Recovery Antagonized Training at
the 2014 Meeting of the American College of Sports Medicine Louise M Burke1, Jeni
Pearce2, David T Martin1, Will G Hopkins2,3 Sportscience 18, 8-17, 2014 (sportsci.org/2014/ACSM.htm) 1 Australian
Institute of Sport, Canberra, ACT, Australia; Email. 2 High Performance Sport NZ, Auckland, New
Zealand; Email. 3 Victoria University, Melbourne,
Victoria, Australia; Email. Reviewer: Randy Wilber, US Olympic
Committee, Colorado Springs, Colorado.
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The
annual meeting of the American College of Sports Medicine (this year in Orlando,
Florida, May 27-31) was again a joint conference not only for Exercise is Medicine
but also for a world congress on the role of inflammation in exercise, health
and disease. Sport performance–the focus of this report–was therefore represented
by only a minor proportion of the ~3500 presentations, but there were enough fascinating
findings to make up for the shortfall in quantity. This
report is a joint effort by Louise Burke, Jeni Pearce, Dave Martin and Will
Hopkins. Louise, Jeni and Dave attended the meeting and have provided
first-hand accounts of keynote and other featured presentations, none of
which have abstracts. As usual, Will did not attend the meeting but has summarized
the abstracts of the slide and poster sessions, where all the new research
was presented. The ACSM conference
site provides various links to information
about the meeting, and you can access the conference abstracts via this link. Use the advanced search form (Ctrl-Shift-F)
in Adobe Acrobat to find abstracts featured in this report via the number in
brackets […]. (Numbers with a letter in front indicate sessions: A for
Wednesday morning through G for Saturday morning.) You will get several hits,
but you can quickly home in on the right one. The abstracts are also freely
available in the May
supplement of Medicine and Science in Sports and Exercise,
but searching for individual abstracts via the abstract number with the
advanced search form (enter 46 in the Volume field and 5s in the Issue field)
is inefficient. with Louise Burke
Over
the past couple of years, the day preceding the official start of the ACSM annual
meeting has become a ritual for those interested in sports nutrition: a symposium
sponsored by the Gatorade Sports Science Institute and a special event organized
by PINES (Professionals in Nutrition for Exercise
and Sport). The talks in the symposium may soon be available at the GSSI website, while the PINES event will be reported
in full at the PINES site and in International Journal of Sport Nutrition
and Exercise Metabolism. Meantime, here are my summaries and a summary
of special presentations on nutrition at the ACSM meeting itself. GSSI
Symposium
The Future of Sports Nutrition commenced
with a presentation from Asker Jeukendrup, who took us back through the
history of sports nutrition (diets of ancient Olympians, early Tour de France
eating quirks) before predicting that the future would involve greater
emphasis on nutrition
solutions for individual athletes. My contribution on supplements straddled three topics: benefits (providing practical ways to meet nutrient
intake goals, preventing/treating nutrient deficiencies, in a few cases
achieving a direct performance enhancement, and delivering a valuable placebo
effect); risks (distracting athletes from tackling more important
performance factors; emphasizing the overhyped products or chaotic patterns
of use in favor of evidence-based products used appropriately, toxicity and
side-effects, inadvertent anti-doping rule violations); and regulation (national
regulation of food and drugs, anti-doping codes, rules within sports systems,
public opinion). Matthew Pahnke
discussed common causes of gut ischemia and disturbance during exercise (type
and intensity of exercise, exercise nutrition, genetics) as well as remedial actions
(gut
tolerance training for fluid and carbohydrate intake, potential
use of products such as glutamine and nitrate supplements to enhance
gut perfusion). Luc van Loon updated guidelines
for protein intake to promote exercise adaptation, including recommendations for
protein type
(high content of leucine), amount (20-25 g serves) and timing (post-exercise,
spread every 3-5 hours over the day, pre-bed). Daniel Medina completed the session by describing
the systems, resources and protocols needed to implement a nutrition
program spanning food service, education, counselling and supplement
use within a professional football team (Barcelona FC). PINES
Special Event
We continued
the tradition of having 10 experts respond to 10 questions with three slides in
three minutes, followed by interaction with the audience. The 2014 theme addressed the search by athletes for the next superfood or phytochemical that can improve performance, recovery, body
composition or resilience (to illness or injury). 1. Is watermelon (a
source of citrulline ) another stimulant of nitric oxide,
and would a watermelon/beetroot cocktail be the ultimate red “go fast” juice?
