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Weight Regulation Strategies In Combat Sports and Their Influence On Anaerobic Power Performance

Weight Regulation Strategies In Combat Sports and

Their Influence On Anaerobic Power Performance

 

Weight regulation strategies aimed at reducing body weight to compete in a lower weight class, enhance performance and improve aesthetics are common practice among athletes competing in a variety of sports (Brownell, Steen, & Wilmore, 1987). Combat sports such as wrestling, boxing, judo and taekwondo all require athletes to compete within specific weight categories for fairer competition as overall body mass and stature can lead to a significant competitive advantage (Alderman, Landers, Carlson, & Scott, 2004; Langan-Evans, Close, & Morton, 2011). This has led to a practice in which athletes compete in a weight category that is up to 10% below their training weight since they believe this will give them a competitive edge over their opponents (Pettersson, Pipping Ekström, & Berg, 2013; Koral & Dosseville, 2009). As a result, athletes and coaches now use various methods to achieve competition weight that can be categorised into rapid weight loss (RWL) strategies through water and sodium depletion, the use of laxatives and diuretics and large caloric reduction and gradual weight loss (GWL) strategies through small caloric reduction (Franchini, Brito, & Artioli, 2012; Fogelholm, 1994).

Weight regulation strategies that involve weight loss (WL) up to 7 days before weight in are considered as rapid whilst those taking longer are considered as gradual (Fogelholm, 1994). The difference in time results in considerably different approaches to achieving target weight. RWL mainly involves dehydration (Lambert & Jones, 2010; Fogelholm, Koskinen, Laakso, Rankinen, & Ruokonen, 1993), whereas GWL involves a gradual reduction in energy intake (Garthe et al., 2011). Research related to weight regulation strategies faces many limitations because athletes in different sports use multiple methods to achieve their target weight (Artioli et al., 2010). These problems are also reflected in the lack of similarities between study protocols and the fact that varying competitive environments make it difficult to establish the effects of WL, especially RWL, on competition performance (Artioli et al., 2010).

The ability to generate power is an important factor for success in many sports including those that impose weight limits in competition (Stone, Pierce, Sands, & Stone, 2006). Power is the product of force and velocity, therefore it directly relates to the athlete’s ability to produce force and the rate at which the force is developed (Stone et al., 2006). Hydration has an important role in sports performance and lean body mass (LBM) plays an important role in energy storage and force production. Due to the fact that athletes reduce body weight rapidly through dehydration or gradually through steady WL, it is important to understand the impact this has on anaerobic power performance (Langan-Evans et al., 2011; Garthe, Raastad, Refsnes, Koivisto, & Sundgot-Borgen, 2011). This highlights the importance for the strength and conditioning (S&C) coach to have a good understanding of weight regulation strategies as this will directly affect how well their athletes perform during training and competition and can also help prevent weight related diseases. Therefore the aim of this article is to look at RWL and GWL methods and provide sound guidelines that athletes can employ to achieve competition weight without compromising their health and negatively impacting their anaerobic power performance.

RWL within a week before competition is most common in combat sports such as wrestling, taekwondo and judo in order for the athlete to achieve competition weight and qualify (Langan-Evans et al., 2011). Athletes also believe that there is a competitive advantage to using RWL since this allows them to drop a weight class and compete against a smaller less powerful opponents without compromising their performance (Artioli et al., 2010). RWL methods in these sports mainly involve WL by eliminating body fluids via severe dieting, fluid restriction, laxatives and even self induced vomiting (Lambert & Jones, 2010; Fogelholm, 1994). This also leads to WL as a result of decreased muscle energy stores and food in the gastrointestinal tract (Horswill, 1992). Most RWL occurs in the days leading up to competition with many athletes reducing body weight in the range of 2-5%, and about 40% of athletes reporting a 5-10% WL and some athletes achieving more than 10% WL (Franchini et al., 2012). These methods usually lead to two common negative health and performance conditions involving malnutrition and dehydration with the latter having more of an acute and even dangerous effect (Oppliger, Utter, Scott, Dick, & Klossner, 2006). Dehydration leads to a decrease in water and electrolytes and restricted energy intake may produce a decrease in LBM and glycogen stores (Brownell et al., 1987). These changes can disrupt the body thermoregulation, cardiovascular function and metabolism and not only impact athletic performance but also the psychological state of the athlete (Pettersson et al., 2013).

