Gary Slater and Lachlan Mitchell
The ability to generate explosive muscle power and strength is critical to success in crossfit, Olympic weightlifting and powerlifting, throwing events including javelin, discus, shot put and hammer, and 100- and 200-metre sprints in track and field. The athletes competing in these events will typically incorporate some form of resistance exercise into their overall training program, as well as diverse sport-specific training. Given the disparity between the sport-specific training programs of strength and power athletes and their subsequent metabolic implications, this chapter will focus on the nutritional implications of resistance training among strength and power athletes. The sport of bodybuilding will also be addressed given the focus on resistance exercise in overall training program prescription.
LEARNING OUTCOMES
Upon completion of this chapter you will be able to:
• understand the training nutrition needs of strength and power athletes, including macronutrient needs over the day
• identify appropriate nutrition strategies to facilitate recovery
• appreciate the issues regarding supplement use in this population
• understand the competition demands of strength and power athletes and translate that into specific nutrition guidance
• appreciate the importance of physique traits among this athlete population and how to manipulate these through dietary interventions.
TRAINING PROGRAMS
Athletics competitors participating in throwing events typically undertake periodised training programs (Chapter 9) that aim to develop maximum strength and power of the major muscle groups. Training involves a range of modalities including plyometric exercises, sprinting, power lifts, Olympic lifts and weighted throwing drills to complement technical throwing training. Periodisation of resistance training typically involves a transition from high-volume, high-force, low-velocity movements requiring less coordination characteristic of traditional powerlifting to more explosive, lower-force, low-repetition training using Olympic lifts in preparation for competition. The focus on explosive Olympic lifts over more traditional strength-based lifting results in more favourable power and strength gains, derived primarily from neural rather than skeletal muscle hypertrophy adaptations. Consequently, this style of training enhances traits important to athletic development and is common among other explosive athletics disciplines like sprinting and jumping events, as well as increasingly being incorporated into the training practices of powerlifters.
Plyometric exercises
Exercises in which muscles exert maximum force in short intervals of time, with the goal of increasing power—for example, jump training.
Explosive
Requiring a maximum or near maximum power output from the athlete in a short amount of time.
Hypertrophy
An increase in skeletal muscle size through growth in size of its cells.
Unlike other sports that use resistance exercise to complement sport-specific training, crossfit, powerlifting, Olympic lifting and bodybuilding use resistance training as a primary mode of training. While Olympic and powerlifting athletes are primarily concerned with enhancing power and strength respectively, bodybuilding training primarily aims to induce skeletal muscle hypertrophy. Consequently, the training programs of bodybuilders are unique, typically of greater volume than those of other athletes, using higher repetition ranges with multiple sets per muscle group and little rest between sets.
TRAINING NUTRITION
Nutrition plays an important role in three aspects of training for strength and power athletes: (1) fuelling of sport-specific and strength training, (2) recovery from this training and (3) the promotion of training adaptations, including skeletal muscle hypertrophy. Resistance exercise requires a high rate of energy supply, derived from both the phosphagen energy systems and glycogenolysis (see Chapter 2) (Lambert & Flynn 2002; Tesch et al. 1986), with the contribution of each dependent upon the relative power output, the work-to-rest ratio and muscle blood flow (Tesch et al. 1986). The source of fatigue during resistance exercise is likely multifactorial, including neuromuscular and peripheral metabolic factors such as decline in intramuscular pH (MacDougall et al. 1999), the latter somewhat dependent on the intensity and volume of training undertaken as well as the time point within a resistance training session. Metabolic fatigue during the earlier part of a workout may be due at least partly to reductions in phosphagen energy system stores and mild acidosis, while subsequent fatigue may result more from acidosis and impaired energy production from glycogenolysis (MacDougall et al. 1999).
Acidosis
A process causing increased acidity in the blood and other body tissue.
Given the extreme muscularity of these individuals and the association between muscle mass and total energy expenditure, it is not surprising that these athletes have generous energy intakes (Slater & Phillips 2011). However, when expressed relative to body mass the energy intakes of strength and power athletes are generally unremarkable relative to those reported for athletes in other sports but lower than current strength athlete guidelines of ~185–210 kJ/kgBM/day (Manore et al. 2000). This likely reflects the fact that taller and/or more muscular individuals have lower resting and total energy requirements relative to body mass. Given this, consideration may need to be given to the allometric scaling of traditional sports nutrition guidelines for macronutrients among larger athletes, reflective of their lower relative energy requirements. Consideration should also be given to distribution of nutrient intake (Thomas et al. 2016), with limited information available on daily distribution of energy and nutrient intake, making it difficult to infer compliance with guidelines relating to key periods of nutrient intake, including before, during and after exercise.
