Nutrition in triathlon
F b February 8 2013 8, 2013, Magglingen M li D S Dr. Samuell Mettler, M ttl Nutritionist, N t iti i t BASPO samuel.mettler@baspo.admin.ch
Topic Competition Preparing for competition Training adaptation
high carb low carb low glycogen train low - compete high
Bundesamt f端r Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Substrate oxidation
glycogen
carboydrates
Blood glucose
fat
Endurance trained athletes (cyclists), (cyclists) fasted Van Loon et al, J Physiol, 2001 Bundesamt f端r Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Preparing for competition Carboloading
1967:
3 day depletion
+ 3 day loading
Astrand et al,, 1967,1968 ,
1981:
normal diet
+ 3 day loading
Sherman et al, 1981
2001:
normal diet
+ 1 day loading
Busseau et al al, 2002
Bundesamt f端r Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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During competition For endurance events of ~2 h (e.g. olympic triathlon) 30-60 g/h
In practice:
swimming: cycling: running:
low ~60 g/h low ACSM Joint Position Stand, MSSE, 2009 Jeukendrup, J Sport Sci, 2011
For endurance events of >3 hours (e.g. Ironman) ‘Older’ ‘Old ’ recommendations d ti
30 60 g/h 30-60 /h ACSM Joint Position Stand, MSSE, 2009
Newer recommendations
up to 90 g/h requires multiple transportable carbohydrates (Glucose + Fructose) Jeukendrup, J Sport Sci, 2011
Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Supplements for triathlon competition Caffeine • «classic protocol»: • «alternative protocol»:
3-6 mg/kg 60-90 min pre start 3-6 mg/kg in multiple doses during event 1-2 mg/kg during exercise
Nitrate? • Potentially useful for short high intensity endurance (~4-20 min) • No evidence for longer events. • Studies with elite athletes: no effect. Ch i t Christensen ett al,l Scand S d J Med M d Sci S i Sport, S t 2012 Peacock et al, MSSE, 2013
Supplementguides: • •
www.antidoping.ch (German) Australian Institute of Sport (English)
Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Question 1: Preparing for competition
Adaptation to increased fat oxidation to… …spare glycogen …improve performance
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EHSM Ressort Leistungssport Samuel Mettler
Question 2: Training adaptation
Is it a lack or a surplus of substrate that triggers training adaptation? H l &B Hawley Burke, k 2010
Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Possible strategies Shortterm high g fat / low carb adaptation p ((e.g. g 1-3 days) y ) Reduced performance
Longer high fat / low carb adaptation (e.g. > 5 days to some weeks) Adaptation possible, possible but no performance benefit
Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Fat adaptation + CHO restoration 5 d high carb
1 d high carb
5 d high fat
1 d high carb
training + diet supervised (495 km / 17 h training) 120 min SS + ~30 30 min TT CHO: 2.0 g/kg 2 h pre-exercise 0.8 g/kg/h during exercise
No performance effect in TT: 25.45 ± 0.67 min (high carb) 25.53 2 3 ± 0.96 0 96 min i (high (hi h fat) f ) Fat oxidation after high fat and still after 1 day high carb Burke et al, MSSE, 2002 Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Fat adaptation + CHO restoration 6 d high carb
1 d high carb
6 d high fat
1 d high carb
240 min SS @ 65% VO2max + 60 min TT CHO: 3.0 g/kg 1 h pre-exercise 100 g/h /h during d i exercise i
non-significant performance improvement
Carey et al, J Appl Physiol, 2001 Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Fat adaptation + CHO restoration 6 d high carb
1 d high carb
6 d high fat
1 d high carb
«100 km cycling TT, including high intensity sprints, simulating race situations» 1 km sprint (5x) 4 km sprint (4x) Haveman et al, J Appl Physiol, 2006 Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Fat adaptation + CHO restoration
Haveman et al, J Appl Physiol, 2006 Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Low carb: adaptations PDH activity
Increased fat metabolism Reduced carbohydrate metabolism Stellingwerff, Am J Physiol Endocrinol Metab, 2006 Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Low glycogen training
100 min steady state @ 70% VO2max 8 x 5 min @ maximal pace (HIT) HIT with normal or low glycogen gy g Cave: low glycogen training ≠ low carbohydrate intake! Trained cyclists (VO2max: 60 ml/kg/min)
Yeo et al, JAP, 2008 Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Low glycogen training
Yeo et al, JAP, 2008 Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Low glycogen training
No effect on time trial performance
Yeo et al, JAP, 2008 Bundesamt f端r Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Low glycogen training
No effect on time trial performance
Hulston et al, JAP, 2008 Bundesamt f端r Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Drawbacks of low glycogen & low carb? •
Increased risk of overlaod / overreaching g Increased training and low carb / low glycogen not at the same time (e.g. training camp)
•
Reduced exercise intensityy + increased RPE Risk of too low self selected exercise intensity
•
Reduction of carbohydrate metabolic pathways Reduced high intensity performance capabilities
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EHSM Ressort Leistungssport Samuel Mettler
Gut adaptation? Adaptation of carbohydrate absorption capacity? Animal models: Intestinal transport adapts to diet. diet SGLT1 + Glut2 «Sweet-Taste-Receptors» p in the g gut Shirazi-Beechey et al, Proc Nutr Soc, 2011 Moran et al, Br J Nutr, 2010 Dyer, Biochem Soc Trans, 2007 Suhr, Am J Physiol, 1997
Oxidation capacity of exogenous carbohydrates also adapts in human athletes. athletes Cox et al, JAP, 2010
Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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Where are we going … ? During competition Optimize carbohydate supply (multiple transportable carbs) Caffeine Preparing for competition Carboloading without fat adaptation for the olympic triathlon Carboloading C b l di with ith previous i f t adaptation fat d t ti for f ironman? i ? Test individual response and tolerance Fat adaptation p g gut adaptation p for high g carb availability? y Low glycogen training or low carb phases? Alternative training stimulus for days / weeks / selected trainings Further data needed...
Bundesamt für Sport BASPO
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EHSM Ressort Leistungssport Samuel Mettler
Topic Competition Preparing for competition Training adaptation
high carb low carb low glycogen train low - compete high
Bundesamt für Sport BASPO EHSM Ressort Leistungssport Samuel Mettler
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