Getting the cutting edge?
Overview
Historical view on diet and performance
 Carbohydrates for the long run?
 Fats for the even longer run?
 Alkalosis for sprinting?
 Nitric Oxide for work economy?
 Drinking too much?

Historical overview

The interest for diet and physical
performance goes back to ancient times
 Already in the ancient Olympic games,
nutrition was a theme of discussion, and
Milo of Croton’s ability of eating was admired
almost as much as his wrestling power
 At the end of 1800’s, physiologists in
Scandinavia and else where, took interest in
how the body used nutrients and the effect
upon performance
1
2
3
Can you name them?
6
4
5
Fridtjof Nansen,
Norway
August Krogh,
Denmark
Archibald Vivian Hill,
UK
Bengt Saltin, Sweden/Denmark
Jonas Bergström,
Sweden
Lars Hermansen,
Norway
Carbohydrates for the long run?
Muscle biopsies

The research developed from the
biopsy technique of Bergström
and Hultman gave new insight
into the depletion of energy
stores during exercise
 This led to the recommendations of:
○ Carbohydrate loading before
exercise
○ Carbohydrate intake during exercise
○ Replenishment of glycogen stores
after exercise
Carbohydrate loading

The original model proposed by
Bergström et al.1 was rigorous:
 1) an exhausting bout of exercise to deplete
the glycogen stores
 2) living and (if possibly) training for three
days on a very low CHO diet
 3) three days of resting and a very high
CHO intake (600 g/day)
 4) competition
1
Bergström, J., Hermansen, L., Hultman, E. ,Saltin, B. Diet, muscle glycogen and physical performance. Acta Physiologica
Scandinavica 1967,71. p. 140-150
Carbohydrate loading
•
The method proved difficult to perform for
especially high performance athletes
• An alternative method was developed
(Blom et al., 1987)1:
– 1)resting for two days with a moderate CHO
intake (400 g/day)
– 2) Competition
•
This method proved more easy to perform,
and gave the same CHO loading as the
original method in trained athletes
1Blom,
PCS Costill, DL Vøllestad, NK. Exhaustive running: inappropriate as a stimulus of muscle glycogen
supercompensation. Med. Sci Sports & Exerc, 19, 398-403, 1987
Blom, Costill, Vøllestad. Exhaustive running: inappropriate as a stimulus of muscle glycogen
supercompensation. Med. Sci Sports & Exerc, 19, 398-403, 1987
CHO intake
Previously, athletes had been advised not to
drink or eat during exercise for fear of GI
problems
 Now the ACSM recommendations was to
drink frequently and take in energy in the
form of CHO beverage

ACSM guidelines
•
•
3. During exercise, athletes should start drinking early and
at regular intervals in an attempt to consume fluids at a
rate sufficient to replace all the water lost through sweating
(i.e., body weight loss), or consume the maximal amount
that can be tolerated
6. During intense exercise lasting longer than 1 h, it is
recommended that carbohydrates be ingested at a rate of
30-60 g · h-1 to maintain oxidation of carbohydrates and
delay fatigue. This rate of carbohydrate intake can be
achieved without compromising fluid delivery by drinking
600-1200 ml· h-1 of solutions containing 4%-8%
carbohydrates (g · 100 ml-1). The carbohydrates can be
sugars (glucose or sucrose) or starch (e.g., maltodextrin)
Convertino, Victor A. (Chair); Armstrong, Lawrence E. ,Coyle, Edward F. ,Mack, Gary W. ,Sawka, Michael N. ,Senay, Leo C. Jr. ,Sherman, W.
Michael . ACSM Position Stand: Exercise and Fluid Replacement. Medicine & Science in Sports & Exercise: October 1996 - Volume 28 - Issue 10 pp i-ix
Getting enough energy?

