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journal of sports sciences 2011 1 11 ifirst article nutrition for power sports middle distance running track cycling rowing canoeing kayaking and swimming 1 2 3 trentstellingwerff ronald j maughan ...

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                Journal of Sports Sciences, 2011; 1–11, iFirst article
                Nutrition for power sports: Middle-distance running, track cycling,
                rowing, canoeing/kayaking, and swimming
                                                   1                                 2                               3
                TRENTSTELLINGWERFF , RONALD J. MAUGHAN , & LOUISE M. BURKE
                1                                              2
                 Nestle´ Research Centre, Lausanne, Switzerland, School of Sport, Exercise and Health Sciences, Loughborough University,
                Loughborough, UK, and 3Department of Sports Nutrition, Australian Institute of Sport, Belconnen, ACT, Australia
                (Accepted 16 May 2011)
                Abstract
                Contemporary training for power sports involves diverse routines that place a wide array of physiological demands on the
                athlete. This requires a multi-faceted nutritional strategy to support both general training needs – tailored to specific training
                phases – as well as the acute demands of competition. Elite power sport athletes have high training intensities and volumes
                for most of the training season, so energy intake must be sufficient to support recovery and adaptation. Low pre-exercise
                muscle glycogen reduces high-intensity performance, so daily carbohydrate intake must be emphasized throughout training
                and competition phases. There is strong evidence to suggest that the timing, type, and amount of protein intake influence
                post-exercise recovery and adaptation. Most power sports feature demanding competition schedules, which require
                aggressive nutritional recovery strategies to optimize muscle glycogen resynthesis. Various power sports have different
                optimum body compositions and body weight requirements, but increasing the power-to-weight ratio during the
                championship season can lead to significant performance benefits for most athletes. Both intra- and extracellular buffering
                agents may enhance performance, but more research is needed to examine the potential long-term impact of buffering agents
                on training adaptation. Interactions between training, desired physiological adaptations, competition, and nutrition require
                an individual approach and should be continuously adjusted and adapted.
                Keywords: Power sports, periodized nutrition, recovery, adaptation, body composition, supplements, performance
                Introduction                                                 result in nutritional challenges that can be best
                                                                             addressed through a periodized nutritional approach.
                While some sports emphasize the exclusive develop-              Only a few previous reviews have focused on the
                mentofstrength or endurance, several sports require          complexities of power sport athletes (Maughan et al.,
                high power output for success. Power is the rate at          1997; Stellingwerff, Boit, & Res, 2007a). The focus
                which work is performed or energy is produced.               of the current article is to outline nutrition recom-
                Most elite power sport athletes can sustain very high        mendationsduringtrainingandcompetition,specific
                power outputs (20 kcal  min71; 500 W) at greater            to power-based athletes involved in events of 1–
                                                              _
                than 100% of maximal oxygen uptake (VO2max),                 10 min duration, including middle-distance run-
   Downloaded by [University of California Santa Cruz] at 16:21 14 October 2011 over races lasting up to 10 min (Table I), whichning, track cycling, rowing, canoeing/kayaking, and
                result in post-exercise blood lactate concentrations in      swimming. In this review, we provide practical
                                       71                                    nutrition recommendations based on modern scien-
                excess of 20 mmol  L     . Accordingly, these athletes      tific  data for acute and chronic training and
                utilize the continuum of energy systems to supply
                adenosine triphosphate (ATP) to meet their energy            competitive situations. We also highlight body
                demands, and are completely reliant upon endogen-            composition considerations and supplements that
                ously stored fuel. To fully develop all energy systems,      are relevant to power athletes.
                elite power athletes undertake a modern periodized
                training approach that features a high volume of
                training during aerobic development and high-                Fuel utilization and energy systems in
                intensity training during the competition phase,             power sports
                coupled with strength training. The demanding
                competition schedules of power athletes and the              A brief overview of energy systems and fuel
                complexities of micro- and macro-training cycles             utilization will set the structure for subsequent
                Correspondence: T. Stellingwerff, Nestle´ Research Centre, PO Box 44, CH-1000 Lausanne, Switzerland. E-mail: trent.stellingwerff@rdls.nestle.com
                ISSN 0264-0414 print/ISSN 1466-447X online  2011 Taylor & Francis
                DOI: 10.1080/02640414.2011.589469
                 2     T. Stellingwerff et al.
                                         Table I. Differences in energy source provision in power-based sporting events.