Andy Jones: potentially interesting but watermelon doesn’t contain enough
citrulline. 2. Do exotic cherries and berries
offer benefits to sports performance? Phillip Bell: perhaps, but optimal use
to reduce muscle soreness is not clear. 3. How much creatine, carnitine and carnosine did our cave-dwelling ancestors consume in their daily
diets? Must modern athletes turn to supplements to achieve optimal levels of
these components? Roger Harris: hard to be definitive, but probably, and yes.
4. What’s the latest on food polyphenols and how should athletes consume them? David Nieman: still
no evidence to support single use of foods or supplement polyphenols;
cocktails may solve bioavailability. 5. Does curcumin offer any benefits to chronic inflammation or bone health
in athletes at high risk, and how should it be consumed? Ashley Smuder: interesting
but too early to be sure. 6. Can green-tea extract help athletes to manage their body composition? Rebecca
Randall: evidence for an extra 1 kg loss of body fat in treatment for obesity
but unlikely to be worthwhile for athletes. 7. Are athletes interested in synthetic antioxidants targeting mitochondria and do they offer performance benefits? Scott Powers: no evidence
that such antioxidants are useful for sports performance. 8. Are there differences between caffeine from gum, coffee and other sources when it comes to athletic performance? Lawrence Spriet: modest caffeine intakes from all sources
may offer performance benefits in various sports. [WGH: if you have to say "may"
about the effect of caffeine, there's no point in doing any research on
athletic performance.] 9. Do any vegetable protein
sources match the value of whey for muscle protein synthesis, and how can
they be manipulated to increase their value for muscle adaptation? Luc van
Loon: most vegetable proteins are lower in leucine content than whey but
could be fortified with this important amino acid. 10. How easy is it to take a new superfood from research
evidence to commercial production? Eric Zaltas: the pathway is lengthy, but you meet some interesting
characters along the way. ACSM Meeting
My
personal highlight was a symposium on the two-hour marathon, which followed
up a popular point-counterpoint in Journal of Applied Physiology in
2011. Sandra Hunter dissected several
strategies to determine the equivalent to the two-hour barrier in female marathon
runners. In some experts' opinions, the current
world record of 2:15:25 by Paula Radcliffe has already surpassed this mark, implying
that the best woman is relatively better than the best man. Mike Joyner reviewed the characteristics of
world-best
marathon runners (small physique, lifelong training, altitude
natives) and extrapolated the theoretical equivalent of the current world 10-km
record (26:20) to a 2.01-2.02 h marathon. Andy Jones discussed the limitations
in sustainable metabolic rate and running economy to running at 21.1 km/h for
2 hours. He noted that running
economy could be improved by strategies such as drafting, increasing
reliance on carbohydrate as muscle substrate, and using nitrate
supplementation. He outlined the physiological formula for the runner who
could theoretically achieve the feat by sustaining a fractional utilization
of 80% of a VO2max of 80 ml/kg/min with a running economy of 180 ml/min/km) in
the right race conditions (strategic drafting, a flat course and a cool
day). Alejandro Lucia finished by
discussing various genetic traits that might assist marathon running, noting
that Asia might be the home of the runner most suited to a world-best marathon
time. A
symposium on the effects of mild hypohydration on
exercise revealed assessment tools to monitor small deficits in body water
(Lawrence Armstrong), interaction of dehydration and environment on body
temperature and performance (Doug Casa), evidence of possible changes in metabolism
during exercise, such as glycogen utilisation (Lawrence Spriet), and evidence
for performance changes (Stavros Kavouras).
The 2014 review of hypohydration and exercise by Cheuvront and
Kenefick in Comprehensive Physiology
provided a frequently cited resource for this session. A
colloquium discussed the outcome of strategies to reduce the health risks associated
with weight-making
practices in collegiate wrestling. Strategies introduced following
the deaths of three wrestlers in 1991 included a change in weight categories,
the movement of the weigh-in time until 2 h prior to wrestling, the establishment
of a minimum wresting weight equivalent to 5% body fat, and a maximum rate of
weight loss allowed over the season. Important features of the changes included
enforcing rules in practice and an emphasis on competition performance rather
than ability to make weight. Although
there has been a reduction in the amount of weight lost acutely before
weigh-in and regained afterward, there is still evidence of abuse and only a
minority of athletes has a weight-making plan. Updated information on weight-making
practices in combat sports can be found in the report from a survey of
athletes who competed at the 2012 Olympic Games (Gibson, International Journal of Wrestling Science 2013). Ron
Maughan and I conducted a tutorial on the outcomes of the FINA consensus
meeting on Nutrition for Aquatic Sports, held in London in December 2013.
