Filetype PDF | Posted on 08 Jan 2023 | 3 years ago
Authentication
digital resources
272x Filetype PDF File size 0.81 MB Source: www.eatrightidaho.org
My clients’ standard complaint
Nutrition —
“Nutrition is my missing link. I’ve got my
Your Missing Link?
training down, but my eating needs help…”
Nancy Clark MS RD CSSD FACSM
Sports Nutrition Services, Boston MA
www.nancyclarkrd.com
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
Focus of this presentation
MISSING LINK #1: Respect for the power of food
on performance (and health)
• Exercise and weight management
• Calories, carbs, protein, fat
• Hydration
“You know, Nancy, too many
• Fueling before, during, and after exercise
athletes show up for training but
• Caffeine, alcohol
don’t show up for meals. They might
• Building a balanced sports diet, vitamin supplements
as well not show up for training.”
BC Hockey Coach
Next session on Engineered Sports Foods will cover:
Protein supplements, energy drinks, sports foods and drinks, sodium
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
Even lean, fit athletes get heart disease….
MISSING LINK #2: Breakfast!
• Brian Maxwell, founder of PowerBar and world class The best energy booster: BREAKFAST
marathoner, died at age 51 of a heart attack
• Improves quality of overall diet
• Andy Palmer, two-time Olympic marathon-trials qualifier
• Prevents the need for sugar fixes
died at age 48 of a heart attack
• Enhances performance
• Ed Sheehan, two-time Olympic marathon-trials qualifier
died at age 47 of a heart attack
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
1
Breakfast: The most important meal of the day
Breakfast: Better than a quick-fix
PC I don’t have time for breakfast. And any ways, I’m not hungry
STUDY: Athletes with low glycogen stores biked hard
in the morning...
for 45 minutes, then sprinted for 15 minutes
C I might eat breakfast at 10 a.m. if food were available...
Trial
Improvements during final sprint
P When I do make time to eat in the morning, I have better
#1. Baseline: No fuel, only water
---
workouts that afternoon—and I don’t get as many headaches…
---Snack five minutes pre-exercise---
A I generally eat breakfast. I just have to plan time...
#2. Sugar (180 cals glucose) + water
+10 %
M I always eat breakfast!!! It boosts my energy, curbs
#3. Candy bar (270 cals) + water
+10 %
evening overeating, and helps me control my weight.
#4. Breakfast 4 hrs before + Candy bar + water
+20 %
(800 cals)
Neufer, Costill J Appl Physiol 62(3): 983, 1987
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
MISSING LINK #3: Knowledge of calorie budget
Estimating calorie needs
Example: 140 pound female athlete
The body needs fuel for–
140 lbs x 10 cal/lb =
1,400 Calories RMR
• Resting metabolic rate
(Wt x 10 cals/lb)
50% RMR =
700 Daily activity
• Daily activities
(±50% RMR)
1 hour cardio =
500 Purposeful exercise
• Purposeful exercise
(400-800 cals/hr)
Total calories =
2,600 To maintain weight
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
MISSING LINK #4: How to lose weight appropriately How to eat and be lean––
• Subtract about 10 - 20% from total calorie needs
• FUEL ADEQUATELY during the day
• Divide calories evenly throughout the day
– Have energy to exercise
– Prevent ravenous hunger and food binges
Example: If an athlete maintains weight on 2,600 calories–
2,600 - 20% (~500 calories) = 2,100 calories/day
• EAT REASONABLY at night
Breakfast
7-8:00 AM
500 calories
– Eat appropriately but do not over-eat.
Where’s the
Lunch
11-12 noon
600
snack…???
– To lose weight: “I’d rather be leaner than eat more...”
Second Lunch 3-4:00 PM
400
Dinner
7-8:00 PM
600
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
2
Exercise ≠ weight loss
What are you doing with the other
non-exercise hours in your day?
TRUTH:
Exercise enhances weight loss if it
The sedentary athlete syndrome….
contributes to a calorie deficit.
TRUTH:
30 minutes of exercise = 300 calories
3 minutes of “rewards”= 300+ calories
Be aware of compensatory changes in daily activity!
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
Marathon training ≠ Weight Loss!
Gender differences: Exercise for weight loss
Among 64 novice runners (55% women) in a 3-month marathon-
training program:
• Men:
High level of physical activity
Range of weight changes: -27.5 lbs to +12 lbs
contributes to a lower % body fat.
11% lost weight (n=7) due to change in eating habits • Women: No relationship between
11% gained weight (6 of the 7 were women)
physical activity and % body fat
78% stayed about the same weight (n=50)
Kennedy, ACSM 2010
Westerterp Int’l J Obesity 1997; 21(3):184
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
Gender differences: exercise and appetite
Exercise + obese women = weight loss
18 Women did 350 cals of low or high intensity exercise
Three trials (19 days each)
Their food intake was monitored for 3 days
1. Sedentary (baseline): maintained energy balance
Conclusion:
2. Light exercise: burned 10% more cals; ate -114 fewer cals
--Hard exercise does not suppress hunger the same way
for women as for men.
3. Moderate ex: burned 25% more cals; ate -370 fewer cals
--Hard exercise increases attractiveness of food for women
No compensation in energy intake
Woo, Pi_Sunyer Am J Clin Nutr 1982; 36:470
Pomerleau, Am J Clin Nutr 2004; 80:1230-6
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
3
The E in Exercise is for Enjoyment
MISSING LINK #5: Adequate carbohydrates
Common belief: “Carbs are fattening”
Exercise = to train, improve athletic performance
= to feel good, relieve stress,
A survey of 425 female collegiate athletes across the US reports—
improve health, build muscles
• The athletes wanted to lose 5 pounds, on average
• 43% felt terrified of becoming overweight
Exercise ≠ punishment for having body fat
≠ motivated by the desire to burn calories
Beals, Manore Int’l J Sports Nutr, 2002
Nancy Clark, MS RD CSSD
Nancy Clark, MS RD CSSD
Carbohydrates = muscle glycogen
24 What kinds of carbs should I eat?
Carbohydrate Diet
20 Carb
16
GLYCOGEN
CONTENT 12
(GM/KG MUSCLE)
8
Protein & Fat Diet
Pro + Fat
4
0
Rest/
hard exercise
5
15
25
35
45 hours
5 days
RECOVERY TIME
Nancy Clark, MS RD CSSD
Bergstrom, 1967
Nancy Clark, MS RD CSSD
Quick & slow carbs
MISSING LINK #6: Wrong amount of dietary fat
24
In theory: • Pre-endurance: Slowly digest carbs (Low GI)
Carbohydrate Diet
20 Carb
• Post-exercise: Quickly digested carbs (High GI)
16
In reality: • The glycemic index of a food varies
GLYCOGEN
—depends on where grown, how processed, etc.
CONTENT 12
(GM/KG MUSCLE)
• Each person has unique glycemic response
8
Protein & Fat Diet
Pro + Fat
—can vary 43% on any given day (Vega-Lopez, 2007)
4
• Athletes should choose well-tolerated carbs
0
Rest/
hard exercise
5
15
25
35
45 hours
5 days
Donaldson “Glycemic Index and Endurance Performance”
RECOVERY TIME
Nancy Clark, MS RD CSSD
Int’l J Sports Nutr 20(2)154-165, 2010
Nancy Clark, MS RD CSSD
Bergstrom, 1967
4
no reviews yet
Please Login to review.