Allometric scaling
Basing an individual’s basal metabolic rate (BMR) and hence requirements on their body mass.
Carbohydrate
A single resistance training session can result in reductions in muscle glycogen stores of as much as 40 per cent (Tesch et al. 1986; MacDougall et al. 1999), with the amount of depletion depending on the duration, intensity and overall work accomplished during the session. Higher repetition, moderate load training characteristic of programming prescribed to promote skeletal muscle hypertrophy results in the greatest reductions in muscle glycogen stores. Reductions in muscle glycogen stores has been associated with performance impairment and, therefore, lower training capacity, although this effect is not always evident and may be dependent on the method used to induce a state of glycogen depletion. Nonetheless, it is possible that impaired training or competition performance could occur in any session or event that relied on rapid and repeated glycogen breakdown.
Given that resistance training is merely one component of the overall training program of sprint and throwing event athletes, and that the skeletal muscle damage that accompanies resistance training impairs muscle glycogen resynthesis, it would seem pertinent to encourage strength trained athletes to maintain a moderate carbohydrate intake. Guidelines proposing an intake within the range of 6 g/kg BM/day for male strength athletes (Lambert & Flynn 2002), and possibly less for females (Volek et al. 2006), have been advocated. Lifters and throwers typically report carbohydrate intakes of 3–5 g/kg BM/day, while bodybuilders maintain daily intakes equivalent to 4–7 g/kg BM/day, independent of gender (Slater & Phillips 2011). While this may appear low relative to endurance athletes, conclusive evidence of benefit from maintaining a habitual high carbohydrate intake among strength athletes remains to be confirmed. Given the lower relative energy expenditure of larger athletes and their requirements for other nutrients, plus the impact of adjusting carbohydrate on total energy intake, recommendations for carbohydrate intake at strategic times, including before, during and after exercise, may be more applicable to the strength athlete, ensuring carbohydrate availability is optimised at critical time points. Thus, we would consider a range of daily carbohydrate intakes of 4–7 g/kg BM as reasonable for these athletes, depending on their phase of training and daily training loads.
Protein
Strength-trained athletes have advocated high-protein diets for many years. While debate continues on the need for additional protein among resistance-trained individuals, general guidelines now recommend athletes undertaking strength training ingest approximately twice the current recommendations for protein of their sedentary counterparts, or as much as 1.2–2.0 g protein/kg BM/day (Phillips & Van Loon 2011). Given the relatively wide distribution of protein in the meal plan and increased energy intake of athletes, it should not be surprising to learn that the majority of strength-trained athletes easily achieve these increased protein needs (Slater & Phillips 2011). Exceeding the upper range of protein intake guidelines offers no further benefit as excess protein is broken down and excreted. Furthermore, there is evidence that an intense period of resistance training reduces protein turnover and improves net protein retention, thus reducing relative dietary protein requirements of experienced resistance-trained athletes.
Simply contrasting an athlete’s current daily protein intake against guidelines does not indicate whether dietary intake has been optimised to promote gains in muscle mass or enhance repair of damaged tissues. Rather, consideration should be given to other dietary factors, including total energy intake, the daily distribution of protein intake (especially as it relates to training), and the source of dietary protein (Morton et al. 2015). While there is very little information available on the eating patterns of strength athletes, available literature suggests the majority of daily protein intake is ingested at main meals from an even mix of animal- and plant-based sources, with a skewed pattern of intake towards the evening meal, indicating a significant proportion of athletes fail to achieve optimal protein intake at breakfast and lunch. Thus, rather than focusing on total daily intake, athletes are encouraged to focus more on optimising protein quality and distribution throughout the day. Given muscle protein synthesis becomes less efficient in response to persistently high levels of amino acids in the blood, it has been suggested 4–5 evenly spaced feedings of ~20 g (0.25 g/kg BM) high biological value protein should be recommended for strength athletes (Phillips & Van Loon 2011).