There are conflicting reports on the effects of RWL on anaerobic performance, on the contrary aerobic performance is generally shown to decrease. Hoffman, Stavsky and Folk (1995) state that fluid restriction in high intensity moderate duration exercise has a detrimental effect on power performance. Walsh, Noakes, Hawley and Dennis (1994) found that even low levels of dehydration at 1.8% of total body weight could impair high intensity cycling times. These levels however do not seem to effect anaerobic performance. Koral and Dosseville (2009) also reported negative effects on power performance with RWL of 3-4% of total body mass. Casa et al. (2000) suggests that maximal aerobic power shows a decrease in performance only after dehydration is equal to or more than 3% with these decreases exaggerated with extended exercise and hot conditions. Evidence of decreased aerobic performance is mainly attributed to hypohydration, decreased plasma volume, muscle glycogen depletion and impaired thermoregulation (Franchini et al., 2012).

On the other hand, anaerobic performance decline is usually attributed to glycogen depletion, reduction in plasma volume and buffer capacity of the blood (Franchini et al., 2012). According to Horswill (1992) the effects of RWL on anaerobic power and strength are insignificant. The exact mechanisms of why these important characteristics are not compromised are not known but several factors have been proposed to explain this. Muscle concentrations of ATP and phosphocreatine are the main energy sources required in short intense exercise and RWL does not seem to affect these energy sources. Furthermore a decrease in blood flow to the muscle as a result of dehydration is not a limiting factor to the muscle ability to function, because rapid glucose or oxygen transportation is not required during maximal short efforts. It has also been suggested that muscle excitability is not compromised as a result of dehydration and that the nervous system ability to recruit muscle for contraction does not change (Horswill, 1992).

Even so, it is important to note that in combat sports, although short intense efforts requiring anaerobic power are required, sustained or repeated efforts are also needed, along with rapid recovery for success (Franchini et al., 2012). It is also relevant to consider the effects dehydration has on maintaining high intensity power output and muscular endurance as most combat sports events take place over the course of a day and fights can last up to a few minutes (Kraemer et al., 2001). In contrast to brief anaerobic power efforts where muscle glycogen is not required as energy sources, repeated efforts require muscle glycogen, which is shown to decrease as a result of RWL (Kraemer et al., 2001). Moreover, dehydration will cause a decrease in muscle blood flow hindering waste removal, nutrient exchange and heat dissipation (Brownell et al., 1987). This can lead to high levels of lactate that disrupt the acid base balance in the body with each subsequent bout negatively impacting contractile capabilities of the muscle (Kraemer et al., 2001). High lactate concentrations and elevated blood glucose levels due to fluid and nutrient restriction can also cause further depletion of glycogen stores over the course of exercise (Kraemer et al., 2001). These changes will undoubtedly decrease performance and not allow optimal recovery between bouts, since energy levels remain low. This in turn may negatively affect combat sports athletes performances during fights. According to Fogelholm (1994) RWL would typically cause a decrease in anaerobic performance and strength even with 1 to 3 hours of rehydration with performance levels usually returning to normal only after 5 to 24 hours post rehydration. These negative effects have been attributed to hypohydration, glycogen depletion and loss of LBM that can decrease muscle ATP and creatine phosphate concentrations hindering muscular contraction due to insufficient immediate contractile energy sources. Ööpik et al. (1996) found that weight reduction of 5.1-5.8% in two well-trained wrestlers during a 3 day RWL period had a negative effect on maximal power output measured during a single maximal contraction of the quadriceps. The authors also found that isokinetic performance did not return to normal after 16.5 hours recovery period with food and drink ad libitum. This suggests that athletes competing within a 24 hour period from weigh in may not have sufficient time to fully recover muscular contraction function after severe dehydration. Other authors have concluded similarly for other sports. Baker, Dougherty, Chow and Kenney (2007) found that a progressive deterioration in basketball performance as dehydration state progressed from 1% to 4% with 2% as the percentage where there was a significant decrease in performance. Burge, Carey and Payne (1993) found in rowers that dehydration followed by hydration caused a decrease in muscle glycogen utilisation and lowered plasma volume leading to a reduction in maximal rowing performance. According to Langan-Evans et al. (2011) RWL can also have sport specific detrimental effects such as reduction in punching force in boxing and cognitive function. Hall and Lane (2001) found that RWL has detrimental effects on psychological performance in amateur boxers as athletes suffered from increased tension and anger, were quicker to fatigue and had less vigour leading to overall poor performance. Karila et al. (2008) found that RWL reduction has a marked effect on hormonal parameters with significant decreases in serum testosterone and luteinizing hormone concentrations. Haematocrit, haemoglobin and serum creatine markers all increased due to the reduction in weight and dehydration. All these points show that RWL in short periods of time is very likely to hinder performance therefore athletes should be cautious with the percentage of WL they are attempting to achieve.