During hard work, the energy requirements
may exceed what is possible to supply
 Can the amount of energy be increased?
(Jeukendrup, Gleeson,2010, page 138)
Combined ingestion of glucose and fructose
Roy L. P. G. Jentjens, Luke Moseley, Rosemary H. Waring, Leslie K. Harding, Asker E. Jeukendrup. Oxidation of
combined ingestion of glucose and fructose during exercise. J Appl Physiol 96: 1277–1284, 2004.
Combined ingestion of glucose and fructose
Asker E. Jeukendrup Carbohydrate feeding during exercise. European Journal of Sport Science, March 2008; 8(2): 77-86
Mouth rinse?
Performance enhancement has been seen
on exercises that have durations too short to
produce severe glycogen depletion, and
without intake of carbohydrates, only rinsing
the mouth with a sugar solution1
 This finding has been challenged by others2

1 James
M. Carter, Asker E. Jeukendrup, and David A. Jones. The Effect of Carbohydrate Mouth Rinse on 1-h Cycle Time Trial Performance Med. Sci.
Sports Exerc., Vol. 36, No. 12, pp. 2107–2111, 2004.
2 Milou Beelen, Jort Berghuis, Ben Bonaparte, Sam B. Ballak, Asker E. Jeukendrup, and Luc J.C. van Loon. Carbohydrate Mouth Rinsing
in the Fed State: Lack of Enhancement of Time-Trial Performance . International Journal of Sport Nutrition and Exercise Metabolism, 2009, 19, 400409
James M. Carter, Asker E. Jeukendrup, and David A.
Jones. The Effect of Carbohydrate Mouth Rinse on 1-h
Cycle Time Trial Performance Med. Sci. Sports Exerc., Vol.
36, No. 12, pp. 2107–2111, 2004.
Milou Beelen, Jort Berghuis, Ben Bonaparte, Sam B.
Ballak, Asker E. Jeukendrup, and Luc J.C. van Loon
Carbohydrate Mouth Rinsing in the Fed State: Lack of
Enhancement of Time-Trial Performance International
Journal of Sport Nutrition and Exercise Metabolism,
2009, 19, 400-409
CHO repletion
The biopsy data also indicated that a rapid
replenishment of glycogen stores would be
beneficial for the restitution and the near
future training and competition activity
 The advice is to eat about 1.2 g of CHO pr
kg body mass during the first two hours and
then continue to eat CHO for the next hours1

1 Roy
Jentjens and Asker E. Jeukendrup. Determinants of Post-Exercise Glycogen
Synthesis During Short-Term Recovery. Sports Med 2003; 33 (2): 117-144
How much glucose should be ingested after exercise?
Blom, PCS, Høstmark, A.T, Vaage, O., Kardel, K.R, Mæhlum, S.
Effect of different post exercise sugar diets on the rate of muscle
glycogen synthesis. Med Sci Sport Exerc, 1987, 19,(5) 491-497
Testing out Gatorade for the first time
Roy Jentjens and Asker E. Jeukendrup. Determinants of
Post-Exercise Glycogen Synthesis During Short-Term
Recovery. Sports Med 2003; 33 (2): 117-144
Training in a glycogen depleted state?
Anne K. Hansen, Christian P. Fischer, Peter Plomgaard, Jesper Løvind Andersen, Bengt Saltin and Bente Klarlund Pedersen.
Skeletal muscle adaptation: training twice every second day vs. training once daily. J Appl Physiol 98: 93–99, 2005.
Carbohydrate conclusion
“Carbohydrate ingestion can improve endurance capacity and performance. The
optimal dose of carbohydrate is still subject to debate, but recent evidence
suggests that there may be a dose-response effect as long as the carbohydrate
ingested is also oxidized and does not result in gastrointestinal distress. Oxidation
rates of a single type of carbohydrate do not exceed 60 g h-1. However, when
multiple transportable carbohydrates are ingested (i.e. glucose and fructose),
oxidation rates can be increased significantly. To achieve these high oxidation
rates, carbohydrate needs to be ingested at high rates and this has usually been
associated with poor fluid delivery. There are suggestions, however, that using
multiple transportable carbohydrates may enhance fluid delivery compared with a
single carbohydrate.”
Asker E. Jeukendrup .Carbohydrate feeding during exercise. European Journal of Sport Science, March 2008; 8(2): 77-86
Fat for the even longer run?
Dietary fat intake
With limited CHO stores, the idea of
using fat is tempting
 The problem is that fat oxidation
requires more oxygen, so, at high
intensity, CHO must be used
 An approach is to try and spare CHO in
the beginning, saving CHO for the final
sprint

