NutriBar Study
NutriBar, the energy bar distributed by the Meridian International Group, was tested by a crew in the Volvo Ocean Race, in a study into nutritional therapy during an endurance event. From this trial, it was clear that the supplementation with NutriBar during this race diminished the expected loss in the dry-weight lean body mass after leg 1 as well as diminished a fat gain, suggesting health and performance benefits for the crew
Professor Stefan Branth (1) and Maj-Elin Storeide(2)
1. University Hospital of Uppsala, Sweden.
2. Djuice Dragons Racing Team, Norway.
Introduction
The physiological- and mental stress during an offshore sailing race is sometimes extremely hard. The extensive metabolic responses to repeated sessions of sailing 9 legs during 9 months with just a couple of weeks rest in between the different legs are many and very difficult to handle for the sailors and their medical- and nutritional advisers. During the Whitbread (WB) races 93-94 and 97-98 we have made the first comprehensive studies of the physiological-, psychological and medical reactions during this type of repeated stressful conditions (1). The results have in many ways been astonishing. Our results reveal that there is a very high energy turnover, causing catabolic problems and losses of specific nutrients, which has deleterious effects on body composition as well as both mental and physical performance during and after the race. We have also shown that these disturbances will have serious consequences for the overall health of the crewmembers, which might last for a long time. Special nutritional supplement programs can possible partly counteracts these changes. For the first time (WB 97-98) we have, e.g., been able to show that this stress, to fairly well trained healthy non-obese young people, may cause a condition resembling the metabolic syndrome, with e.g. body fat accumulation, blood fat-, urate- and liver enzyme disturbance and amazingly even signs of insulin resistance. In addition, many disturbances in the mineral status and turnover have been noted.
Furthermore, our research from the races 1993-94 and 1997-98 revealed that the Whitbread sailors experienced a state of hypermetabolism, resulting in protein- and energy malnutrition (PEM) with multiple adverse metabolic consequences. PEM of any degree is a strong risk factor for poor quality of life and even increased morbidity and even mortality, including cardiovascular disease (Kalantar-Zadeh K & Kopple JD, 2001). The pathogenesis of these increased health risk factors involves many aspects, including reduced and/or inadequate food intake and metabolic abnormalities similar to stress- and even reactions to severe disease.
Appropriate nutritional therapy is, of course, one important aspect of management of these sailors’ problems, thus their possibility to optimise functions and performances. However, it does not necessarily follow that just providing increased amount of energy during these conditions will improve the outcome. In fact, during these circumstances there is instead a high risk to develop metabolic complications during the course of re-nutrition. That is especially obvious during the rest periods on land and calls for a very careful but active nutritional support both during the hypermetabolic phase during the races as well as during stopovers on land following the catabolic phase. An optimal well-balanced nutritional supplement program is therefore necessary on the boats and during the recovery periods on land.
The impact of nutritional status on physical- and psychological performance is well known. During previous Whitbread races the observed negative energy balance, muscle losses followed by body fat accumulation and micronutrient disturbances have remarkably influenced the performance, both physiologically and mentally. These observations show that there is a need for a top scientific well balanced high energy diet plan, including a well planned intake of essential nutrients, e.g. vitamins, trace elements and fatty acids, both during the race and on shore during the brakes for optimal recovery. Preserving muscle mass during races, avoiding fat store accumulation and repairing cellular disturbances during races and at stopovers are a nutritional and physiological challenge of highest level. Thus the food composition with respect to energy, nutrients, density and balance is of utmost importance together with a well-planned training program on shore. Furthermore, individual taste preferences and variations should also be taken in consideration.
The purpose of this sub-study was to evaluate and discuss possible benefits of an additional nutritional supplement program (NutriBar) applied to the crew of Djuice Dragons racing team after leg one of the Volvo Ocean Race 2001- 2002, since the sailors had been suffering from many adverse catabolic effects during the first leg.
Material and Methods
The crew of Djuice Dragons was studied during leg one, two and four of the 2001-2002 Volvo Ocean Race, an offshore sailing race around the world. The four legs were sailed during approximately five months, and run between Southampton-UK, Cape Town-South Africa, Sidney-Australia, Auckland-New Zealand and Rio de Janeiro-Brazil.