We reviewed the findings of a group of expert practitioners,
scientists and administrators from the sports of pool swimming, open-water
swimming, diving, water polo and synchronized swimming. Separate summaries were made of the challenges
and strategies of optimal nutrition for each of these aquatic disciplines,
along with the common issues of physique and body image concerns, use of dietary supplements,
managing illness
and injury, and coping with
travel and special environments.
Outputs from this meeting include a series of reviews in International Journal of Sport Nutrition and Exercise Metabolism
and education resources for athletes and coaches, available (eventually) via this link at the FINA site. Anne
Loucks provided a tutorial update on the treatment of low energy availability in
female athletes. She noted differences
between energy availability and energy balance. Energy availability (energy
intake minus the energy cost of exercise) is under voluntary control, unlike
energy balance, where resting metabolic rate accounts for ~2/3 of energy
expenditure and can be suppressed. Errors
in measurement of fat free mass, exercise energy expenditure and energy
intake contribute to the substantial error in energy availability, but it
remains a useful concept for dealing with the “healthiness” of dietary
patterns of athletes, particularly in weight-conscious sports. I contributed to this session by summarizing
the strategies used to assess and modify low energy
availability with a wholistic approach to the quality and quantity of food
choices, the achievement of specific nutritional support around training
sessions, and a restoration of the inclusion of social interaction and enjoyment
around eating. Finally,
I concluded a busy conference program by conducting a tutorial on implementing
strategies to train with low glycogen (“train low”) in a periodized training and nutrition
program. I noted that this concept is
frequently misunderstood or oversimplified and that current studies of train-low
strategies have failed to see performance benefits probably because they fail
to sufficiently simulate the complex interaction of “train high” and “train
low” sessions in the ideal periodised training program. Examples of such programs were provided
from a range of different sports. with Jeni Pearce
The
Tuesday preconference, organized by Gatorade and PINES, were a great way for everyone
interested in sport nutrition to start the conference (over 300 people
attended each). These two sessions
will be back in 2015. There
is much work to be done in the area of a healthy microbiome (gut bacteria).
Have a century of antibiotic use and abuse finally come back to haunt
us? The metabolism and biochemistry sessions addressing this issue were interesting
but did contain sufficient evidence for changes in current best
practice. Authors
of only one of the many posters on supplements had checked the composition of
the supplement and had it tested for banned substances. (The Informed Sport logo was on the poster.). Many of these
studies showed the expected benefits of caffeine, and several reported no
benefits from a range of herbal products (also to be expected). Of concern was a study showing that the
banned substance DHEA worked–not the message I felt should be promoted. The
presenter wasn't there when I went to ask how they got the study approved. A
great session from the US Olympic Committee covered the impact of the medical, dental
and nutrition services over the last two Olympic Games (London and
Sochi). The dental session was particularly brutal, with photography of all
the injuries highlighting the importance of mouth guards, especially the high
quality three-piece bonded variety. Nanna Meyer (USOC sports dietitian from
Colorado) gave a great overview of the sport nutrition strategies and
management of the USOC winter speed skating team she has worked with for 15
years. Young practitioners benefited from this session by seeing the
influence of a sports dietitian at the team and individual level, the commitment
and creativity required, and the application of research and experience. Nanna reviewed the challenges at international
events and the focus on making sure basic requirement are met. Janice
Thompson's presidential lecture reminded those of us in the field of
nutrition of the wider global and cultural impact of our work. My
take home message… Louise's session on carbohydrate availability should be compulsory
for all practitioners prescribing the train-low (carbohydrate) strategy. It is crucial for practitioners to
understand low energy availability and to be on the alert for it, as there
are adverse effects on performance and especially training if the more
familiar markers are absent (low BMI, body fat and bone density). with Dave Martin
Thirty-one posters were presented under
the heading Characterizing the Competitive Athlete
[230-260], including collegiate football, swimming, soccer, lacrosse, ice
hockey, wrestling track and field, race walking, team handball, table tennis,
and even NASCAR Sprint Cup pit crew.
