Fruit and Veg: The Winning Edge

a lady picking up an apple

This is a guest post by  Bethanie Allanson, Sports Dietitian, Australian Institute of Sport & Benita Lalor, Sports Dietitian, Australian Institute of Sport

Issue: Volume 29 Number 3

The importance of fruit and vegetables in the diet is generally promoted with a public health focus, with an increased intake being associated to a decreased risk of Type 2 diabetes, stroke, cardiovascular disease, hypertension and some forms of cancer.  Many athletes fail to see the significance of incorporating fruit and vegetables into their daily food intake and either ‘leave them on their plate” or forget them altogether.

From an athlete’s perspective, the vitamin and mineral content of fruit and vegetables has an important role to play in maintaining health and well-being and optimising exercise performance during periods of heavy training.  A number of vitamins and minerals provided by fruit and vegetables have a functional role in exercise performance and recovery following strenuous exercise.  These nutrients can not be synthesised by the body so it’s essential that athletes consume a diet rich in fruits and vegetables to support daily training and recovery from training.

While there are no specific recommendations for athletes regarding dietary intake of fruit and vegetables, the population nutrient reference values (NRV’s) are deemed appropriate for use with athletes, due to their wide safety margin.

Fruit and veg and performance

Many athletes would not give much thought to the effect of a sub-optimal intake of fruit and vegetables on their sporting performance.  A decreased intake of the vitamins and minerals found in fruits and vegetables can lead to fatigue, muscle damage and impaired immune function all of which can have detrimental effects on training and recovery for competition (Watson et al. 2005).

The beneficial components of fruit and veg

The accumulative effects of an intensive training program, travel and hectic competition schedule place an athlete at increased risk of illness and infection.  Suppression of immune function in athletes is multifactorial, however it must be acknowledged that several vitamins (vitamin A, vitamin C, vitamin E) and minerals (magnesium) found in fruits and vegetables have a role in maintaining the integrity of the immune system (Gleeson et al 2000).

The transportation of oxygen in the blood to the working muscles is vital for aerobic exercise function.  Haemaglobin is the protein responsible for oxygen transportation and iron is an essential part of this system.  Although the non-haem iron in green, leafy vegetables is not as readily absorbed when compared to the haem iron found in red meat, poultry and seafood, it can be enhanced by the inclusion of a fruit/vegetable source of vitamin C.   These combinations and increased variety of fruits and vegetables is particularly important for vegetarian athletes.

Antioxidants are the body’s mechanism of protection against free radicals – nasties produced in the body.  Production of free radicals is increased during exercise, resulting in oxidative stress and cell damage.  The effects of oxidative stress on sporting performance may include fatigue, muscle damage and reduced immune function (Trent et al).  Studies have demonstrated that dietary sources of antioxidants provide protection against the production of free radicals.  Interestingly, anti-oxidant supplements may not provide the same benefit despite many supplements providing much greater quantities of antioxidants. The antioxidants found in fruit and vegetables play a major role in protecting the body against oxidative stress and subsequent effects on performance (Watson et al 2005).

Are your athletes are at risk?

Athletes who fail to meet recommended intakes of fruit and vegetables are at risk of compromising their performance.  Studies have shown that many athletes consume insufficient amounts of fruit and vegetables (Ziegler et al 1999, Farajian et al 2004).  Athletes at increased risk of sub optimal intakes of the micronutrients found in fruit and vegetables include; athletes who restrict their energy intake (eg. aesthetic and weight making sports), fussy eaters, athletes responsible for their own food preparation and those travelling overseas where availability of fruit and vegetables may be limited.  It has been reported that females and younger children tend to have higher intakes of fruit and vegetables when compared to males and adolescents (Rasmussen et al 2006).

Food or tablet?

While athletes can meet their recommended intake of vitamins and minerals through a nutritious, well chosen diet, many athletes choose to take vitamins and minerals, including antioxidants, in tablet form believing it will give them a sporting edge.

Consumption of large doses of vitamins and minerals, which may be common practise for some athletes, is likely to do more harm than good.  Megadoses may have toxic effects and can be detrimental to performance.  Large doses of individual vitamins, in particular antioxidants are not recommended (Gleeson et al, 2000).  However, there may be situations where the use of supplements is beneficial.  A broad-range multivitamin may be used when athletes restrict their total energy intake for weight loss or weight maintenance, during a heavy competition schedule where there is a disruption to the normal eating patterns, and where availability of food is limited.