                                                                                                            %Energy contribution
                                                                                      Approx. %
                                                                                        _
                 Event time range                   Event example                      VO           Phospho      Glycolysis   Oxidative
                                                                                          2max
                 0.5 to 1 min       400-m running; individual cycling time-trial         *150         *10        *47–60        *30–43
                                      (500 m or 1 km); 100-m swimming disciplines
                 1.5 to 2 min       800-m running; 200-m swimming disciplines;         113–130         *5        *29–45        *50–66
                                      500-m canoe/kayak disciplines
                 3 to 5 min         1500-m running; cycling pursuit; 400-m swimming    103–115         *2        *14–28        *70–84
                                      disciplines; 1000-m canoe/kayak disciplines
                 5 to 8 min         3000-m running; 2000-m rowing                       98–102         51        *10–12        *88–90
                 Note: Phospho¼phosphagen breakdown; Glycolysis¼non-oxidative glycolysis (anaerobic metabolism); Oxidative¼oxidative phosphoryla-
                 tion (aerobic metabolism). Data adapted from Spencer and Gastin (2001).
                 nutritional recommendations. Table I outlines the             Nutrition for training
                 approximate fractional energy contribution across a           Periodized nutrition for the yearly training programme
                 range of event lengths for the three energy systems
                 that provide ATP, namely: (1) phosphagen break-               Although the concept of training periodization has
                 down, (2) non-oxidative glycolysis (‘‘anaerobic’’             beenaroundsincethe1950s,theconceptofcoupling
                 glycolysis),  and (3) oxidative       phosphorylation         training with nutrition and body composition period-
                 (‘‘aerobic’’ metabolism). Carbohydrate provides               ization is just starting to gain scientific awareness
                 the majority of the fuel for exercise intensities above       (Stellingwerff et al., 2007a). Periodization is defined
                       _                                                       as the purposeful sequencing of different training
                 75% VO2max, and is a fuel for both non-oxidative
                 glycolysis and oxidative phosphorylation. In con-             units (macro- and micro-training cycles and ses-
                 trast, fat is metabolized exclusively via oxidative           sions), so that athletes can attain the desired
                 phosphorylation. Oxidative phosphorylation pro-               physiological readiness for optimum on-demand
                 vides the bulk of ATP provision during low-intensity          performances (Bompa & Carrera, 2005). Traditional
                 exercise, primarily utilizing Type I muscle fibres.            periodization sequences training into the four main
                 However, during exercise of increasing intensity,             macro-cycles of ‘‘general preparation phase’’, ‘‘spe-
                 when ATP production from oxidative phosphoryla-               cific preparation phase’’, ‘‘competition phase’’, and
                 tion cannot match the rate of ATP hydrolysis, the             ‘‘transition phase’’. However, the training stimuli
                 shortfall in ATP supply is met by substrate level             during these different phases can differ drastically in
                 phosphorylation. This system provides energy via              terms of intensity and volume. Therefore, the types
                 phosphagen utilization and the metabolism of                  of fuels and the amount of energy that are used to
                 muscle glycogen and plasma glucose, via the                   generate the required ATP during these phases need
                 glycolytic pathway, with lactate formation. During            to be addressed through a periodized nutritional
                 moments of high energy demand, there is an                    approach (Table 1; Figure 1). General macronu-
   Downloaded by [University of California Santa Cruz] at 16:21 14 October 2011 increased activation of Type IIa muscle fibres,trientand energy intake recommendations for
                 which have both a high oxidative and glycolytic               athletes when training and in competition are
                 capacity. At very high workloads, Type IIb muscle             covered by Burke and colleagues (Burke, Hawley,
                 fibres become activated to maintain the high                   Wong,&Jeukendrup,2011),Loucksandco-workers
                 demand for ATP provision via glycolysis and                   (Loucks, Kiens, & Wright, 2011), and Phillips and
                 phosphagen breakdown, leading to the extreme                  Van Loon (2011), but further recommendations
                 levels of lactate production associated with many             specific to power athletes will be made in this review.