Subjects
The original twelve sailors who participated in the study were all healthy and assumed to be in energy balance before the start of the race, documented by interviews and their stable weight during two months preceding the study. The individual energy needs were determined according to World Health Organisations recommended calculations (FO/WHO/UNU, 1985). After all participants were fully informed of the protocol and received oral and written information, their body composition was measured and blood samples were collected.
During the first four legs the crew received a multi-vitamin-mineral supplement program, mostly according to RDA (Recommended Dietary Allowances, USA). At the stopover in Cape Town after finishing Leg 1, two additional nutritional energy-protein rich Nutrilett powders and one NutriBar “energy-bar” was provided with a mean total composition. To encourage the use of this energy- and protein rich supplement during stopovers it was served as fruit mixed drinks in connection with the breakfast before and after the obligatory training session, four to six days a week. Thus, the aim was that each subject should receive a dosage of approximately 750 ml drink, providing between 500 to 1000 extra kilocalories (kcal) per training day, according to their individual needs and preferable taste and motivation.
Results
All 12 subjects completed the first leg. Two crewmembers were exchanged to other sailors during leg 2, and two additional crew members were replaced during leg 4. The reasons for three crewmember’s exchange after these legs were not of medical origin. One subject was accidental injured during the stopover before leg 4.
Nutritional Intake
During leg 1, the average energy intake was planned to be around 3910 kcal per day and subject. The carbohydrate intake was high and consisted of 63 energy percentage (E%), while the fat E% was 25% and protein E% 12. This composition was substantially changed during leg 2, mainly due to supplementation with special energy and protein rich Nutrilett and NutriBar from Nutri Pharma, leading to mean E% intakes of carbohydrates decreased to 59, fat decreased to 23 and E% protein increased to 18. The average energy intake at the second leg was increased to approximately 5000 kcal per subject and day. At leg 4, the macronutrient relations were kept on the same level while the energy intake was slightly decreased to 4780 kcal.
Body-composition
Total body weight. The mean total body mass (BM, Body weight) decreased 4.0 - 2.0 kg (p < 0.001) during leg 1, while there were no further weight loss recorded after leg 1, after leg 2 and 4 (+0.3 - 2.0 and +0.9 - 3.1, respectively). These stabilised mean weight values were significantly different from the weight loss during leg 1 (Leg 1 vs period 2, p < 0.001; Leg 1 vs period 3, p < 0.01).
Body fat. There was a substantial loss of mean body fat (fat mass, FM) during leg 1, - 2.8 - 2.1 kg FM, p < 0.005, corresponding to – 2.6 - 2.6 % body fat (Fat-%), p < 0.01. The difference between the fat mass loss during leg 1 and the tendency of fat gain during the second period was significant, p < 0.01 for FM and p < 0.05 for Fat-%, respectively. No further significant mean fat mass change (- 0.8 - 2.8 kg FM, ns) was then noted during the last period to the measurement in Rio de Janerio after finishing of Leg 4 (Period 3, 11 weeks from the test at the end of leg 2).
Lean body mass. LBM did not decrease significantly during leg 1 (-1.2 - 2.9 kg LBM, ns). However, thereafter to the test after leg 2 (period 2) there was an additional significant LBM loss of – 1.7 - 1.6 kg, p < 0.01, meaning a total mean LBM loss of –2.8kg, 2 legs from the start. There was not any statistical significant difference between the LBM losses during leg 1 and the second period. During the last period (from to the end of leg 2 to the end of leg 4), no further significant LBM change occurred.
Body water. Total body-water balance showed a significant mean decrease of –1.8 - 2.3L between the tests at the finish of leg 1 and 2 (period 2). During the next period (period 3) to the test after leg 4, most of this ICW loss was normalised by a ICW gain of 1.2 - 1.3 L, p < 0.005 and finally after 4 legs there was no mean total ICW change compared to the start level.