Fat
The dietary fat intake of strength and power athletes is generally greater than that recommended for healthy individuals and is often derived from sources rich in saturated fat, presumably from an emphasis on animal foods in the pursuit of a higher protein intake. While it is unclear what the impacts of such dietary practices are on athletes’ blood lipid profiles, it may explain in part the lower dietary carbohydrate intakes reported among strength and power athletes. Given that replacing fat with isoenergetic amounts of carbohydrate has a favourable effect on protein balance, it is tempting to recommend a reduction in dietary fat intake, especially for those individuals exceeding current guidelines. However, consideration must be given to the practical implications of substituting a high energy-density macronutrient with a lower energy macronutrient and the impact this may have on energy balance, especially among strength and power athletes with very high energy needs. Conversely, there may be situations in which a higher intake of foods rich in unsaturated fats may be advocated for strength and power athletes struggling to achieve energy needs because of an emphasis on the selection of lower energy-density foods in the meal plan.
Isoenergetic
Containing the same number of calories/kilojoules.
Pre-exercise and during exercise
Athletes are encouraged to pay particular attention to dietary intake in the hours before exercise, on the assumption that pre-exercise nutritional strategies can influence exercise performance. While this is a widely accepted practice prior to endurance exercise to enhance work capacity, evidence is also emerging for a beneficial role of carbohydrate consumed immediately prior to strength training. For example, Lambert at al. (1991) reported that supplemental carbohydrate ingestion prior to and during resistance exercise (1 g/kg before, 0.5 g/kg during) increased total work capacity, a response which has been replicated elsewhere. However, not all studies have shown a benefit from consuming carbohydrate prior to exercise; we propose that the ergogenic potential for carbohydrate ingestion is most likely to be observed when undertaking longer-duration, high-volume resistance training. At present, a specific recommendation for an optimum rate or timing of carbohydrate ingestion for strength and power athletes before and during any given training session cannot be determined. Given the lower relative energy expenditure of resistance exercise to endurance exercise, the lower range of existing exercise carbohydrate intake guidance for endurance athletes (for instance, 1 g/kg before and 0.5 g/kg carbohydrate during exercise) may be a reasonable proxy until more specific resistance training research is undertaken. As with all athletes, strength and power athletes should be encouraged to initiate training in a euhydrated state given that even moderate hypohydration can impair resistance-training work capacity.
Ergogenic
Enhancing physical performance.
Euhydrated
Normal state of body water content.
Hypohydration
Dehydration of the body.
Recently, there has been interest in combining carbohydrate and essential amino acids both before and during resistance exercise, presumably to increase substrate availability and thus exercise performance, to promote a more anabolic (muscle-building) hormonal environment, to stimulate muscle protein synthesis and to reduce muscle damage and soreness. Initial research found that greater muscle protein synthesis occurred when nutritional support was provided before rather than after resistance exercise, but this has not been replicated elsewhere. Consequently, current guidelines recommend that protein be consumed after exercise because this is when there is maximal stimulation of muscle protein synthesis.
Recovery
Given that resistance training typically forms only one component of an athlete’s training schedule, recovery strategies proven to enhance restoration of muscle glycogen stores, such as eating carbohydrate after exercise, should be routinely implemented following resistance training. General sports nutrition guidelines advocate carbohydrate should be consumed at a rate of 1.0–1.2 g/kg BM immediately after exercise. However, this has no influence on muscle protein metabolism. In contrast, consuming protein after exercise results in an exacerbated elevation in muscle protein synthesis at the same time as a minor suppression in muscle protein breakdown, resulting in a positive net protein balance. The ingestion of approximately 20 grams (0.25 g/kg BM) of high biological-value protein after resistance exercise appears to be sufficient to maximally stimulate muscle protein synthesis, with higher doses recommended following resistance-training sessions engaging the whole body and among elderly or injured athletes. So, eating both carbohydrate and protein immediately after resistance training results in more favourable recovery outcomes, including restoration of muscle glycogen stores and muscle protein metabolism, than consuming either nutrient alone. Eating protein after exercise also reduces the amount of carbohydrate required in the acute recovery period, with an energy-matched intake of 0.8 g/kg BM/hour carbohydrate plus 0.4 g/kg BM/hour protein resulting in similar muscle glycogen resynthesis over five hours compared to 1.2 g/kg BM/hour carbohydrate alone following intermittent exercise, with a similar response evident following resistance exercise. Preliminary evidence also suggests that consuming both carbohydrate and protein after exercise may reduce muscle damage often seen in strength-trained athletes; whether such a change has a functional benefit is unclear.
Supplementation practices
Supplement use is reported to be higher among athletes than their sedentary counterparts, with particularly high rates of supplement use among weightlifters and bodybuilders. The high prevalence of supplement use among bodybuilders, Olympic weightlifters, track and field athletes, and those who frequent commercial fitness centres is not unexpected, given the range of products targeted at this market. While multivitamin and mineral supplements are very popular among all athletes, other products such as protein powders and specific amino acid supplements, caffeine and creatine monohydrate are also frequently used by strength-trained athletes.