                 power sport events. Therefore, power athletes have
                 several highly developed energy-producing pathways            General macronutrient and energy intake recommenda-
                 that utilize different blends of phosphagen, carbohy-         tions. During most of the training season, adequate
                 drate, and/or fat, coupled with greater muscle                energy must be consumed to support the training
                 buffering capacity, to handle a range of different            volume and intensity. For example, the training load
                 metabolic demands during varying exercise inten-              of elite swimmers can involve individual swim
                 sities. This understanding of the different energy            practices lasting more than 3 h with over 10,000 m
                 systems and the fuels required to produce ATP                 covered, and daily energy needs are calculated to be
                 must be taken into consideration when making                  about 3000–6800 kcal  day71 for males and about
                 nutrition recommendations.                                    1500–3300 kcal  day71 for females (Van Handel,
                                                                                                         Nutrition for power sports     3
                 Figure 1. Overview of general nutrition recommendations during different yearly training phases for power athletes. Nutrition
                 recommendations for a 70–kg power sport athlete. Prep, preparation; CHO, carbohydrate; FAT, fat; PRO, protein; kcal, nutritional
                 calorie. Adapted from Burke et al. (2001), Tarnopolsky (1999), and Tipton and Wolfe (2004).
                 Cells, Bradley, & Troup, 1984). Manypowerathletes              natural, and due to the diminished or non-existent
                 undertake 9–14 training sessions each week, with               training, energy intake during this phase/day should
                 workouts from about 30 min to 3 h in duration,                 be reduced towards nutritional recommendations
                 including resistance and plyometric/neuromuscular              that are similar to those of the general public
                 training several times per week. Dietary intake studies        (Figure 1).
                 typically find that female athletes report substantially
   Downloaded by [University of California Santa Cruz] at 16:21 14 October 2011 lower energy intake per kilogram of body weightDietary carbohydrate intake recommendations.The
                 (BW) than male athletes: *40 kcal  kg BW71                   seminal paper by Bergstrom and colleagues (Berg-
                 day71forfemalesversus*55kcalkgBW71day71                      strom,Hermansen,Hultman,&Saltin,1967)showed
                 for males (Burke, Cox, Cummings, & Desbrow,                    that a high carbohydrate diet led to augmented
                 2001).Lowerdailyenergyandcarbohydrateintakein                  glycogen stores, translating into a longer time to
                 females may be due to greater under-reporting on               exhaustion than after a low carbohydrate diet. Con-
                 dietary surveys, lower energy/carbohydrate require-            versely, extremely low carbohydrate diets (3–15%
                 ments due to lower training volumes and intensities            carbohydrate) have uniformly been shown to impair
                 than their male counterparts, or a combination of              both high-intensity and endurance-based perfor-
                 these factors.                                                 mance (Coggan & Coyle, 1991; Maughan & Poole,
                   Many athletes aspire to be at competition target             1981). The amount of carbohydrate that is oxidized
                 body weight or body composition year round, which              during exercise depends on both exercise intensity
                 is physiologically and psychologically challenging.            and duration, with carbohydrate oxidation providing
                 During the transition phase, most athletes take a              the majority of ATP when exercising above 75%
                                                                                 _
                 period of rest for both mental and physical recovery           VO2peak. Owing to high exercise intensities during
                 in which training volume and intensity are generally           the specific preparation and competition phases, the
                 very low. Some weight gain during this phase is                relative dependency on carbohydrate-based ATP
                4     T. Stellingwerff et al.
                provision increases throughout yearly training macro-      the protein to increase protein synthesis and optimize
                cyles. However, given the large training volumes           post-exercise recovery.