Blood analyzes
Blood haemoglobin and hematocrit were within normal ranges and did not change statistical significant throughout the four tests during the race. Blood fats. Plasma concentrations of total cholesterol, LDL, HDL, LDL/HDL-ratio and triglycerides (TG) decreased significantly during leg 1. Serum total cholesterol concentration went back to the initial level before the start at the test after leg 2 and remained unchanged until the last test after leg 4. The LDL concentration was still statistical significantly (p < 0.05) decreased after 4 legs. The LDL/HDL-ratio remained lowered after 2 legs and went back to the initial start level after leg 4. TG concentration remained, however, increased throughout this study until the test at the finish of leg 4, 5 months from start of the race. Glucose, urate and HbA1c. Plasma glucose and urate concentrations did not change at any point measured during the 5-month race period. Hormones. Serum insulin and C-peptide concentrations after leg 1 and 2 were significantly (p < 0.005) elevated compared to start values. Increased concentrations seemed also to exist after 4 legs, but at that test the elevations were not statistical significant of neither of the two hormones.
Discussion
This report consists of data from 10 subjects from Djuice-Dragons crew. Changes in body composition are one important end-point to assess during metabolic stress. Because there are variations in fluid status during these conditions we consider dry-weight lean body mass as an important determinant for evaluating our nutritional intervention during the various legs. Dry-weight LBM consist to a great extent of muscle proteins. When these are lost, not only muscle strength and performance is impaired, but also the ability of muscle tissue to synthesis and supply e.g. glutamine to the immune system and splanchnic area (liver and gut) is diminished (Neu J et al. 2002). Undoubtedly, this will lead to further physiological disturbances, and ultimately to morbidity (Akner G & Cederholm T, 2001).
High-protein diets have repeatedly shown to minimize losses of lean body mass during dieting, both in conjunction with exercise programs and in sedentary subjects (Rennie MJ et al. 1982; Bennet WM et al. 1989 and 1990). Moreover, it seems like amino acid availability can stimulate muscle protein anabolism in individuals with a reduced muscle mass (Volpi E et al. 1998). However, scientific studies administering high-protein supplements to healthy subjects exposed to intense physical activity and metabolic stress are absent. Important to have in mind is, however, that in this study the total dietary intake changes performed after leg 1, e.g. concerning the protein intake was an increase from an intake of 11-12 Energy% to 18 Energy% of protein with Nutri Pharma products. Since overall energy intake also was improved considerable, the total protein intake was doubled from 112 to 214 grams.
When energy balance is not met, changes in substrate oxidation will follow, and consequently changes in body weight and body composition will occur. Physical activity during energy deficit implies that metabolic processes are focused towards the support of muscle contraction at the expense of events not involved in muscle movement like protein synthesis within the muscle. Many studies have demonstrated the effects of limited energy intake on different organs and functions during single periods. Few studies have studied reactions during repeated periods of energy deficit and the “recovery phases” in between. Moreover, data are extremely limited regarding the role of the composition of nutrients during supplementation under these conditions, e.g. during fairly short periods of “recovery” as during the stopovers in this sailing race. When amino acids and glucose are given together the synthetic rate of muscle protein in young subjects is greater then when amino acids are given alone. Carbohydrate oxidation appears to be better regulated than fat oxidation and is directly dependent on carbohydrate intake. In the study of this crew there were decreased concentrations of the cholesterol parameters, total, LDL and HDL after leg 1 as expected during a period of energy deficit with weight loss. However, these levels returned back to its initial levels already after two legs when NutriBar was given. Knowledge concerning changes in energy turnover and fat oxidation is not as much understood but it seems like there is not any immediately corrective response to increased fat intake (Roy JH et al. 1998). These facts may be one key to the development of the substantial increased fat mass among the sailors noted after two legs. This period included the stopover after leg 1, where there was an imbalanced- and nonoptimal composition of the food intake in most sailors. Moreover, decreased LBM as occurred among the crew will decrease the total BMR and thereby increase the risk of “overeating” with body fat gain as a result. However, no further fat gain was seen after leg 2 while a slight dry weight LBM loss could be noted after leg 4. It is evident that protein intake is the most important determination of whole body protein turnover rates, whereas the intake of energy seems to have little effect. It is also known that the response to increased protein intake occur in two phases. An immediate reaction to the intake of a meal, which results in a depression of whole body protein degradation that is dependent on the amount of protein ingested. During the longer-term adaptation there is also an additional increase of the protein synthesis that also is higher when the diet is high in protein (Garlick PJ et al. 1991). However, little is known about the relative importance of adaptive changes and its time of course. The rates of turnover of tissue protein in humans are generelly very slow. Therefore, changes in tissue protein content or body composition initiated by a change in diet might take long periods to become complete. Additionally the uncompleted knowledge in different substrate utilisation during the type of condition these sailors have lived under with large fluctuating in energy balance might explain the time varying changes in different body compartments.