As new technologies make it easier to monitor heart rate, respiratory
rate and skin temperature during training and competition, there is an
increase in descriptive studies. The challenge of course is to ensure that the
technology is used to address interesting research questions. Effects of
manipulating body mass on performance in rowing [258] and wrestling [253]
were addressed and the topic of functional movement screening continues to
attract interest [245, 257], although methodology in this area is highly
variable. The belief (aka placebo)
effect was addressed in an excellent highlighted symposium. Neurobiology techniques are now being used
to understand how belief influences efficacy of pain medication. Prof. Benedetti
outlined a unique experimental design that uses naloxone, a drug that blocks
endogenous opiate receptors. In a series of studies blinded use of naloxone
prevented expected placebo effects, suggesting that expectations result in
positive shifts in neurotransmitter states within the brain. Contemporary
data in this area indicate that in many cases it is important for the physician
(and likely the coach and sport scientist) to make sure that their client
believes in treatment strategies. Neuromuscular fatigue
was addressed in an interesting thematic poster session [A-27]. Researchers
presenting in this session focused on manifestations of central vs peripheral
fatigue. Indicators of central fatigue appear to recover quickly following
exhausting exercise with measureable changes occurring within 3 min [96].
Amann’s team from University of Utah are now suggesting that the central nervous
system tolerates peripheral fatigue to a greater extent when group III/IV
afferent feedback comes from small
muscle mass [100]. Despite this
finding, recovery following upper and lower body exercise to exhaustion was
shown to be similar using cycling ergometry [98]. Japanese researchers addressed the effects
of CO2-enriched
water on muscle recovery [97] using a well thought-out experimental design.
Positive results are either artifact, placebo or
real and interesting. Concussion
in sport is currently a hot topic and is now attracting interest from
physicians, physiologists and sports administrators. Numerous studies were presented
quantifying head trauma, describing physiological manifestation of head
impact, and also documenting recovery from insult [A-31, B-29, B-68, D-51]. Thermoregulation
continues to attract attention.
Gastrointestinal health was compromised in both ultra-distance runners
[708] and cyclists [709], and body temperature was implicated in both
cases. Tyrosine ingestion produced promising
cognitive results for soccer players who were asked to exercise in the heat
[721]. The topic of mobile monitoring
from a biomechanics perspective allowed four interesting researchers to
address emerging technologies and methodology. Thor Besier from New Zealand
is really pushing the boundaries of using inertial measurement units combined
with haptic feedback to understand and then improve movement patterns.
Although Thor’s work is primarily focused on movement disorders, there may be
application for elite sport. The ability to use technology to improve the
rate of skill acquisition without creating a co-dependence on feedback will
remain challenging. High-intensity
training
was the topic of a thematic poster session [B-64]. Both aerobic and anaerobic
fitness can improve following 6 wk of cross-fit training [1040], high blood
flow stimulation aids in recovery between high intensity exercise bouts (30-s
Wingate) [1042], and regulating cycling cadence can minimize fatigue for
“all-out” 30-s sprints [1039]. I was involved in a symposium entitled Unique Case Studies: Olympic Champions and the Impact of Sport Science on Performance.
A take-home message from my perspective was that there are many unique ways a
sport-science team can work to improve Olympic performance; for example,
skating efficiency for Dutch speed skaters, reduced risk of injury for US
track and field athletes, pacing for US marathon runners, and providing
general support and advice through adverse and challenging training camps for
a developing Tour de France champion. Overall, helpful sport scientists work
within the cultural expectations of the high-performance sporting program. Findings from a series of unique studies focusing
on the Leadville 100 ultra-endurance
race (100 miles at 9,200-12,600 ft) indicated that human athletes are
remarkable at adapting to unique environmental challenges. Athletes tend to
self-regulate pacing strategies to ensure energy reserves are distributed
appropriately. Cognitive aspects of the event and fatigue management present
unique topics for further research. The following day Prof. Ron Maughan
chaired a thematic poster session on Endurance
and the Ultra-endurance Athletes [D-60].