                during the general preparation phase, the absolute
                requirement for carbohydrate is high, thus carbohy-        Dietary fat intake recommendations. Although the
                drate-rich  foods must provide the majority of             majority of dietary fuel for power sport athletes is
                the energy provision throughout the training year          in the form of carbohydrate, fat also serves many
                (Figure 1).                                                important roles and is a vital fuel source during
                  An examination of dietary studies of power-based         endurance training. Skeletal muscle can store nearly
                sports, albeit usually of sub-elite populations, shows     the energy equivalent of glycogen in the form of
                that male athletes typically report daily carbohydrate     intramuscular triacylglyceride, which is a viable fuel
                intakes averaging approximately 8–9 g  kg BW71           source during prolonged moderate-intensity exercise
                   71                                                                            _
                day   , which is within the recommended range,             up to about 85% VO2max (Stellingwerff et al.,
                while the apparent intake of females is considerably       2007b). The general preparation phase features
                lower at *5.5 g  kg BW71  day71 (Burke et al.,           considerable amounts of endurance training where
                2001). It is absolutely clear that low pre-exercise        endogenous fats are a significant source of fuel
                muscle glycogen concentrations result in reduced           (Figure 1). The amount of dietary fat required for
                high-intensity performance over a cycling test lasting     daily intramuscular triacylglyceride repletion after
                about 5 min (Maughan & Poole, 1981), and that              prolonged (42 h) endurance training has been
                constantly training in an energy and carbohydrate          estimated at 2 g  kg BW71  day71 (Decombaz,
                depleted state may compromise immune function,             2003), while fat intakes greater than this may
                training staleness, and burnout. Therefore, depend-        compromise muscle glycogen recovery and muscle
                ing on individual training volume and intensity, a         tissue repair by displacing the intake of adequate
                habitually high carbohydrate diet of about 6–12 g         amounts of dietary carbohydrate and protein. At
                kg BW71  day71, with females on the lower end             certain times of the year, such as the competition
                and males on the higher end of the range, is               phase, fat intake may be limited to reduce total
                recommended to maintain immune function, re-               energy intake to achieve body composition optimiza-
                cover glycogen storage, and reduce over-reaching           tion. However, throughout all training phases, some
                (Figure 1). Several studies have shown the potential       dietary fat is always needed to aid absorption of fat-
                beneficial effects of training with low/restricted          soluble  vitamins and to provide substrate for
                carbohydrate availability during specific training          hormone synthesis, as well as for cellular membrane
                sessions (reviewed by Burke et al., 2011). However,        and myelin sheath integrity.
                this approach remains controversial in terms of
                performance outcomes, and appears more applicable          Fuelling and fluids during training
                to endurance athletes than power athletes.
                                                                           Since power sport events last only a few minutes,
                Dietary protein intake recommendations. Few studies        there is no opportunity for fuelling (carbohydrate)
                have examined the protein needs of power sport             and fluid intake during competition. However, given
                athletes, as most recommendations have been made           that some training sessions during the general
                for either pure strength- or endurance-trained ath-        preparation phase can approach 2 h in length, there
                letes. However, the daily protein requirement is           is ample opportunity to benefit from carbohydrate
   Downloaded by [University of California Santa Cruz] at 16:21 14 October 2011 probablybasedonthequantityandqualityoftrainingand fluid intake during training. Current recommen-
                rather than the specific sport discipline. During stable    dations for carbohydrate are set to 30–60 g  h71 for
                training periods, protein intake greater than 1.7 g  kg   athletes during exercise, with greater amounts for
                BW71 day71 has been shown to lead to increased            exercise exceeding 2 h. For an overview of current
                protein oxidation. Therefore, it is suggested that elite   recommendations on carbohydrate and fluid intake
                athletes who undertake a large and intense training        during training, see Burke et al. (2011), Jeukendrup
                load will meet their protein requirements with an          (2011), and Shirreffs (2011).
                intake of 1.5–1.7 g  kg BW71  day71 (Figure 1;             Some power sports feature highly technical com-
                Tarnopolsky, 1999). Dietary surveys of westernized         ponents (e.g. swim stroke technique). Consequently,
                athletes have consistently shown that athletes who         carbohydrate intake during training can not only
                consume more than 3000 kcal  day71 most likely            assist in providing energy, but also neuromuscular
                consume protein at or above these levels. However,         support via the attenuation of cognitive fatigue,
                beyond satisfying the current daily protein intake         which can reduce technical errors and enhance skill
                recommendations, emerging evidence strongly sug-           development, as previously demonstrated in team
                gests that the timing, type, and amount of protein         sport models (Currell, Conway, & Jeukendrup,
                consumed over the day, and in relation to exercise         2009). The high intensity of power sport training
                sessions, will have a marked effect on the efficacy of      sometimes prevents the ingestion of carbohydrate
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...Journal of sports sciences ifirst article nutrition for power middle distance running track cycling rowing canoeing kayaking and swimming trentstellingwerff ronald j maughan louise m burke nestle research centre lausanne switzerland school sport exercise health loughborough university uk department australian institute belconnen act australia accepted may abstract contemporary training involves diverse routines that place a wide array physiological demands on the athlete this requires multi faceted nutritional strategy to support both general needs tailored specic phases as well acute competition elite athletes have high intensities volumes most season so energy intake must be sufcient recovery adaptation low pre muscle glycogen reduces intensity performance daily carbohydrate emphasized throughout there is strong evidence suggest timing type amount protein inuence post feature demanding schedules which require aggressive strategies optimize resynthesis various different optimum body c...

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