Boxing Training: diet and hydration
Making the weigh in
Boxers face a constant battle of maintaining peak condition, while remaining within a strict weight category. But can you maintain optimum performance if you need to lose weight to qualify for your category, especially if ‘making weight’ involves manipulating diet and hydration? James Marshall tries to square the circle…
The danger for boxers and other athletes when trying to ‘make weight’ is that refuelling, rehydration and recovery may be insufficient just at the time when you need to be at your peak. When trying to make weight, boxers may become chronically dehydrated, and in doing so show many of the signs of overtraining (see table 1). This article will look at these signs and symptoms and ways of rehydrating most effectively.
During normal training cycles, boxers undergo overreaching periods, followed by recovery periods in order to improve their fitness. This pattern of overload and rest allows adaptation and is common practice. However, trying to train twice a day is difficult, especially if the evening session has resulted in dehydration. You may wake up the next morning feeling tired and sluggish, and may be tempted not to train, resulting in potentially reduced fitness. On the other hand, by ‘training through’ it, you can compound the effects of fatigue, resulting in poorer performance. As a result, you may try and compensate by working harder only to exacerbate the situation. This is why hydration as part of an overall recovery process that includes refuelling and sleep is important.
Research on boxers is very limited; research on overreaching and overtraining is curtailed by the ethics involved as no coach or athlete deliberately wants to induce overtraining, and so would not allow researchers to induce this. However, looking at other weight category combat sports and their weight loss strategies and also generic research on recovery, we can hypothesise on the best strategies for rehydration.
There is still no single indicator that differentiates between overreaching and overtraining and those that are commonly used, such as heart rate, may not be that accurate (see box 1).
A recent review of the literature on recovery strategies came up with the conclusion that recovery should be an individual process and that the coach and athlete should experiment with what works best for them (6). In fact, the best method to assess if an athlete is overtrained or just suffering from temporary fatigue is for the coach to allow a short break and see if the athlete’s performance improves as a result of this rest. If not, a more in depth assessment will be needed.
Weight loss, dehydration and performance
An acute weight loss of 2% of body weight in a session has been shown to adversely affect performance in all sports (see table 2) (9). Dehydration can result in reduced muscle blood flow, waste removal and heat dissipation, all of which are necessary for sustained, high power muscle action in events such as boxing and judo(10). It can also affect the psychological state of the athlete, leaving them feeling tired and lethargic.
A study using POMS compared the mood states of weight-trained athletes in a hydrated and also a dehydrated state, following a passive dehydration strategy of sitting in a sauna (a common weight loss strategy for weight category sports)(11). Compared to the hydrated state, the athletes in the dehydrated state had a significant drop in systolic blood pressure and vigour. They experienced an increase in POMS measurements of tension, depression, anger, fatigue, confusion and total mood disturbance as well as an increase in hematocrit, specific gravity of urine and haemoglobin (all physiological markers of dehydration).
The researchers used a passive dehydration strategy to prevent the feelings of exercise fatigue from interfering with the findings. These results occurred with only a 1.5% loss of body weight, so it could be assumed that larger losses of weight would result in similar or even more severe changes. These are not the type of effects you want your boxer to experience in the days before his fight!
So if acute weight loss through dehydration is undesirable, what about an 8% weight loss over 22 days? This was the weight loss observed in two Sambo wrestlers who had to make weight before competition (12). By following a low-calorie diet and increasing their training intensity, the wrestlers achieved this significant weight loss. Their isometric strength (important for wrestling) and aerobic power was not affected, but their ability to reproduce anaerobic efforts declined by 13% and their isometric endurance by 7%. This is important to consider when entering a competition with four sets of 2-minute rounds, or when you’re in a tournament such as the Olympics with five or six fights within a 2-week period!
Boxers need to be conscious of rehydration strategies at four key times during their training cycle:
- The normal training routine;
- When trying to make weight;
- Between the weigh-in and the bout;
- In the bout itself.
At each time the rehydration drink and volume will differ because of the different needs. Before looking at these specific points, some general observations on rehydration can be made. A common assumption made is that weight lost during training is all fluid; however, some of this weight loss is from fuels that have been oxidised and water that has been released from stored muscle glycogen.
Attempting to replace this lost fluid/fuel fully during training/competition is difficult and some exercise physiologists such as running guru Professor Tim Noakes have suggested that such drinking strategies can be too aggressive for elite endurance athletes (13). Instead, they recommend a more conservative strategy of intra-session hydration that relies on the individual athlete’s ability to judge what is needed. This often works out at about 500mls of fluid per hour of exercise, depending on factors such as exercise intensity, heat, body weight and mode of exercise.
One hundred per cent fluid replacement during exercise is extremely difficult; if you do try to consume that amount you may experience nausea and you may even be at risk of hyponatremia (water intoxication). However, there is agreement that after exercise you will need to drink about 1.5 litres of fluid for every kilo of weight lost. So, if you lose 2kgs in a session, you should look to consume up to 3 litres of fluid post-exercise.
Sodium or electrolytes
Drinks without sodium have been found to stimulate urine production, meaning that as fast as you put the fluid in, it comes out the other end(14)! This has an impact in rehydration at night time as getting up to go to the loo obviously affects your sleep patterns and disrupts your recovery. Drinking too much fluid in a short space of time also reduces the plasma sodium concentration, which in turn increases urine production. Having sodium as part of the content also helps stimulate the thirst mechanism and encourage the boxer to drink more. A balance has to be struck therefore between sodium content and palatability. If a drink is tasty the boxer will drink more, but if the sodium content is too low, then it just results in more fluid loss through urination.
Although other electrolytes such as potassium and magnesium are often included in sports drinks, the research has not proven their efficacy (15). Such drinks usually contain amounts of potassium that is similar to that found in sweat, the theory being that like replaces like. Commercially available rehydration products from the big supermarket chains and major chemists are very useful for all athletes. Typically theses sachets contain 12mmol of sodium per 200mls of fluid, which is exactly the same percentage as Noakes’ recommendation of 60mmol per litre.
These drinks are designed for use after exercise, not during it, because of the higher sodium content. Compare this with the commercial ‘sports drinks’ that contain about 20mmol of sodium per litre, and have very high levels of glucose in them. This is OK for taste, and maybe for during exercise, but remember that most of their market is aimed at the recreational user and this is how they generate their volumes of sales. It’s also worth adding here that if your post training meal contains sodium, then less sodium can be consumed in the fluids themselves.
Box 2 summarises the general principles of using sports drinks for hydration while box 3 (above) shows how the theory translates into practice for boxers seeking to make weight.
Approaching a big fight is a nervous time for boxer and trainer alike. The goal of reaching peak physical condition has to be balanced with the inevitable performance detriment associated with weight loss when the boxer’s weight exceeds the target. The boxer doesn’t want to go into the fight overtrained, neither does he want to miss sessions or train subpar just because he is dehydrated. By having an effective hydration strategy, boxers can sensibly reduce weight and taper the volume of training at the same time. Traditional methods of weight loss such as road running or saunas will leave the boxer feeling sluggish and out of sorts just when they need to be feeling sharp.
James Marshall MSc, CSCS, ACSM/HFI, runs Excelsior, a sports training company
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