Documenting nutrition strategies associated with extreme duration
cycling and running events were the primary topics of interest. A colloquium on Deaths in Wrestling
highlighted that when it comes to elite sport what we know and what we do
with the knowledge are not always connected. A tremendous amount of attention
has focused on why wrestlers have died while trying to make weight, but
because of the competitive nature of elite sport there will always be those
who push the boundaries. Unique rules that constrain behavior are required if
measures to increase safety in sport are to be adopted–especially if risky
behavior is associated with winning. A very enjoyable symposium entitled Evidence Informed Sports Medicine
clearly reviewed the meaning behind many buzz words such as evidence-based and objective evidence. Practitioners from
the USA, Canada and the Netherlands talked about the mystique that is
associated with elite sports medicine. Carl Foster and colleagues reviewed the
topic of stress testing
for fitness assessment. Although they focused on clinical populations, some
of the themes associated with accuracy and reliability of testing, in
addition to clear definitions, were relevant for those testing elite
athletes. Some provocative concepts associated with
limitations to exercise performance at altitude
were discussed during a symposium chaired by Prof. Peter Raven on Human Cerebral Blood Flow. Apparently
oxygenation of the brain is substantially modified by exercise, and conversely
the adaptations can impact exercise performance. The altitude theme was also
central to the Dill Historical Lecture presented by Prof. Benjamin
Levine. The very rich history of
altitude research was reviewed with an impressive collection of historical
pictures. Many of the contributions made by now famous US, German, Spanish,
Scandinavian and Australian researchers were acknowledged. The impact of altitude training on many
physiological adaptations has now been well documented. Future topics worthy
of investigation include understanding the individual variability associated
with adaptations to hypoxia, and why physiological adaptations (e.g.,
increase in hemoglobin mass) can be uncoupled from physical and mental
performance. Epigenetics and Exercise Adaptations
was the topic of a symposium with a keynote delivered by Prof. Mark
Hargreaves. Evidence was presented that phenotype changes induced by exercise
are sometimes due to chemical modifications to DNA. However, the ability for
the sport scientist to act on this provocative information in a practical
manner remains challenging. Although I didn’t attend, I was intrigued
to see a colloquium promoting physical activity in airports.
For all of us that travel the world with coaches and athletes the idea that
physical activity can take place within an airport is relevant. Those working with Paralympic athletes
would have enjoyed the symposium chaired by Dr Walter Thompson on Challenges in the Autonomic Control in Elite Athletes with a Physical Impairment. This symposium addressed cardiovascular control,
thermoregulation and blood-pressure themes. Antidoping
themes were discussed and reviewed by Matthew Fedoruk from the USADA. He believes
that the biological passport is having very positive effects in sports like
cycling with widespread doping problems.
Research clarifying normal responses in elite athletes continues to be
valuable for those attempting to detect abnormal physiology. Michael Joyner from the Mayo Clinic
chaired a symposium discussing the physiological and scientific aspects of a
2-h marathon [F-05]. Dr Andy Jones believes
that Paula Radcliffe has already run the equivalent of a man’s 2-h marathon,
based on how much faster she is than all other female runners. The entire
symposium presented a practical perspective to theoretical limits of human
physiology.
Why running records continue to fall with each successive generation despite
similar physiological characteristics over the past five decades is an interesting
question. How the brain
influences exercise capacity and how exercise influences the brain was the
topic if a well-researched tutorial lecture delivered by Dr Romain Meeusen.
Unique experimental models are revealing the role of the brain in controlling
fatigue in hot conditions and at altitude. The effects of dehydration
on sporting performance has become controversial, as conservatives continue
to warn athletes of the dangers associated with mild dehydration (~2% of body
mass), whereas a bold minority point out that some of the best performing
endurance athletes have the greatest dehydration after a race. Dr Kavouras
chaired a symposium in which hydration experts Drs Armstrong, Casa and Spriet
asserted that the evidence continues to support the advantages of hydration
prior to and during endurance exercise. As a sport scientist involved with many
interdisciplinary teams, I was excited to hear insights into the much publicized
Redbull Stratos project supporting Felix Baumgartner's world record free-fall
parachute jump
from the edge of the earth’s atmosphere.