Recognising the nutritional value of food sources of protein and essential amino acids, creatine monohydrate appears to be the only supplement that has been reported to enhance skeletal muscle hypertrophy and functional capacity in response to resistance training. However, liquid meal supplements rich in carbohydrate and protein may be valuable in the post-exercise period to boost total energy and specific nutrient intake at a time when the appetite is often suppressed. There is also evidence that caffeine enhances muscular strength. While other dietary supplements such as individual amino acids and their metabolites have been advocated for use among bodybuilders, research supporting their ergogenic potential is limited, and thus cannot currently be recommended based on available preliminary literature.
Strength-trained athletes continue to seek supplement information from readily accessible sources, including websites, social media, magazines, fellow athletes and coaches. The accuracy of such information may vary (see the Introduction for more details), leaving the athlete vulnerable to inappropriate and/or ineffective supplementation protocols and an increased risk of inadvertent doping. The presence of muscle dysmorphia, a body dysmorphic disorder characterised by a pre-occupation with a sense of inadequate muscularity common among bodybuilders, may also influence supplementation practices and lead to anabolic steroid use.
Anabolic steroids
Drugs which help the repair and build of muscle tissues, derived from the male hormone testosterone.
COMPETITION
Competition demands of strength sports are typically characterised by explosive single efforts where athletes are given a designated number of opportunities to produce a maximal performance, with significant recovery between each effort. This recovery time means that muscle energy reserves are unlikely to be challenged, even in the face of challenging environmental conditions of competitions like the summer Olympic Games. Consequently, nutrition priorities should focus on more general goals like optimising gastrointestinal tract comfort and preventing weight gain during the competition taper.
Olympic weightlifting, powerlifting and bodybuilding are unique among strength and power sports in that competition is undertaken via weight categories or, on occasion in bodybuilding, by height class. As such, these athletes are likely to engage in acute weight-loss practices common to other weight category sports including short-term restriction of food and fluids, resulting in a state of glycogen depletion and hypohydration. While performance is typically compromised in sports requiring a significant contribution from aerobic and/or anaerobic energy metabolism (Chapter 2), activities demanding high power output and absolute strength are less likely to be influenced by acute weight loss. Furthermore, the weigh-in is typically undertaken two hours prior to the commencement of weightlifting competition, affording athletes an opportunity to recover, at least partially, from any acute weight-loss strategies undertaken prior to the weigh-in. The body mass management guidelines for Olympic combat sport athletes (Reale et al. 2017) would also appear applicable for Olympic weightlifters.
Given the association between lower body-fat levels and competitive success, bodybuilders typically adjust their training and diet several months out from competition in an attempt to decrease body fat while maintaining or increasing muscle mass. While a compromise in muscle mass has been observed when attempting to achieve the extremely low body-fat levels desired for competition, this is not always the case. The performance implications of any skeletal muscle loss are unknown given the subjective nature of bodybuilding competition. Among female bodybuilders such dietary restrictions are often associated with compromised micronutrient intake and menstrual dysfunction, presumably because energy availability falls below the threshold of ~125 kJ/kg fat-free mass/day required to maintain normal endocrine (hormonal) regulation of the menstrual cycle (refer to Chapter 18 for more information).
If muscle protein breakdown is experienced by an Olympic weightlifter or power-lifter as they attempt to ‘make weight’ for competition, a compromise in force-generating capacity, and thus weightlifting performance, is at least theoretically possible. More details on weight category sports and weight-making can be found in Chapter 17.
PHYSIQUE
Within the lifting events, physique traits influence performance in several ways. While the expression of strength has a significant neural component, lifting performance is closely associated with skeletal muscle mass. Excluding the open weight category, weightlifters also tend to have low body-fat levels, enhancing development of strength per unit of body mass. Successful weightlifters also have a higher sitting height-to-stature ratio with shorter limbs, creating a biomechanical advantage. An association between physique traits and competitive success in the Olympic throwing events has been recognised for some time, with successful athletes heavier and taller than their counterparts and growing in size at a rate well in excess of general population trends. In contrast to other strength sports, bodybuilding is unique in that competitive success is judged purely on the basis of the size, symmetry and definition of musculature. Not surprisingly, bodybuilders are the most muscular of all the strength athletes. Successful bodybuilders have lower body fat, yet are taller and heavier with wider skeletal proportions, and are much broader across the shoulders than the hips.