Antioxidant supplements may be of use for elite athletes in specific circumstances including an increased training volume or intensity, altitude training or during periods of heat acclimatisation.  These training situations are likely to lead to the increased production of free radicals and supplements may be useful to help reduce the oxidative stress.  It is recommended that athletes considering the use of any vitamin and mineral supplement consult a qualified Sports Dietitian.  See Sports Dietitians Australia website: www.sportsdietitians.com.au to find a Sports Dietitian located near you.

Practical suggestions for athletes to ensure an adequate fruit and vegetable intake:

  • Fruit is a great snack and should be at the top of the snack list. Fruit is a very nutritious source of carbohydrate, so is ideal before or after training to top up fuel stores to assist training performance and recovery.
  • Don’t throw overripe bananas away. They are great in banana cake – see Survival from the Fittest or can be frozen and used in fruit smoothies.
  • If you’re making a lasagne, grate carrot and zucchini into the bolognaise sauce. You don’t even know though they’re there.
  • Baked vegies are often a favourite for most, although they can be high in fat.  Next time, try lightly coating your vegetables with oil with a pastry bush and cook in an oven tray covered with foil.  Remove the foil 10-15 minutes before you finish cooking – this allows the vegies to brown up.
  • Fruit juice doesn’t replace fruit, as much of the fibre is removed. You can’t substitute the value for a whole piece of fruit with juice.
  • Fresh or canned fruit added to cereal at breakfast is a great way to kick start your fruit intake for the day.

Bottom Line

To maximise performance, all athletes should be encouraged to obtain the range of antioxidants and other vitamins and minerals found in fruits and vegetables through their daily food and fluid intake.

Table 1: Nutrients and their sources
Nutrient Performance related function Fruit and vegetable sources
Vitamin A
  • Immune function
  • Antioxidant properties
  • Carrots
  • Pumpkin
  • Mango
  • Apricots
  • Spinach
  • Broccoli
Vitamin B1 (Thiamin)
  • Energy production and supply
  • Nerve function
  • Muscle contraction
  • Legumes
  • Bamboo Shoots
  • Cauliflower
  • Sweet Corn
  • Plums
Vitamin B3 (Niacin)
  • Energy production and supply
  • Nerve function
  • Muscle contraction
  • Peach
  • Nectarines
  • Broad Beans
  • Mushroom

 

Pantothenic acid
  • Energy metabolism
  • Broad beans
  • Broccoli
  • Mushrooms
Vitamin B6 (Pyridoxine)
  • Energy production and supply
  • Nerve function
  • Muscle contraction
  • Brussel sprouts
  • Green peas
  • Beans
  • Split peas
  • Fruit
Folate
  • Nervous function
  • Muscle contraction
  • Haemoglobin synthesis
  • Spinach
  • Broccoli
  • Cabbage
  • Lettuce
  • Beans
  • Beetroot
  • Avocado
  • Banana
  • Orange
Vitamin C (Ascorbic acid)
  • Antioxidant properties
  • Immune function
  • Blackcurrants
  • Orange
  • Grapefruit
  • Guava
  • Kiwi fruit
  • Raspberries
  • Capsicum
  • Broccoli
  • Sprouts
Vitamin E (Tocopherol)
  • Antioxidant properties
  • Immune function
  • Spinach

 

Iron
  • Energy production and supply
  • Haemoglobin synthesis
  • Antioxidant function
  • Broccoli
  • Silverbeet
  • Spinach
  • Chinese green vegetables
  • Dried fruit
  • Sweet corn
Magnesium
  • Energy production and supply
  • Nerve function
  • Muscle contraction

 

  • Green vegetables
  • Legumes
  • Peas
  • Beans

References

Rasmussen, M et al Determinants of fruit and vegetable consumption among children and adolescents: a review of the literature. Part 1: quantitative studies. International Journal of Behaviour Nutrition and Physical Activity,11;3:22, 2006.
Gleeson, M and Bishop, N.C. Elite Athlete Immunology: Importance of Nutrition. International Journal of Sports Medicine; 21 Supplement 1: S 44 – S 50, 2000.
Watson T.A. et al 2005 Oxidative Stress and antioxidants in Athletes Undertaking Regular Exercise Training. International journal of Sport Nutrition and Exercise Metabolism:15, 131-146, 2005
Ziegler, P.J. et al Nutritional and Physiological Status of U.S National Figure Skaters. International Journal of Sport Nutrition, 9, 345-360, 1999
Farajian, P. et al. Dietary Intake and nutritional practices of elite Greek aquatic athletes. International Journal of Sport Nutrition and Exercise Metabolism; 14(5): 574-85, 2004.


The Winning Edge is also the title of an excellent book by Jack Medina. I recommend his excellent article here Whey Protein vs Soy Protein … You Decide!

Like me, Jack is a great fan and long-time proponent of Juice Plus+.