Bottom line for a successful sport-science project: use the best
people you can afford, look for genuine interest and buy-in, and make sure
everyone understands their roles and responsibilities. It was clear that even aerospace engineers
love a creative ambitious challenge and the chance to push boundaries. How
much money did Redbull invest in this project? "A lot." with Will Hopkins
The
title of this report was inspired by my choice for the top presentation, a poster
showing harmful effects of cold-water immersion on strength training. My other medal
winners were also hidden in the poster ghettos: effects of a warm-up with a weighted vest on economy and performance in distance
runners, and the use of baseline heart-rate variability to predict individual responses to high-intensity
and high-volume endurance training. In
other presentations worthy of special mention, I could find no evidence
supporting the use of nitrate and carbohydrate mouth rinsing with highly trained athletes, but the
taste of quinine may push sprinters to a higher level. Neuromuscular training also reduces risk of injury in team
sports. Acute
Effects
Warm-up with
a weighted vest improved peak running speed in an incremental test by an amazing
2.9% and running economy by 6.0% compared with no vest in a crossover with 11
well-trained distance
runners. Relationships between change scores showed
that changes in leg stiffness could explain all the improvements in
performance and economy. Wow! [3528] A
high-intensity isometric warm-up produced a peak increase (4.9%) in
maximal horizontal bat velocity 6 min later in 28 experienced female softball
players. [932] Various
warm-ups
increased the carry distance of the ball in a comprehensive crossover study
of 30 highly proficient female golfers, but unfortunately the authors haven't
provided enough data to assess which is likely to be best. [959] A
bench-press in the warm-up potentiated shot-put performance by 1.2% vs
control, while back squat had a potentially harmful effect (-0.8%), in a
crossover with 10 collegiate athletes. [2993] Performing
weighted or non-weighted box jumps with varying rest intervals as a warm-up did
not affect vertical jump performance in 20 recreational athletes. [3004] Correlates
of Performance
A few
of 21 gene
polymorphisms previously associated with endurance performance
also turned up as statistically significant in the comparisons of a sample of
154 competitive Japanese endurance runners with 649 controls, but a score representing
how many such genes were present did not differ significantly between the two
groups [687]. No magnitudes were shown, but with this sample size,
non-significant means trivial, and even some of the significant associations
may have been trivial. Conclusion: genotype screening for endurance ability
is still not worthwhile. But
the presence of several gene polymorphisms had a moderate
association with injury incidence and severity in four seasons of play by 54
male professional soccer players [689]. Could this finding be useful for team
selection? Two
putative gene
loci for elite sprint performance have been identified in what
looks like a meta-analysis of three previous studies of Jamaicans,
African-Americans and Japanese sprinters. [2254] Nutrition
and Drugs
"Acute
supplementation with dietary nitrate appears to have no effect on endurance
performance and adds nothing to the benefits afforded by caffeine supplementation"
in this crossover study of 14 competitive female cyclists. Relative to placebo,
the effects of caffeine alone and nitrate alone on mean power in the 20-km
time trial were 5.7% (that's unusually high) and 0.0%, but the effect for
caffeine plus nitrate vs placebo was apparently non-significant and wasn't
shown, and of course there were no confidence limits. Louise Burke pointed
out that the dose of nitrate was probably inadequate, so the way this study was
reported does not provide evidence for or against the use of nitrate in
highly trained athletes. [545] "Acute
[whole-body] exposure to UVA light has recently been shown to
increase nitric oxide bioavailability", and it bestowed a presumably
unclear extra 0.6% benefit to the effect of nitrate supplementation on 16-km time-trial time in a crossover of
nine trained cyclists.
But the effect of nitrate alone vs placebo wasn't significant and can't be
estimated from the data shown. A novel approach, yes, but even if it works,
it's impractical. Why not just up the dose of nitrate? [546] In
two studies of non-athletes the effects of nitrate (via beetroot juice)
on performance were inconclusive [548, 550]. OMG,
consuming beetroot juice vs nitrate-depleted placebo juice before a 5-km
run impaired performance by a
significant 1.6% in this double-blind crossover study of 11 male and two
female runners.
Louise Burke: "Unless they were running up the side of Mount Everest,
these aren’t really runners." True, but in previous studies any
beneficial effect of nitrate has tended to be greater in less trained
individuals, so for me this is more evidence against prescribing nitrate for
top athletes. [549] In
this crossover study of the acute (?) effect of consumption of dark
chocolate (containing epicatechin antioxidants) vs white
chocolate, nine male participants went 13% further in a 2-min time
trial. There is no information about the dosage and timing of supplementation
or the quality of the chocolate! Depending on the cycle ergometer, the
enhancement in power output would be at least 13%. Too good to be true, but
obviously worth further investigation. [2717] Combined
glucose
and fructose
ingestion produced a likely enhancement of time-trial time of 3.0% vs
isocaloric high glucose but an unclear 1.2% enhancement vs moderate glucose
in a crossover when eight trained male cyclists performed a 30-km time trial after a
2-h preload. I'd supplement with glucose plus fructose. [615] Ingestion
of tyrosine
5 h before a soccer-specific simulation test in the heat had a small
beneficial effect on vigilance and a moderate effect on a measure of alertness
in a crossover with eight recreationally active male soccer players. Might be worth a
try, pending more evidence. [721] Compared
with control supplementation with carbohydrate, adding protein or L-alanine
to the supplement tended to impair
performance (both by 1%) of a 30-km time trial following a 120-min preload in
this crossover study of four female and four male cyclists. [172] Compared with placebo mouth rinsing, carbohydrate
mouth rinsing in the fasted or fed state had negligible (0.4%) or harmful
(-1.1%) effects on distance covered in a 1-h cycling time trial in a
crossover with 10 male and 2 female endurance athletes.