On the other hand Judelson et al. (2007) looked at the effects of hydration on anaerobic power performance and found that dehydration leading to a loss of 4.8% of total body weight actually did not have a negative effect on vertical jump height, peak lower body power or force however did significantly compromise repeated bouts performance. Lambert and Jones (2010) also found that dehydration of ~3-4% of body weight is not likely to impair maximal muscular power of strength however is certainly going to hinder muscular endurance performance. They also state that dehydration of 2-3% does not impair maximal strength or anaerobic power. This concurs with findings from Fogelholm et al. (1993) that showed no evidence to suggest that weight reduction equal to or less than 5% has a detrimental effect on anaerobic power performance. Storey and Smith (2012) state that passive methods used to reduce body weight seem to have little to no effect on maximal force production or peak power. It seems that rapid rehydration over short period of 2 hours is sufficient to restore neuromuscular performance decreases. The authors highlight that dehydration of 3-4% of total body mass may be more difficult to overcome. Therefore it is recommended that athletes train at no more than 3% above competition weight and use both GWL and moderate dehydration to reach competition weight. Kraemer et al. (2001) looked at how WL techniques affect wrestling performance in tournament setting. The authors found that dehydration and caloric restriction combined with competition place a great deal of stress on the athlete ability to recover. Although the athletes showed very good initial recovery from dehydration WL, their performance declined as the tournament progressed. Whether this can be attributed to just pre-competition preparation is not entirely clear. It is possible that increased rate of glycogen degradation, lactate levels and muscle temperature at muscle tissue levels may cause a decrease in blood perfusion during recovery between contractions. Despite this, athletes showed a good tolerance to losing up to 5% using traditional dehydration methods with no effect on strength performance (Casa et al., 2000). Artioli et al. (2010) found that RWL of 5% of total body weight in cyclist followed by 4 hours of recovery does not affect anaerobic performance and that maximal strength does not seem to be affected. The authors highlight the point that decrements on anaerobic performance usually occur after rapid dehydration and large caloric reduction without an opportunity for the athlete to rehydrate and reefed post weight in. Therefore the period the athlete is allowed to rehydrate plays a critical role in recovery. Research shows that recovery depends on the level of dehydration and the number of hours before competition and that total body WL of 3-5% can be recovered with 3-4 hours (Artioli et al., 2010). Kraemer et al. (2001) suggest that wrestlers might be compromising their peak physical performance as a result of WL via induced dehydration with the percentage loss of total body weight as the determining factor of performance.