Fat loading




1
Eating a high fat diet for a few days do reduce
endurance performance1
Eating a high fat diet for a few days do not affect
endurance performance2
Eating a fat rich diet for more than a week makes
changes in the resting metabolism3
Attempts to use shorter fatty acid chains (MCT)have
mostly not enhanced performance4
Bergström, J., Hermansen, L., Hultman, E., Saltin, B. Diet, muscle glycogen and physical performance. Acta Physiologica Scandinavica 1967:
Vol. 71. p. 140-150
2 Michael Vogt, Adrian Puntschart, Hans Howald, Bruno Mueller, Christoph Mannhart, Liliane Gfeller-tuescher, Primus Mullis, and Hans Hoppeler.
Effects of Dietary Fat on Muscle Substrates, Metabolism, and Performance in Athletes. Med. Sci. Sports Exerc., Vol. 35, No. 6, pp. 952–960, 2003.
3 Helge, J.W., Wulff, B., Kiens, B. Impact of a fat-rich diet on endurance in man: role of the dietary period. Medicine & Science in Sports & Exercise
Mar 1998: Vol. 30 Issue 3. p. 456-461
4John A. Hawley, Fred Brouns and Asker Jeukendrup Strategies to Enhance Fat Utilisation During Exercise. Sports Med 1998 Apr; 25 (4): 241-257
Fat loading
Michael Vogt, Adrian Puntschart, Hans Howald, Bruno Mueller, Christoph Mannhart, Liliane Gfeller-tuescher, Primus
Mullis, and Hans Hoppeler. Effects of Dietary Fat on Muscle Substrates, Metabolism, and Performance in Athletes. Med.
Sci. Sports Exerc., Vol. 35, No. 6, pp. 952–960, 2003.
IMCL=Intramyocellular lipids
Fat loading
Michael Vogt, Adrian Puntschart, Hans Howald, Bruno Mueller, Christoph Mannhart, Liliane Gfeller-tuescher, Primus Mullis, and Hans Hoppeler.
Effects of Dietary Fat on Muscle Substrates, Metabolism, and Performance in Athletes. Med. Sci. Sports Exerc., Vol. 35, No. 6, pp. 952–960, 2003.
Using MCT as CHO sparer
Mamen, A, Medbø, J.I, Gordeladze, J.O. Effect of fat and L-carnitin ingestion on bicycling
performance. Acta Kinesiologica Universitatis Tartuensis, 2003, 8, 89-105
Fat conclusion
“In some individuals the ingestion of caffeine improves endurance capacity, but Lcarnitine supplementation has no effect on either rates of FA oxidation, muscle
glycogen utilisation or performance. Likewise, the ingestion of small amounts of
medium-chain triglyceride (MCT) has no major effect on either fat metabolism or
exercise performance. On the other hand, in endurance-trained individuals, substrate
utilisation during submaximal [60% of peak oxygen uptake (VO2peak)] exercise can
be altered substantially by the ingestion of a high fat (60 to 70% of energy intake), low
CHO (15 to 20% of energy intake) diet for 7 to 10 days. Adaptation to such a diet,
however, does not appear to alter the rate of working muscle glycogen utilisation
during prolonged, moderate intensity exercise, nor consistently improve performance.
At present, there is insufficient scientific evidence to recommend that athletes either
ingest fat, in the form of MCTs, during exercise, or ‘fat-adapt’ in the weeks prior to a
major endurance event to improve athletic performance.”
John A. Hawley, Fred Brouns and Asker Jeukendrup Strategies to Enhance Fat Utilisation During Exercise. Sports Med,
1998 Apr; 25 (4): 241-257
Alkalosis for sprinting?
Acidosis
 Diet
with a high acid content can
reduce work performance in shorthigh intensity work
 “Exercise time to exhaustion was longer after the normal (p <0.05) and high (p
<0.01) CHO diets compared with the low CHO diet. Pre-exercise plasma
bicarbonate concentration and blood PCO2 were higher after the high CHO diet
when compared with the normal (p = 0.05, p <0.05 respectively) and low CHO
conditions (p <0.05, p <0.05 respectively). Pre-exercise bicarbonate was also
higher after the normal CHO diet when compared with the low CHO diet (p
<0.05).”1
 “Exercise time to exhaustion after the High Fat High Protein diet (179 +/- 63 s)
was shorter when compared with the Normal (210 +/- 65 s; p <0.01) and High
CHO Low Fat (219 +/- 69 s; p <0.05) diets.” 2
1 Greenhaff
PL; Gleeson M; Whiting PH; Maughan RJ. Dietary composition and acid-base status: limiting factors in the performance of
maximal exercise in man? Eur J Appl Physiol Occup Physiol, 1987; Vol. 56 (4), pp. 444-50
2Greenhaff PL; Gleeson M; Maughan RJ. Diet-induced metabolic acidosis and the performance of high intensity exercise in man. Eur J
Appl Physiol Occup Physiol, 1988; Vol. 57 (5), pp. 583-90
Greenhaff, Gleeson, Maughan. Diet-induced metabolic acidosis and the performance of
high intensity exercise in man. Eur J Appl Physiol Occup Physiol ,1988, 57 (5), 583-590
Induced alkalosis