Reduced food intake and breakdown of body tissue are partly the results of stress activated biochemical and physiological mechanisms, including a system of inflammatory response and neuro-hormonal adaptations, that affect the individual’s appetite, body tissue composition, and ability of the systems to metabolise energy and nutrients. In most cases these pathophysiologic changes are adaptive and homeostatic. Nutritional therapy interacts with the metabolic processes specific to the disorder and under such conditions nutritional therapy must be viewed in a broader medical context. Uncertain adherence/compliance to the supplementation program and the existence of several other concurrent, interacting circumstances and treatments during this course must be taken to consideration and be evaluated. Positive effects can be difficult to detect because of the complexities that exist in nutritional treatments like this. Ability to follow a prescribed nutritional intake varies for example widely. Treatment with nutritional supplements can reduce habitual intake as a result of effects on appetite or abdominal side effects.
Supplementation or enrichment of the diet does however in most studies improve nutrient intake and accordingly performance considerable in conditions resembling the Volvo Ocean Race. However, the resulting average nutritional intake in these sailors showed active improved changes from leg 2. In most of these sailors their behaviour caused by the prolonged stress possibly might have influenced their nutritional intake in an adverse direction, particular concerning energy intake with inappropriate reduced over all nutrient intake during the races and overeating at stopovers which create a situation resembling so called “yo-yo dieting”. The increased fat mass after leg 2 despite 3 weeks sailing is probably due to “over-eating” during the stopover in Cape Town in combination decreased metabolism caused by the situation during leg 1. We could clearly show such “scenario” during the Whitbread Around the World Race during 97-98. Positive is however that no further fat gain was noted in Rio de Janerio after leg 4. This might be due to the new supplementation program. There is also a growing amount of evidence that shows the positive effects on the metabolism of special protein supplements such as NutriBar given at right time under condition like dieting, catabolism and physical training. It is, however, not necessarily the amount but rather the quality and timing that counts under these circumstances. Moreover, the right combination of other macronutrients as well as micronutrients is possibly of outmost importance as well.
When comparing our present data with data obtained during previous Whitbread races, it is clear that the supplementation with Nutri Pharma products during this race diminished the “obligatory” loss in the dry-weight LBM compartment after leg 1 as well as diminished a fat gain, suggesting health and performance benefits for the crew. A substitution of carbohydrate with protein seems to be superior to using a one-sided carbohydrate diet in promoting both satiety of fluctuating energy balance like during these offshore sailing races.
One of the most important factors for muscle growth, or maintenance of muscle mass during stressful conditions, is testosterone. In contrast to previous Whitbread races the crew members in Djuice Dragons Racing Team, did not decrease their testosterone levels after the reaction during leg 1. Instead it was a weak tendency for increased testosterone concentrations after the high protein energy supplement of NutrBar had been administrated. We hypothesise that this can partly explain the maintained dry-weight LBM throughout the remaining race.
Caloric restriction has a unique ability to mobilize a series of adaptive defense mechanisms in the body. Insulin resistance has been suggested as one of these reactions and might partly explain why the sailors showed signs of increased insulin- and HbA1c concentrations throughout the study. The high stress level as well as the trend towards a relative increased fat mass compared to dry-weight LBM is however more likely to be the main reason. These findings calls for more attention since it could be a sign of a medical problem which might develop to a serious chronic condition in the future if repeated several times without taking it under careful consideration and actions. More analyzes and interpreting of the whole material will however be made concerning this important issue.