Umeda et al. (2004) looked at the effects of GWL and energy restriction in Judo athletes and found that intense exercise combined with energy restriction over a 3 week period has an adverse effect on anaerobic power as well as increasing serum creatine kinase concentration. The authors suggest that this can lead to an increased possibility of muscle tissue injury as a result of impaired muscle function and recommend that WL should not be done using extreme caloric restriction. Lambert and Jones (2010) found that in wrestling specific tasks even GWL strategies can impair performance as a results of ~3.3-6% reduction in weight. This raises an interesting point in that the severity of rather than the speed of the WL may be the main factor in determining performance. Fogelholm et al. (1993) state that the GWL will maintain hydration better, however restricted protein and CHO over long periods of time may decrease LBM and glycogen stores. In contrast, in a study by Garthe et al. (2011) looking at the effects of weekly WL of 0.5Kg over 8 weeks vs. 1Kg over 4 weeks in elite male and female athletes found no changes in 40m sprint performance in both groups. In addition, the 0.5Kg group observed higher performance improvements in all performance tests including 1RM squats, bench press and bench pull. The study found no significant gender differences apart from the 1RM squat in the female athletes. The authors suggest that a more GWL oriented protocol maybe better at preserving or increasing LBM contributing to better performance results. Fogelholm (1994) also found that GWL has no effect on anaerobic performance whilst strength can actually increase. Widerman and Hagan (1982) monitored the preparation of a wrestling athlete for two months leading up to competition day and took measurements at 53, 31 and 3 days prior to competition and found that the subject was able to maintain maximal strength and maximal aerobic power despite a total WL of ~8%. The athlete lost just over 2Kg of LBM however this did not seem to hinder their performance.

In a study looking at differences between GWL vs. RWL in judo athletes, Fogelholm et al. (1993) found no changes in anaerobic Wingate performance and 30m sprint performance throughout the study with GWL having a positive effect on vertical jump performance and no changes in the RWL group. The authors suggest that WL of ~5% by either method can be used by experienced athletes without hindering performance. In a study by Koral and Dosseville (2009) looking at the effects of combined GWL followed by RWL on physical and psychological performance in elite Judo athletes over a 4-week period and 1 day pre competition found that there were no detrimental effects on short duration performance and power. Using GWL athletes can still lose up to 1Kg a week of body weight without compromising their health (Franchini et al., 2012).

It is important when devising a weight regulation strategy to take into account individual consideration of total energy needs, sport and training specific needs and to monitor feedback from training (Burke, Cox, Cummings, & Desbrow, 2001). Fogelholm (1994) recommends that goals should be individualised with time between weight in and competition taken into consideration. While athletes can use RWL to lose 3-5% without hindering anaerobic performance it is important to always highlight the health risks of using such an approach (Franchini et al., 2012). Athletes, especially young and inexperienced, should be discouraged from engaging in RWL methods and coached into more health conscious strategies with GWL taking priority. Lambert and Jones (2010) recommend three important factors for healthy effective WL: a high intensity taper to improve performance after a period of high volume intensity training in euhydration state and a high carbohydrate (CHO) diet. Athletes usually enter a taper phase in the lead to a competition therefore GWL strategies should take into account the decrease in energy expenditure closer to the competition. LBM plays an important role in force production, thus combat athletes who wish to maintain maximum force generation will do best with a diet that will preserve LBM (Langan-Evans et al., 2011). Effective WL strategies should minimise dehydration and LBM losses whilst maximising fat loss (Franchini et al., 2012).

An important factor when considering macronutrient composition is the effects of CHO content in the overall diet. Fogelholm (1994) found that a diet made of 50% CHO or the typical recommendations of 2.5g/Kg/body weight impairs anaerobic performance however a WL strategy that contains CHO of 4g/Kg/body weight seems to sustain performance. These findings concur with research by Burke, Kiens and Ivy (2004) in which CHO recommendations are also advised to remain high. Burke et al. (2004) recommends a high CHO diet of 60-70% and 15-25% of Fat. Lambert and Jones (2010) recommend high CHO diet of 8 to 10g/Kg/body weight/day to help maintain training intensity and performance during competitions. Franchini et al. (2012) also recommends that athletes maintain their CHO consumption as high as possible during WL in order to maintain performance in training, aid recovery and glycogen stores for competitions. The subject in the study by Widerman and Hagan (1982) was able to maintain performance levels across different wrestling tests on a diet composed of 70% CHO. This can be attributed to sufficient muscle glycogen stores and replenishment that protect LBM. This study also highlights the fact that some athletes can follow a GWL strategy and then rapidly dehydrate and still maintain performance. However it is important to stress that athlete experience may have a role in the outcome as more experience athletes might be better at adapting to these physiological changes as they have been through the process several times before. Interestingly, according to Artioli et al. (2010) it is possible that athletes who regularly engage in repeated WL procedures are less prone to its negative effects on performance. Fogelholm et al. (1993) also echo a similar theory and state that repeated cycling of body WL might prevent detrimental effects of RWL. Although there is little evidence to support this, it may be a factor of why more experiences athletes appear to be less affected by RWL strategies. It is important to note that this may be true for experienced athletes with history of weight cycling who can maintain their performance due to developing physiological adaptations however it may not be the case for novice athletes (Artioli et al., 2010).