Neural
Relating to a nerve or the nervous system.
While it is reasonable to presume that the nutritional focus of strength and power athletes remains on skeletal muscle hypertrophy throughout the year, in reality this is rarely the case, except perhaps during the ‘off-season’ for bodybuilders or specified times of the annual macrocycle of other strength and power athletes. Furthermore, significant changes in body mass among bodybuilders, Olympic weightlifters and powerlifters will likely influence the weight category they compete in and those they compete against. Thus, the intention to promote skeletal muscle hypertrophy must be given serious consideration by athletes and their coaches before being implemented.
Macrocycle
Refers to the overall training period, usually representing a year.
SUMMARY AND KEY MESSAGES
After reading this chapter, you should have a broad understanding of the important role nutrition plays for athletes competing in sports where the expression of explosive power and strength are critical to competitive success. While total energy intake of strength and power athletes tends to be greater than endurance-focused athletes, intake relative to body mass is often unremarkable, with less known about distribution of nutrient intake over the day. Strength and power athletes will benefit from a greater focus on the strategic timing of nutrient intake before, during and after exercise to assist them in optimising resistance-training work capacity, recovery and body composition. Strength and power athletes create unique challenges for the nutrition service provider given their reliance on readily-accessible sources of information, susceptibility to sports supplement marketing, potentially distorted body image and challenges associated with achieving a specified weight category in some sports plus the general void of scientific investigation in recent years relating specifically to this unique group of athletes.
Key messages
• Strength and power athletes tend to consume more total energy, but less energy relative to their body mass, than endurance-focused athletes.
• Strategic timing of nutrient intake before, during and after exercise will help to optimise training work capacity, recovery and body composition.
• Strength and power athletes are recommended to consume daily carbohydrate intakes of 4–7 g/kg body mass, and daily protein intakes between 1.0 and 1.2 g/kg body mass in the form of 4–5 evenly spaced feedings of ~20 grams (0.25 g/kg body mass) high biological-value protein.
• Athletes should consume carbohydrate at a rate of 1 g/kg before and 0.5 g/kg during training, and focus their protein intake after training during maximal stimulation of muscle protein synthesis.
• Recovery should include consumption of 20 grams of protein (0.25 g/kg body mass) to stimulate muscle protein synthesis, and 0.8 g/kg BM/hour carbohydrate plus 0.4 g/kg BM/hour protein to promote glycogen repletion.
• Athletes’ dietary practices may be influenced by inaccurate nutrition information, sports supplement marketing and distorted body image.
REFERENCES
Lambert, C.P. & Flynn, M.G., 2002, ‘Fatigue during high-intensity intermittent exercise: Application to bodybuilding’, Sports Medicine, vol. 32, no. 8, pp. 511–22.
Lambert, C.P., Flynn, M.G., Boone, J.B.J. et al., 1991, ‘Effects of carbohydrate feeding on multiple-bout resistance exercise’, Journal of Strength and Conditioning Research, vol. 5, no. 4, pp. 192–7.
MacDougall, J.D., Ray, S., Sale, D.G. et al., 1999, ‘Muscle substrate utilization and lactate production during weightlifting’, Canadian Journal of Applied Physiology-Revue Canadienne De Physiologie Appliquee, vol. 24, no. 3, pp. 209–15.
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Reale, R., Slater, G. & Burke, L.M., 2017, ‘Individualised dietary strategies for Olympic combat sports: Acute weight loss, recovery and competition nutrition’, European Journal of Sport Science, vol. 17, no. 6, pp. 727–40.
Slater, G. & Phillips, S.M., 2011, ‘Nutrition guidelines for strength sports: Sprinting, weightlifting, throwing events, and bodybuilding’, Journal of Sports Science, vol. 29, suppl. 1, pp. S67–7.
Tesch, P.A., Colliander, E.B. & Kaiser, P., 1986, ‘Muscle metabolism during intense, heavy-resistance exercise’, European Journal of Applied Physiology & Occupational Physiology, vol. 55, no. 4, pp. 362–6.
Thomas, D.T., Erdman, K.A. & Burke, L.M., 2016, ‘Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance’, Journal of the Academy of Nutrition & Dietetics, vol. 116, no. 3, pp. 501–28.
Volek, J.S., Forsythe, C.E. & Kraemer, W.J., 2006, ‘Nutritional aspects of women strength athletes’, British Journal of Sports Medicine, vol. 40, no. 9, pp. 742–8.