But the distance was only ~28 km, so either the ergometer was badly
calibrated for distance or these athletes weren't cyclists [619]. A carbohydrate
mouth rinse had negligible effects on a 30-min cycling time trial with 13 active
males
[620], but it resulted in a 3.6% faster time to complete a 12.8-km run in 11 subjects,
while the run was 2.7% faster with a non-caloric sweet mouth rinse
[621]. My conclusion is that mouth rinsing
is likely to have negligible effects with highly trained athletes. In any
case, swallow the carbohydrate to get the metabolic benefit. Incredibly, a mouth rinse with a bitter-tasting quinine
solution immediately before a 30-s all-out sprint improved mean power by
2.4-3.9% compared with rinsing with aspartame or water or no rinse in a crossover
with 14 male cyclists.
Partly a placebo effect? Wait and see if it declines like that of the
carbohydrate mouth rinse. [618] Ammonia
inhalants
don't seem to have any substantial acute effects on explosive [929] or sprint
[940] performance. Caffeine continues to benefit endurance performance acutely.
There was a 3.7% reduction in swim time and a 1.3% reduction in overall
performance time in actual triathlons when 26 triathletes consumed caffeine
vs placebo (timing and dose not stated). The claim that the effect was not as
pronounced as seen in previous laboratory trials seems to me to be incorrect;
perhaps it relates to unstated effects in the cycle and run stages [2748]. Caffeine
worked equally well in female and male cyclists [2755]. Caffeine had beneficial
effects on intermittent cycling [2749] but "equivocal"
effects on anaerobic performance [2751].
It looks like you might need the C allele of the cytochrome p-450 gene
to benefit from caffeine [2750], but the study had only seven participants. "The
addition of HMB
(beta-hydroxy-beta-methylbutyrate) and waxy maize to whey protein is able to
provide additional benefits to the recovery process, evidenced by a reduction
in muscle damage markers, soreness and an improvement in athletic
performance." That's the reasonable conclusion in this crossover study
in 13 men
who supplemented with EAS Recovery Protein vs whey-protein control twice
daily for 2 wk prior to, during, and for 2 d following a 3-d intense workout
sequence. The improvements in vertical-jump power on Days 4 and 5 were 13%
and 12%. That's great, but for relevance to recovery during a tournament,
what really matters is effects on performance on Days 2 and 3, which
apparently weren't significant. Better recovery on Days 4 and 5 is likely to mean
impaired adaptation later on. [381] Montmorency
(tart) cherry
juice vs placebo consumed 5 d prior to 3 d following a 1.8-h cycle
test improved the maximum force of voluntary isometric contractions and
reduced markers of inflammation in 16 trained male cyclists. So cherry juice is like other dietary
antioxidants in this respect, and it may be beneficial in a tournament
scenario, but does it help or harm adaptation to training? [1450, 1451] Chocolate
milk continues to be better than a carbohydrate drink for
recovery, this time in swimmers. [623] An
extract (of roots?) of Rhodiola crenulata (an alpine herb high
in antioxidants and used to reduce acute mountain sickness) significantly
enhanced endurance performance relative to placebo in a controlled trial of
18 male subjects
who trained for 2 wk at sea level and 2 wk at altitude, but there were no
supporting data in the abstract. Use it to augment altitude training? Wait
for better evidence, or do a study yourself. [2722] Recreationally
trained college-aged males (n=23) randomly assigned in double-blind
fashion to placebo or naproxen treatment groups before training
sessions increased their strength by 27% and 29% respectively following 6 wk
of training. Evidently the anti-inflammatory
drug did not attenuate adaptation to the training. The effect needs to be
investigated in competitive athletes. [2719] Training
In a
controlled trial, 21 young men experienced in resistance training were assigned
to high-intensity
resistance training twice a week for 12 wk. One group recovered
from each session with 10 min of lower-body cold-water immersion (10°C),
while the other group performed low-intensity cycling. The cold-water immersion
group experienced clear substantially less gains in most measures of strength,
the differences in the changes ranging from moderate to very large. [904]
Yikes! Well, it fits the new paradigm: enhance recovery and you impair
adaptation. On-court
interval
training tended to be better than off-court training for various
measures of performance in this randomized controlled trial of 20 youth tennis
players. [933] Here's
yet another study showing you can get at least as much benefit in endurance
performance from low-volume high-intensity interval training as from high-volume
endurance training, this time in a 2-wk randomized controlled trial of 15 Gaelic
footballers.
