sports nutrition for kids & teens leah esplen, msc (bpk) [email protected]
TRANSCRIPT
Why?
Kids and teens are not just smaller adults
They need enough energy and nutrients to sustain growth, development, repair and physical activity
There are periods of rapid growth and development during which needs increase even more
These growth spurts are driven by different mechanisms but the result is the same
Early Growth
Velocity ~ 5-15 cm/yr
Driven by Growth hormone (GH) and Insulin-like growth factor 1 (IGF-1)
Early growth spurt then deceleration
2/3 of children have a growth spurt at age 7-8
Increased growth velocity of legs rather than trunk
Pubescent Growth Driven by sex steroids
Growth spurt results in an acceleration of trunk length growth velocity rather than legs
15% of final height is attained
Girls start and attain PHV 2 years earlier than boys
50-80% of the 1500g of the calcium that is accrued from birth to age 20 is from the 2-4 years of pubertal growth
Early and Pubertal Growth
Bass et al., 1999
Open dots represent average length/height
Closed dots represent bone mineralization
Assessment
Food intake checklists
24-hour food recall
An adequate diet provides enough energy for physical activity and to maintain weight over the short term
Weight gain should occur over the long term but increases in muscle mass and height also need to be taken into consideration.
Education
Familiarize them with Eating Well With Canada’s Food Guide
Allow them to help prepare meals and snacks
Prepare meals and snacks ahead of time
Talk to them about meal and snack timing
Choose one adventurous meal a week
Canada’s Guide to Healthy Eating
Meeting Nutritional Needs: Energy for Boys
3-8 years Estimated Energy Requirement (EER)=
88.5 – (61.9 * age) + Physical Activity Coefficient (PA) * {(26.7 * weight in kg) + (903 * height in m)} + 20
9-18 years EER = 88.5 – (61.9 * age) + Physical
Activity Coefficient (PA) * {(26.7 * weight in kg) + (903 * height in m)} + 25
Meeting Nutritional Needs: Energy for Girls
3 – 8 years: EER = 135.3 – (30.8 * age) + PA {(10 *
weight in kg) + (934 * height in m)} + 20
9 – 18 years: EER = 135.3 – (30.8 * age) + PA {(10 *
weight in kg) + (934 * height in m)} + 25
Physical Activity CoefficientsSedentary Typical daily living activities (eg. Household tasks, walking to the bus)
Low ActiveTypical daily living activities PLUS 30-60 minutes of daily moderate activity (eg. Walking at 5-7 km/h)
ActiveTypical daily living activities PLUS at least 60 minutes of daily moderate activity
Very ActiveTypical daily living activities PLUS at least 60 minutes of daily moderate activity PLUS an additional 60 minutes of vigorous activity or 120 minutes of moderate activity
Boys 3-18 y
1.00 1.13 1.26 1.42
Girls 3-18 y
1.00 1.16 1.31 1.56
Meeting Basic Nutritional Needs
Carbohydrate: 45-65% of Energy Intake
Fat: 25-35%› Omega-6 (linoleic): 5-10%› Omega-3 (alpha-linolenic): 0.6-1.2%
Protein: 10-30%
However, this gets a little more complicated when we are dealing with athletes
Meeting Nutritional Needs: Carbohydrate
Girls & boys 9-18 years: › 130g/day (minimum)
Athletes: › 7-10 g/kg/day with more CHO for activities that include
higher intensity and volume.
Fibre› Girls 9-18 years: 26 g/day› Boys 9-13 years: 31 g/day, 14-18 years: 38 g/day
Meeting Nutritional Needs: Carbohydrate
Children & teens rely more on dietary sources of CHO than stored sources.
They also derive more of their energy from fat rather than carbohydrate during moderate intensity exercise and so produce less lactic acid than an adult would, ie. Higher lactate threshold
Children and teens can tolerate short bursts of activity, such as sprints, very well
Meeting Nutritional Needs: Fat
No specific recommendations for overall fat intake but…
Omega-6 (linoleic): › Males 9-13 -> AI = 12 g/day, 14-18 -> 16 g/day› Females 9-13 -> 10 g/day, 14-18 -> 11 g/day
Omega-3 (alpha-linolenic)› Males 9-13 -> 1.2 g/day, 14-18 -> 1.6 g/day› Females 9-13 -> 1.0 g/day, 14-18 -> 1.1 g/day
Meeting Nutritional Needs: Protein
Girls and Boys 9-13: 0.95 g/kg/day Girls and Boys 14-18: 0.85 g/kg/day
Athletes may need up to 1.5 g/kg/day
So far, the dangers of excess protein have been associated with the source of protein. Animal sources of protein typically contain higher amounts of cholesterol and saturated fats.