Glucagon is considered to be the liver´s stress hormone. It is also released by high protein diets. Not surprisingly, it increased throughout the race. Glucagon has the opposite effects to insulin, hence the insulin to glucagon ratio is of interest when estimating the final outcome on metabolism. A low ratio favors glycogenesis, glycolysis (in liver) and lipogenesis, while a high ratio favors glycogenolysis, gluconeogenesis and ketogenesis. The glucagon to insulin ratio decreased to one forth of the initial level during the first leg. After leg 2 and 4 this ratio was only halftened, suggesting that the protein/energy supplementation increased glycogenolysis, gluconeogenesis, ketogenesis and interestingly might have lowered the lipogenesis and thereby leading to decreased fat accumulation. A hypothesis has been proposed concerning different hormonal and neural effects of the protein-carbohydrate ratio of NutriBar that may positively influence the energy turnover rate. Controlled studies indicate that an increase in the protein-carbohydrate ratio of the diet will increase the postprandial glucagon-insulin ratio. The Nutri Pharma protein rich-carbohydrate supplementation after leg 2 might have influenced the hormonal aspects of catabolism and thus e.g. reduced the developments of the metabolic syndrome like reactions seen among these sailors.
Conclusion
The findings in this study are very interesting and it seems like many of the adverse reactions from the first leg when Nutri Pharma products were not given, as well as compared to former Volvo Ocean Sailing Race (Whitbread around the world race) to some degree have been diminished after leg 1 when the Nutri Pharma protein rich supplementation was introduced. Thus additional specific nutritional supplements such as NutriBar high in protein can be suggested to have important positive effects during increased physical activity and metabolic stress situations.
1. University Hospital of Uppsala, Sweden.
2. Djuice Dragons Racing Team, Norway.
Introduction
The physiological- and mental stress during an offshore sailing race is sometimes extremely hard. The extensive metabolic responses to repeated sessions of sailing 9 legs during 9 months with just a couple of weeks rest in between the different legs are many and very difficult to handle for the sailors and their medical- and nutritional advisers. During the Whitbread (WB) races 93-94 and 97-98 we have made the first comprehensive studies of the physiological-, psychological and medical reactions during this type of repeated stressful conditions (1). The results have in many ways been astonishing. Our results reveal that there is a very high energy turnover, causing catabolic problems and losses of specific nutrients, which has deleterious effects on body composition as well as both mental and physical performance during and after the race. We have also shown that these disturbances will have serious consequences for the overall health of the crewmembers, which might last for a long time. Special nutritional supplement programs can possible partly counteracts these changes. For the first time (WB 97-98) we have, e.g., been able to show that this stress, to fairly well trained healthy non-obese young people, may cause a condition resembling the metabolic syndrome, with e.g. body fat accumulation, blood fat-, urate- and liver enzyme disturbance and amazingly even signs of insulin resistance. In addition, many disturbances in the mineral status and turnover have been noted.
Furthermore, our research from the races 1993-94 and 1997-98 revealed that the Whitbread sailors experienced a state of hypermetabolism, resulting in protein- and energy malnutrition (PEM) with multiple adverse metabolic consequences. PEM of any degree is a strong risk factor for poor quality of life and even increased morbidity and even mortality, including cardiovascular disease (Kalantar-Zadeh K & Kopple JD, 2001). The pathogenesis of these increased health risk factors involves many aspects, including reduced and/or inadequate food intake and metabolic abnormalities similar to stress- and even reactions to severe disease.
Appropriate nutritional therapy is, of course, one important aspect of management of these sailors’ problems, thus their possibility to optimise functions and performances. However, it does not necessarily follow that just providing increased amount of energy during these conditions will improve the outcome. In fact, during these circumstances there is instead a high risk to develop metabolic complications during the course of re-nutrition. That is especially obvious during the rest periods on land and calls for a very careful but active nutritional support both during the hypermetabolic phase during the races as well as during stopovers on land following the catabolic phase. An optimal well-balanced nutritional supplement program is therefore necessary on the boats and during the recovery periods on land.
