grains should be friends not foes and there is no grain more ‘superior’ than another.

Key points for fuelling and recovery 

- Have your pre-exercise meal 3-4 hours before exercise if you struggle with gastrointestinal discomfort during exercise. This is more crucial for higher intensity weight bearing sports such as footy and running or sports where your stomach will be jostled about, such as gymnastics or boxing. If you are having a smaller snack this can be eaten 1 or 2 hours before the event.

- Good pre-exercise meals or snacks include: eggs and tomato on rye toast, a whole grain sandwich or wrap with some lean protein and salad, wholemeal raisin toast or oats with yoghurt and fruit.

- Try to have some post-exercise recovery nutrition with a combination of carbohydrates and protein as soon as possible after your event.

- Good recovery nutrition meals or snacks include: whole grain crackers and cheese or nut butter, wholemeal pasta and vegetable salad, tabbouleh, wholemeal spaghetti and meatballs, homemade muesli bar with oats or dried fruit and seeds.

And if you’re ever unsure about what’s best for YOU, contact an Accredited Sports Dietitian for your tailored nutrition plan to help you be your best.

Toni Franklin is a Dietitian with a background in clinical and sport nutrition. For more information about how you can use nutrition to improve your sport performance, please contact a member of Sport Dietitians Australia (SDA), Australia’s peak professional body and credible source of sport nutrition information. Visit www.sportsdietitians.com.au for more information.



References

1. SDA Sports Dietitians Australia. Factsheets: Eating & Drinking before exercise. Retrieved from: https://www.sportsdietitians.com.au/factsheets/fuelling-recovery/eating-drinking-sport/

2. Australian Sports Commission (2009). Eating before exercise. Retrieved from: http://www.ausport.gov.au/ais/sports_nutrition/fact_sheets/eating_before_exercise

3. SDA Sports Dietitians Australia. Factsheets: Recovery Nutrition. Retrieved from: https://www.sportsdietitians.com.au/factsheets/fuelling-recovery/recovery-nutrition/

4. Australian Sports Commission (2009). Recovery nutrition. Retrieved from: http://www.ausport.gov.au/ais/sports_nutrition/fact_sheets/recovery_nutrition

5. Witard, O.C., Wardle, S.L., Macnaughton, L.S., Hodgson, A.B., Tipton, K.D. (2016). Protein considerations for optimising skeletal muscle mass in healthy young and older adults. Nutrients, 23;8(181) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848650/

Carbohydrates & Fertility: An Update On the Latest Research

By Melanie McGrice, AdvAPD

One in six Australian couples struggle to conceive [i] and the psychological, physical and emotional impacts of infertility can be overwhelming.  As one woman struggling with fertility recently wrote on her Instagram feed “I am angry.  Angry at my friends and family who managed to have children easily, angry at the doctor who told me that I had nothing to worry about, and mostly, angry at myself for all of the croissants that I’ve eaten over the years.” 

Pre-conception weight is one of the major risk factors for fertility outcomes and it is well accepted that weight loss improves fertility in overweight and obese women [ii]. In fact, research suggests that women who have a body mass index (BMI) greater than 30kg/m2 often have natural menstrual cycle disruptions at a rate of almost three times higher than women of a healthy weight [ii]

Although research shows that low carbohydrate diets are no better for long term weight loss than other energy restricted diets (and in fact, may be worse as they are often more difficult to ensure nutritional integrity, and are often more difficult to maintain), low carbohydrate diets are a popular choice for rapid weight loss [iii].  Considering the urgent weight loss requirements for many women (particularly in their late 30’s and early 40’s) wanting to conceive, we wanted to investigate the impact of low carbohydrate diets for conception.

Overall, the research shows that lower carbohydrate diets have a positive effect on reproductive hormones, ovulation rates and pregnancy rates than standard diets in women who are overweight or obese. However, before adopting a low carbohydrate diet there’s a few important factors to keep in mind….

1.      Firstly, the research does not yet confirm how low in carbohydrates the diet should be.  Our research was based on diets which were less than 45% carbohydrates so that we could include Very Low Energy Diet studies (also known as intensive phase meal replacements where all meals are replaced with meal replacements).  However, although lower than usual, 45% carbohydrates is not ketogenic for most people.

2    There’s one small prospective study which used meal replacements (which didn’t meet the criteria for inclusion into our systematic review), that actually reduced the number of eggs available for fertilisation [iv]!  This provides a warning that low carbohydrate diets are not suitable for everyone wanting to optimise their fertility.  One possible alternative may be a low carbohydrate diet for short term weight loss, followed by a period of slight weight regain.  This practice, known as “flushing” is often used to improve the fertility of farm animals [v]. A pattern of a period of weight loss, followed by a period of weight regain has also been found to demonstrate a positive impact on reproduction in women [v].  

      Consequently, I believe that a low carbohydrate diet should only be utilised for a short period of time to optimise menstrual cyclicity and fertility hormones, followed by a period of renourishment.

3.      Furthermore, optimal nutrition is essential in the lead up to pregnancy. Wholegrains are some of the best sources of key fertility nutrients such as iodine and folate.  Women following a low carbohydrate diet without meeting all their nutritional requirements could do more harm than good, so it’s essential to seek expert advice from an Accredited Practising Dietitian when considering a change in diet at any life stage. 

      The takeouts here are that low carbohydrate diets are clearly not suitable for everyone looking to lose weight in order to increase their fertility. However, a low carbohydrate diet may be a suitable option for some women who would benefit from losing weight prior to conception. As such it's important to always seek expert advice from a qualified nutrition professional, before embarking on any dietary changes.

To see the review or for further information, go to www.melaniemcgrice.com.au/research

References

[i] http://www.health.gov.au/internet/publications/publishing.nsf/Content/womens-health-policy-toc~womens-health-policy-experiences~womens-health-policy-experiences-reproductive~womens-health-policy-experiences-reproductive-maternal~womens-health-policy-experiences-reproductive-maternal-fert

[ii] Sim, K.A.; Partridge, S.R.; Sainsbury, A. Does weight loss in overweight or obese women improve fertility treatment outcomes? A systematic review. Obes. Rev. 2014, 15, 839–850.

[iii] http://ajcn.nutrition.org/content/90/1/23.short

[iv] Tsagareli, V.; Noakes, M.; Norman, R.J. Effect of a very-low-calorie diet on in vitro fertilization outcomes. Fertil. Steril. 2006, 86, 227–229.

[v] Butler, S.T. Nutritional management to optimize fertility of dairy cows in pasture-based systems. Animal 2014, 8, 15–26.