It’s possible to induce alkalotic conditions in
the blood by ingesting sodium hydrogen
carbonate or sodium citrate
 In some cases, this has improved the
performance1

It’s also possible to enhance buffer capacity
by eating low sodium diets
 The effect on performance is barely studied
1 Wilkes,
D., Gledhill, N., Smyth, R. Effect of acute induced metabolic alkalosis on 800-m racing time. Medicine & Science in Sports &
Exercise 1983: Vol. 15 Issue 4. p. 277-280
Wilkes, D., Gledhill, N., Smyth, R. Effect of acute induced metabolic alkalosis on 800-m racing time. Medicine & Science in Sports &
Exercise 1983: Vol. 15 Issue 4. p. 277-280
m = muscle buffer capacity
Nitric Oxide for work economy?
”During moderate exercise, nitrate supplementation reduced muscle
fractional O2 extraction (as estimated using nearinfrared spectroscopy).
The gain of the increase in pulmonary O2 uptake following the onset of
moderate exercise was reduced by 19% in the BR condition (BR: 8.6±0.7
vs. PL:10.8±1.6 ml·min-1·W-1; P<0.05). During severe exercise, the O2
uptake slow component was reduced (BR: 0.57±0.20 vs. PL: 0.74±0.24
L·min-1; P<0.05), and the time-to-exhaustion was extended (BR: 675±203
vs. PL: 583±145 s; P<0.05).”
Stephen J. Bailey, Paul Winyard, Anni Vanhatalo, Jamie R. Blackwell, Fred J. DiMenna, Daryl P. Wilkerson, Joanna Tarr,
Nigel Benjamin, and Andrew M. Jones. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise
and enhances tolerance to high-intensity exercise in humans. J Appl Physiol 107: 1144–1155, 2009.
BR=beetroot juice,
PL=placebo
“In contrast to submaximal work we found no significant effects of nitrate
supple-mentation on the metabolic variables during maximal work. This may be
explained by changes in physiological functions at a maximum level of effort
compared with a submaximal level. During maximal or near maximal work, the
modulatory physio-logical effects by nitrate are likely to be overridden by
emergency reactions.”
Drinking too much?
Drinking too much?
•
•
•
•
The ACSM guidelines for fluid re-placement
has received some critique lately
Professor Timothy David Noakes of Cape
Town, SA has raised concerns about the
necessity of drinking that much1
He has pointed out that hyponatremia is a
more frequent disturbance than dehydration
in marathon races2
Experience from elite athletes also indicate
that the need to replenish all the sweat
during exercise is not required
1T
D Noakes. Drinking guidelines for exercise: What evidence is there that athletes should drink ‘‘as much
as tolerable’’, ‘‘to replace the weight lost during exercise’’ or ‘‘ad libitum’’? Journal of Sports Sciences, May
2007; 25(7): 781–796
2 F G Beltrami, T Hew-Butler, T D Noakes .Drinking policies and exercise-associated hyponatraemia: is
anyone still promoting overdrinking? Br J Sports Med 2008;42:796–801
References
Bailey, S. J., Winyard, P., Vanhatalo, A., Blackwell, J. R., DiMenna, F. J., Wilkerson, D. P., et al. (2009). Dietary nitrate supplementation
reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Journal of Applied
Physiology , 107 , 1144–1155.
Beelen, M., Berghuis, J., Bonaparte, B., Ballak, S. B., Jeukendrup, A. E., & van Loon, L. J. (2009). Carbohydrate Mouth Rinsing in the Fed
State: Lack of Enhancement of Time-Trial Performance. International Journal of Sport Nutrition and Exercise Metabolism , 19,
400-409.
Beltrami, F. G., Hew-Butler, T., & Noakes, T. D. (2008). Drinking policies and exercise-associated hyponatraemia: is anyone still
promoting overdrinking? British Journal of Sports Medicine , 42, 796–801.