The impact of nutritional status on physical- and psychological performance is well known. During previous Whitbread races the observed negative energy balance, muscle losses followed by body fat accumulation and micronutrient disturbances have remarkably influenced the performance, both physiologically and mentally. These observations show that there is a need for a top scientific well balanced high energy diet plan, including a well planned intake of essential nutrients, e.g. vitamins, trace elements and fatty acids, both during the race and on shore during the brakes for optimal recovery. Preserving muscle mass during races, avoiding fat store accumulation and repairing cellular disturbances during races and at stopovers are a nutritional and physiological challenge of highest level. Thus the food composition with respect to energy, nutrients, density and balance is of utmost importance together with a well-planned training program on shore. Furthermore, individual taste preferences and variations should also be taken in consideration.
The purpose of this sub-study was to evaluate and discuss possible benefits of an additional nutritional supplement program (NutriBar) applied to the crew of Djuice Dragons racing team after leg one of the Volvo Ocean Race 2001- 2002, since the sailors had been suffering from many adverse catabolic effects during the first leg.
Material and Methods
The crew of Djuice Dragons was studied during leg one, two and four of the 2001-2002 Volvo Ocean Race, an offshore sailing race around the world. The four legs were sailed during approximately five months, and run between Southampton-UK, Cape Town-South Africa, Sidney-Australia, Auckland-New Zealand and Rio de Janeiro-Brazil.
Subjects
The original twelve sailors who participated in the study were all healthy and assumed to be in energy balance before the start of the race, documented by interviews and their stable weight during two months preceding the study. The individual energy needs were determined according to World Health Organisations recommended calculations (FO/WHO/UNU, 1985). After all participants were fully informed of the protocol and received oral and written information, their body composition was measured and blood samples were collected.
During the first four legs the crew received a multi-vitamin-mineral supplement program, mostly according to RDA (Recommended Dietary Allowances, USA). At the stopover in Cape Town after finishing Leg 1, two additional nutritional energy-protein rich Nutrilett powders and one NutriBar “energy-bar” was provided with a mean total composition. To encourage the use of this energy- and protein rich supplement during stopovers it was served as fruit mixed drinks in connection with the breakfast before and after the obligatory training session, four to six days a week. Thus, the aim was that each subject should receive a dosage of approximately 750 ml drink, providing between 500 to 1000 extra kilocalories (kcal) per training day, according to their individual needs and preferable taste and motivation.
Results
All 12 subjects completed the first leg. Two crewmembers were exchanged to other sailors during leg 2, and two additional crew members were replaced during leg 4. The reasons for three crewmember’s exchange after these legs were not of medical origin. One subject was accidental injured during the stopover before leg 4.
Nutritional Intake
During leg 1, the average energy intake was planned to be around 3910 kcal per day and subject. The carbohydrate intake was high and consisted of 63 energy percentage (E%), while the fat E% was 25% and protein E% 12. This composition was substantially changed during leg 2, mainly due to supplementation with special energy and protein rich Nutrilett and NutriBar from Nutri Pharma, leading to mean E% intakes of carbohydrates decreased to 59, fat decreased to 23 and E% protein increased to 18. The average energy intake at the second leg was increased to approximately 5000 kcal per subject and day. At leg 4, the macronutrient relations were kept on the same level while the energy intake was slightly decreased to 4780 kcal.
Body-composition
Total body weight. The mean total body mass (BM, Body weight) decreased 4.0 - 2.0 kg (p < 0.001) during leg 1, while there were no further weight loss recorded after leg 1, after leg 2 and 4 (+0.3 - 2.0 and +0.9 - 3.1, respectively). These stabilised mean weight values were significantly different from the weight loss during leg 1 (Leg 1 vs period 2, p < 0.001; Leg 1 vs period 3, p < 0.01).
Body fat. There was a substantial loss of mean body fat (fat mass, FM) during leg 1, - 2.8 - 2.1 kg FM, p < 0.005, corresponding to – 2.6 - 2.6 % body fat (Fat-%), p < 0.01. The difference between the fat mass loss during leg 1 and the tendency of fat gain during the second period was significant, p < 0.01 for FM and p < 0.05 for Fat-%, respectively. No further significant mean fat mass change (- 0.8 - 2.8 kg FM, ns) was then noted during the last period to the measurement in Rio de Janerio after finishing of Leg 4 (Period 3, 11 weeks from the test at the end of leg 2).