High protein intake may be dangerous in people who have kidney issues.
Fluid Needs
Girls› 9-13 years -> 2.1 L/day› 14-18 years -> 2.3 L/day
Boys› 9-13 years -> 2.4 L/day› 14-18 years -> 3.3 L/day
Teach them to take a look after urinating, pale is perfect, dark is dangerous
Fluid Needs If urine is dark, continue hydrating until it is pale Rehydrate with plain water unless activity was
continuous for over an hour
Guideline for young athletes: drink periodically until you’re not thirsty anymore, and then another few gulps (Bar-Or, 1995)
<10 yrs =125 mL beyond thirst, >10 yrs = 250 mL beyond thirst
Avoid vitamin waters and energy drinks!
Fluid Needs
Dangers of hypohydration vs. hyponatremia Hypohydration – under-hydration, includes the
classification ‘dehydration’› Functional losses with only 10% dehydration
Hyponatremia – low blood electrolytes (sodium)› Presents very similarly to dehydration but involves
swelling of the nerves – if suspected go immediately to ER and tell them the person was in the water.
Meeting Nutritional Requirements: Micronutrients
Generally speaking, since there is an increase in energy intake there will be a corresponding increase in micronutrient intake so there is no need for a supplement in the absence of disease or disorder
Some specific nutrients to watch for: calcium, iron & zinc
Meeting Nutritional Requirements: Micronutrients Calcium: › Girls and boys 9-18 years -> 1300 mg/day
Iron:› Girls and boys 9-13 years -> 8 mg/day› Girls 14-18 years -> 15 mg/day› Boys 14-18 years -> 11 mg/day
Zinc: › Girls and boys 9-13 years -> 8 mg/day› Girls 14-18 years -> 9 mg/day› Boys 14-18 years -> 11 mg/day
Glycemic Index
Represents the speed in which glucose appears in the blood
High GI -> glucose appears very quickly Low GI -> glucose is slowly released over time
Does NOT represent how much glucose (CHO) is actually in a food
Glycemic Index
Low GI foods are more sustaining whereas high GI foods allow for faster storage of glucose by the tissues (more dramatic insulin response)
The timing and content of pre & post exercise foods is important to an athlete’s performance
Timing & Content for Training
Eat a low GI breakfast 2-4 hours prior to training to help restore liver and muscle glycogen content.
If necessary, eat a medium GI snack in the hour before training.
If training for more than 60 minutes, include small high GI snacks and fluid.
Timing & Content for Training
After strenuous training, eat a snack composed of 1 g of protein for every 4 g of CHO.
Drink fluids as necessary.
Resume a regular meal pattern as soon as possible after training.
Timing & Content for Swim Meets
Eat a low GI snack at least an hour prior to warm-ups to help restore liver and muscle glycogen content.
After warm-ups, eat a low-medium GI breakfast – if event is less than an hour away, eat a medium GI snack and then have a medium-high GI breakfast right after the race.
If a snack is going to be eaten, it should be high GI and be accompanied by water
Timing & Content for Swim Meets
Lunch should be relatively small and eaten right after the last race before lunch time. During meets with a designated lunch break, a larger lunch can be eaten after the last pre-lunch race.
After the last race of the day, snacks with a 1:4 protein: CHO ratio and water should be consumed until parents can get off the deck and a regular meal pattern can be resumed.
Rest and repeat!
Examples of food Low-GI breakfast: fruit smoothie with flax
seeds, spinach and tofu, homemade egg & cheese muffins on whole wheat
Small medium-GI food: trail mix with fruit and candy, half a peanut butter sandwich
High-GI snacks: rice cakes, those delicious gummies from the coaches!
1:4 protein to CHO recovery foods: chocolate milk, smoothie with dairy or dairy substitute base
Female Athlete Triad
www.fasterskier.com
Important References for You Health Canada Website:
http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/index-eng.php#rvm
http://www.swimming.org/swimfit/what-to-eat-during-competitions/
7 signs the young swimmer isn’t eating enough: http://www.usaswimming.org/ViewNewsArticle.aspx?TabId=0&Alias=Rainbow&Lang=en&ItemId=6014&mid=11780
Thank you and have a great season!