Nutritional Challenges for High Performance Athletics

Peter W.R. LemonThe University of Western Ontario

Factors Affecting Dietary Needs

• exercise type/intensity/duration• continuous vs intermittent• rest/recovery time between sessions• degree of adaptation (training)• environment• age• gender

Nutrients Known to be Important• energy intake

60

80

100

120

140

160

180

200

Ener

gy In

take

(% o

f se

dent

ary

cont

rol)

Men Women

Activity & Energy Intake

SwimRunBodyBXC-SkiWt liftWresB DanceBasketGym

455

460

465

470

475

2000

m

Erg

omet

er

Tim

e (s

ec)

Performance with/without 940kJ/d Supplement in Elite Female Rowers

Day 0Day 19

Day 0 472.4 463.3Day 19 467 461.4

Protein Fat

P<0.05 d0 vs d19(n=8/treatment)*

* *Bachman, Talyor, Lemon, 2000

*

Lemon, 1998

Nutrients Known to be Important• CHO intake

10

10.25

10.5

10.75

11

Tim

e (m

in)

Time Trial Following 50 min@ 80% Aerobic max, n=8

10.9 10.2Placebo CHO

*P<0.05

Below et al (1995)

6.4% faster

Chronic CHO Intake & Performance

0

50

100

150

200

50 150Muscle Glycogen (mmol/kg)

Tim

e to

Exh

aust

ion

(75%

Aer

obic

Max

)

Bergstrom et al (1967)

Low CHO (5% energy)

High CHO(82% energy)

*P<0.05

Nutrients Known to be Important• fluid intake

Controversial topics

• protein• fat• vitamins/minerals• creatine• variety of others, ie., glutamine, ribose,

HMB, prohormones, ephedrine, caffeine, CLA, etc

• other questions, ie., timing of nutrient relative to training sessions, etc

0

50

100

150

200

250

Whole Body Protein Synthesis (mg/kg/h)

0.9 1.4 2.4

Protein Intake (g/kg/d)

Protein Intake & Protein SynthesisSedentary ControlsStrength Athletes

Tarnopolosky et al (1992)

*P<0.05

Protein?

Post-ex Amino Acids Ingestion increases protein synthesis!

Effects on Strength & Size? - yes

Leg Press Endurance- Reps at 80% of 1-RM

0

10

20

30

40

50

60PrePost

Pre 10.0 7.7 11.9Post 40.0 23.9 29.8

Protein+CR Protein CR

** **P<0.05

mean+SD

*

Creatine and protein may enhancemuscle strength/size gains with training!

Whole Body Lean Mass (kg)

63656769717375777981

PrePost

Pre 68.1 66.4 69.0Post 70.8 67.6 70.7

Protein+CR Protein CR

*

P<0.05*

**

mean+SD

Beneficial for aged, muscle disease, etc?

Challenge(s)?• several– athletes: what product(s) to take?– scientists: provide the objective data to clarify picture• but traditional funding inadequate!

– industry: credibility – regulators: quality control, safety

• solutions ?????– partnership - science and industry (% of sales)– benefits ????• equip more laboratories• unbiased data collection; more speculative research• answers, new product ideas, and enhance credibility/

marketability of products by verifying applicability of theory