Current Research in Weight Cutting
The most important factor in weight loss is obviously energy balance i.e. using more calories than you are eating. But how much should you be aiming for per day?
Most of the current research suggests athlete weight loss should be 0.5-1kg (1-2lbs) per week. To achieve this rate of weight loss, an energy deficit of 500-1000 kcal per day is required. This can be achieved by a decrease in energy intake and/or an increase in the energy burnt. The research also provided data to support that even between these two limits (0.5-1kg per week), there can be large differences in the effects upon performance.
They showed that weight loss at a rate of 0.7 per cent bodyweight per week (0.5 kg/1lb for a middleweight boxer) was far superior when compared to 1.4 per cent per cent bodyweight per week (1 kg/2lb for a middleweight boxer) when certain performances were measured. In the group who lost weight at a slower rate, countermovement jump power was increased by 7 per cent whilst no increases were seen in the faster-weight-loss group. Bench pull performance also increased by more when weight was slowly reduced, compared to quickly (10.3 per cent v 4.0 per cent) as did one-rep max for upper-body exercises (11.4 per cent vs. 5.2 per cent).
These parameters provide great support for keeping closer to competition weight and slowly reducing weight as opposed to crashing quickly. Keeping within 5-7 per cent of fight weight would be a good rule of thumb e.g. 132-135lbs for a featherweight boxer or 168-171lbs for a middleweight boxer. This would allow you to drop 0.7 pr cent bodyweight each week over the course of an eight-10-week camp.
Protein is very useful in cutting weight, not only because it helps maintain lean muscle, but it also increases the feeling of fullness (satiety) and the thermogenic effect of food (how many calories are burnt digesting the food eaten).
Increasing protein intake to 2.3-3.1g per kg bodyweight has been shown to help maintain lean muscle mass when compared to lower protein intakes. The leanest sources of protein include skinless chicken, egg whites, white fish, cottage cheese and skimmed milk.
Protein in six evenly spaced servings (every three-four hours) per day is generally accepted as the most effective routine. Recent research has suggested a minimum of 0.3g per kg bodyweight per serving as optimal e.g. for a 57kg (126lb) featherweight fighter 17g per servings and for a 72.5kg (160lb) middleweight fighter 22g per serving.
One paper studied the effects of meal frequency on the role of preservation of lean body mass. Research conducted on elite boxers found that although weight loss was not different between six meals per day or two meals per day when consuming the same amount of calories per day (1200 calories), the group who ate six meals per day maintained a greater amount of lean muscle and lost more body fat that the group who ate two meals per day.
Bone Mineral Density
When reducing weight and also eating a high-protein diet, athletes can often suffer from reduced bone mineral density. This can lead to bones becoming more fragile and possibly an increased chance of injury. However, research has suggested it appears that due to the load-bearing nature of boxing training (i.e. running, weightlifting, sparring), that bone mineral density is maintained. Although bone mineral density does not appear to be reduced, to be on the safe side it would still be recommended to increase calcium and vitamin D intake to help protect bone health as calcium is required for bone formation and vitamin D is required for calcium absorption.
Calcium can be increased by eating a few servings of dairy a day e.g. yoghurts, milk, cottage cheese, but also through leafy green vegetables e.g. broccoli, kale, cabbage and spinach (aim for at least five servings per day). If using a dairy-free diet, calcium supplementation may be required. Vitamin D is harder to get enough of, the only foods vitamin D is found in are oily fish, and this is only in small amounts. 95 per cent of the Vitamin D in our body is produced from exposure to the sun, so in winter many athletes can be deficient.
In preparation for the fight you will be increasing training volume and intensity, often training up to three times per day over the course of the eight-10 week camp. This increase in training can often negatively impact immune function, often seen as an increase in upper respiratory tract infections e.g. colds and sore throats, among other infections. Boxers can also be more at risk of contracting illness due to the nature of boxing, including factors such as increased body contact, bleeding, high sweat-rates for prolonged periods in the humid conditions of gyms and equipment that cannot be washed e.g. boxing gloves.
Research has shown that training in a glycogen-depleted state (very low carbohydrate stores) can also reduce immunity. Athletes training in a glycogendepleted state were shown to have reduced immune systems two hours after training when compared to athletes with high glycogen stores. Research suggests that training with adequate glycogen stores is optimal for maintaining immunity, especially when eating a reduced amount of calories. However, if training in a fasted state or using a very low-carbohydrate diet, always try to consume roughly 50g carbohydrate after intense training to help maintain immunity, but remember to include this intake in your daily calorie intake. If this is a fairly light session then carbohydrates can be withheld and a protein-only recovery snack can be used.
Cutting weight is not rocket science and is basically a matter of using more energy than you are eating and drinking. However, done incorrectly it can be dangerous and/or a real slog. Making the right decisions and eating a varied diet, without cutting out whole food groups, will cover the aspects mentioned above and help make your weight cut or diet a more enjoyable one.
- Eat six servings of protein evenly spaced out three-four hours apart throughout the day and around training.
- These should each contain at least 0.3g per kg protein.
- Eat 500kcal less than you are expending per day; using a calorie tracker can help this.
- Aim to consume 2-3g per kg of carbohydrates, dropping in the final one-two weeks to 1g per kg if required.
- Try not to go over 5-7 per cent over your fight weight.
- Aim for a weight loss of 0.5kg (1lb) or 0.7 per cent bodyweight per week.
- Ensure a good intake of calcium; if lactose intolerant or following a dairy-free diet, increase green leafy vegetables or supplement with calcium.
- Fresh vegetable juices are a great way to consume low-calorie vitamins and minerals. BN
Tom Whitehead is a nutritionist for Soulmatefood. To find out more about what Soulmatefood’s Sportskitchen can do for you go to www.soulmatefood.com.