According to Franchini et al. (2012) athletes who are considering losing more than 5% of their total body mass should rethink their strategy. Fogelholm (1994) recommend body WL of no more than 4% if the time between weigh in and competition is less than 5 hours as short rehydration periods of 1 to 3 hours are not adequate for anaerobic performance recovery. In sports where weigh in and competition time is greater than 5 hours anaerobic power maybe restored to euhydration levels. This also concurs with Franchini et al. (2012) as they state that RWL methods should not be used when athletes have less than 3 hours of recovery as data shows this will be insufficient for rehydration and restoration of glycogen stores. As well consuming high amounts of CHO, fluids and electrolytes, it may also beneficial to consume certain supplements during GWL and post weigh in (Langan-Evans et al., 2011; Franchini et al., 2012). Sodium bicarbonate can be used for intra and inter cellular buffering mechanisms (Kraemer et al., 2001) while BCAA supplement can be used to protect LBM during GWL and low calorie dieting (Franchini et al., 2012).

For athletes in weight category sport there is a constant need to monitor weight and body fat levels, which may develop an unhealthy desire to maintain lower than normal body fat levels (Sundgot-Borgen, 1994). This can lead to poor energy levels and malnutrition and can even result in eating disorders such anorexia nervosa, bulimia nervosa and female athlete triad (Johnson, Powers, & Dick, 1999; Torstveit & Sundgot-Borgen, 2005). Body fat levels of 5% and 12% for male and female athletes respectively should be the minimal for good health and athletes at these levels should not consider WL (Franchini et al., 2012). Johnson et al. (1999) found that female athletes are more likely to suffer from eating disorders and engage in unsafe WL practices however the authors continue to stress the fact that the problem is related to both sexes. Research by Kiningham and Gorenflo (2001) found that American high school wresters continue to engage  in unhealthy WL activities throughout the season with some even putting their health at risk with reckless methods. It is possible to curb reckless RWL methods by educating the coach and athlete and implementing competition changes that make it less advantageous to follow RWL strategies (Franchini et al., 2012). These can involve similar rules that were approved by the National Collegiate Athletic Association and adopted by US wrestling in which body weight and body fat percentage are monitored throughout the season and not allowing wrestlers to compete at below 5% body fat (Gibbs, Pickerman, & Sekiya, 2009). This seemed to have a positive effect as the number of incidents in college wresting decreased but more could be done in international competitions and other sports (Gibbs et al., 2009).

In summary, WL strategies whether rapid or gradual will continue to be used by coaches and athletes unless stricter weight monitoring is introduced and category limits are changed to narrower limits to stop athletes from wanting to compete at lower limits in order to gain competitive advantage. In addition to this, it is also possible to narrow the time between weigh in time and competition in order to minimise the window for recovery to stop athletes from severely dehydrating themselves. Until these changes are implemented it is important for S&C coaches to have their athletes train at only 3% above competition weight and encourage GWL strategies with a diet rich in CHO for training and during competition in order to maintain glycogen stores and recovery. It is also important to limit their athletes to losing no more than 5% of their total body mass weight when using RWL methods before competition and when recovery time is less than 5 hours as WL of more than 5% in short periods of recovery time will not allow the athlete to sufficiently recover. S&C coaches should teach their athletes the correct methods for GWL and consistently monitor their weight and body fat in order to pick up early warning signs of eating disorders.

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