Bergström, J., Hermansen, L., Hultman, E., & Saltin, B. (1967). Diet, muscle glycogen and physical performance. Acta Physiologica
Scandinavia , 71, 140-150.
Blom, P. C., Costill, D. L., & Vøllestad, N. K. (1987). Exhaustive running: inappropriate as a stimulus of muscle glycogen
supercompensation. Medicine & Science in Sport & Exercise, 19, 398-403.
Blom, P. C., Høstmark, A. T., Vaage, O., Kardel, K. R., & Mæhlum, S. (1987). Effects of different post exercise sugar diets on the rate of
muscle glycogen synthesis. Medicine and Science in Sport and Exercise , 19 (5), 491-497.
Carter, J. M., Jeukendrup, A. E., & Jones, D. A. (2004). The Effect of Carbohydrate Mouth Rinse on 1-h Cycle Time Trial Performance.
Medicine & Science in Sports & Exercise , 36, (12), 2107–2111.
Edge, J., Bishop, D., & Goodman, C. (u.d.). Effects of chronic NaHCO3 ingestion during interval training on changes to muscle buffer
capacity, metabolism, and short-term endurance performance. Journal of Applied Physiology , 101, 918-925.
Greenhaff, P. L., Gleeson, M., & Maughan, R. J. (1988). Diet-induced metabolic acidosis and the performance of high intensity exercise in
man. European Journal of Applied Physiology and Occupational Physiology , 57 (5), 583-590.
Greenhaff, P. L., Gleeson, M., Whiting, P. H., & Maughan, R. J. (1987). Dietary composition and acid-base status: limiting factors in the
performance of maximal exercise in man? European Journal of Applied Physiology and Occupional Physiology , 56 (4), 444450.
References
Hansen, A. K., Fischer, C. P., Plomgaard, P., Andersen, J. L., Saltin, B., & Pedersen, B. K. (2005). Skeletal muscle adaptation: training
twice every second day vs. training once daily. Journal of Applied Physiology, 98, 93-99.
Hawley, J. A., Brouns, F., & Jeukendrup, A. E. (1998 ). Strategies to Enhance Fat Utilisation During Exercise. Sports Medicine , 25 (4 ),
241-257.
Helge, J. W., Wulff, B., & Kiens, B. (1998). Impact of a fat-rich diet on endurance in man: role of the dietary period. Medicine & Science
in Sport & Exercise , 30 (3), 456-461.
Jentjens, R. L., Mosles, L., Waring, R. H., Harding, L. K., & Jeukendrup, A. E. (2004). Oxidation of combined ingestion of glucose and
fructose during exercise. Journal of Applied Physiology , 96, 1277-1284.
Jentjens, R., & Jeukendrup, A. E. (2003). Determinants of Post-Exercise Glycogen Synthesis During Short-Term Recovery. Sports
Medicine , 33 (2), 117-144.
Jeukendrup, A. E. (2008). Carbohydrate feeding during exercise. European Journal of Sport Science , 8 (2), 77-86.
Jeukendrup, A. E., & Gleeson, M. (2010). Sport Nutrition. Champaign: Human Kinetics.
Larsen, F. J., Weitzberg, E., Lundberg, J. O., & Ekblom, B. (2007 ). Effects of dietary nitrate on oxygencost during exercise. Acta
Physiologica , 191, 59-66.
Mamen, A., Medbø, J. I., & Gordeladze, J. O. (2003). Effect of fat and L-carnitin ingestion on bicycling performance. Acta Kinesiologica
Universitatis Tartuensis , 8, 89-105.
Noakes, T. D. (2007). Drinking guidelines for exercise: What evidence is there that athletes should drink ‘‘as much as tolerable’’, ‘‘to
replace the weight lost during exercise’’ or ‘‘ad libitum’’? Journal of Sports Sciences , 25 (7), 781–796.
Vogt, M., Puntschart, A., Howald, H., Mueller, B., Mannhart, C., Gfeller-Tuescher, L., et al. (2003). Effects of Dietary Fat on Muscle
Substrates, Metabolism, and Performance in Athletes. 35 (6), 952-960.
Wilkes, D., Gledhill, N., & Smyth, R. (1983:). Effect of acute induced metabolic alkalosis on 800-m racing time. Medicine & Science in
Sports & Exercise , 15 (4), 277-280.