[942] Tapering
with heavy loads had a slight edge for throwing performance compared with
light loads in a crossover with seven male and six female young throwers,
and there was a clear advantage of heavy loads on measures of strength. [656] In accommodation
resistance training, "chains are either added on a
free-weight bar and combined with traditional plates or added to the bar as
the entire load." In a 4-wk randomized controlled trial with 24 trained
males,
gains were greater in the accommodation group compared with a constant-resistance
group for maximal strength in the upper (16% vs 15%) and lower body (39% vs
22%), and for power in the upper (7.0% vs 4.2%) and lower body (6.6% vs
4.7%). [3335] Neuromuscular training, according to one site, is
a way to teach your body better habits for knee stability. In a meta-analysis
of 23 randomized controlled trials, exercise-based interventions effective in
reducing injury risk in team sports included multifaceted neuromuscular training
and balance-board exercises. [1543] A meta-analysis of 14 randomized controlled
trials supported the prophylactic effectiveness of neuromuscular training
interventions to reduce ACL injury in female soccer. [2816] The
Brazilians have developed a system to track training and other aspects of their elite
athletes:
"a computational approach of SAHA system to optimal sportomic
analyses." It appears to be novel and potentially valuable, but I can't
understand the abstract. [3359] A measure of heart-rate variability (high-frequency power?)
was measured overnight at the end of 8 wk of low-intensity endurance training
in 29 recreational endurance runners, who were then assigned in balanced
fashion to either high-intensity training or high-volume
training for 8 wk. The
change in peak running speed in an incremental treadmill test was greater in
the high intensity group (3.1% vs 0.5%). Remarkably, baseline heart-rate
variability had strong correlations with the individual changes in peak speed
(-0.66 in the high-intensity group, +0.61 in the high-volume group).
Conclusion: "[high] training volume should be recommended for
individuals with low baseline HRV while high intensity training is more
suitable for individuals with high HRV." Wow! [3344] with Randy Wilber
As
noted in the opening paragraph of this comprehensive 2014 ACSM summary
report, the number of papers, symposia, and tutorial sessions devoted to
sport performance is relatively small compared to those devoted to various
aspects of Exercise is Medicine, chronic disease, and clinical sports
medicine. Further, the number of
presentations devoted to elite sport performance is even smaller. Granted, the word elite implies a very small and select group, be it in reference
to athletes or the sport scientists who study them from basic and applied
perspectives. One of my concerns is
that as many of us veteran sport scientists working with elite/Olympic
athletes move into the final quarter of our careers, this trend toward fewer
and fewer elite sport performance papers/presentations will continue to the
point where we will no longer be seen by the ACSM Program Committee as having
enough impact for inclusion on the annual meeting. As a potential action plan, I offer three
strategies/recommendations: 1. If
you are a sport scientist working at the elite/Olympic level (especially at
the junior level), please make a concerted effort to submit your work for
presentation at the ACSM Annual Meeting. 2. If
you are a senior sport scientist working at the elite/Olympic level, and a
long-time ACSM member, please consider seeking membership on the ACSM Program
Committee, thereby serving as an advocate for elite sport performance
submissions. 3. If
you are a sport scientist working at the elite/Olympic level, please consider
seeking membership on the ACSM Olympic/Paralympic Sports Medicine and Sport
Science Committee. In
closing, I wish to thank Professor Hopkins for the opportunity to review this
report, and I congratulate Louise, Jeni, David and Will on their thorough and
valuable work in disseminating this information to the international sport
science community. Please know that we
appreciate your time and effort. Acknowledgements:
High Performance Sport NZ commissioned a report from WGH. LMB, DTM and JP received
travel grants from their employers. Thanks to the reviewer, Randy Wilber, for
his edits and suggestions.
Published July
2014. ©2014 |