Lean body mass. LBM did not decrease significantly during leg 1 (-1.2 - 2.9 kg LBM, ns). However, thereafter to the test after leg 2 (period 2) there was an additional significant LBM loss of – 1.7 - 1.6 kg, p < 0.01, meaning a total mean LBM loss of –2.8kg, 2 legs from the start. There was not any statistical significant difference between the LBM losses during leg 1 and the second period. During the last period (from to the end of leg 2 to the end of leg 4), no further significant LBM change occurred.
Body water. Total body-water balance showed a significant mean decrease of –1.8 - 2.3L between the tests at the finish of leg 1 and 2 (period 2). During the next period (period 3) to the test after leg 4, most of this ICW loss was normalised by a ICW gain of 1.2 - 1.3 L, p < 0.005 and finally after 4 legs there was no mean total ICW change compared to the start level.
Blood analyzes
Blood haemoglobin and hematocrit were within normal ranges and did not change statistical significant throughout the four tests during the race. Blood fats. Plasma concentrations of total cholesterol, LDL, HDL, LDL/HDL-ratio and triglycerides (TG) decreased significantly during leg 1. Serum total cholesterol concentration went back to the initial level before the start at the test after leg 2 and remained unchanged until the last test after leg 4. The LDL concentration was still statistical significantly (p < 0.05) decreased after 4 legs. The LDL/HDL-ratio remained lowered after 2 legs and went back to the initial start level after leg 4. TG concentration remained, however, increased throughout this study until the test at the finish of leg 4, 5 months from start of the race. Glucose, urate and HbA1c. Plasma glucose and urate concentrations did not change at any point measured during the 5-month race period. Hormones. Serum insulin and C-peptide concentrations after leg 1 and 2 were significantly (p < 0.005) elevated compared to start values. Increased concentrations seemed also to exist after 4 legs, but at that test the elevations were not statistical significant of neither of the two hormones.
Discussion
This report consists of data from 10 subjects from Djuice-Dragons crew. Changes in body composition are one important end-point to assess during metabolic stress. Because there are variations in fluid status during these conditions we consider dry-weight lean body mass as an important determinant for evaluating our nutritional intervention during the various legs. Dry-weight LBM consist to a great extent of muscle proteins. When these are lost, not only muscle strength and performance is impaired, but also the ability of muscle tissue to synthesis and supply e.g. glutamine to the immune system and splanchnic area (liver and gut) is diminished (Neu J et al. 2002). Undoubtedly, this will lead to further physiological disturbances, and ultimately to morbidity (Akner G & Cederholm T, 2001).
High-protein diets have repeatedly shown to minimize losses of lean body mass during dieting, both in conjunction with exercise programs and in sedentary subjects (Rennie MJ et al. 1982; Bennet WM et al. 1989 and 1990). Moreover, it seems like amino acid availability can stimulate muscle protein anabolism in individuals with a reduced muscle mass (Volpi E et al. 1998). However, scientific studies administering high-protein supplements to healthy subjects exposed to intense physical activity and metabolic stress are absent. Important to have in mind is, however, that in this study the total dietary intake changes performed after leg 1, e.g. concerning the protein intake was an increase from an intake of 11-12 Energy% to 18 Energy% of protein with Nutri Pharma products. Since overall energy intake also was improved considerable, the total protein intake was doubled from 112 to 214 grams.
When energy balance is not met, changes in substrate oxidation will follow, and consequently changes in body weight and body composition will occur. Physical activity during energy deficit implies that metabolic processes are focused towards the support of muscle contraction at the expense of events not involved in muscle movement like protein synthesis within the muscle. Many studies have demonstrated the effects of limited energy intake on different organs and functions during single periods. Few studies have studied reactions during repeated periods of energy deficit and the “recovery phases” in between. Moreover, data are extremely limited regarding the role of the composition of nutrients during supplementation under these conditions, e.g. during fairly short periods of “recovery” as during the stopovers in this sailing race. When amino acids and glucose are given together the synthetic rate of muscle protein in young subjects is greater then when amino acids are given alone. Carbohydrate oxidation appears to be better regulated than fat oxidation and is directly dependent on carbohydrate intake. In the study of this crew there were decreased concentrations of the cholesterol parameters, total, LDL and HDL after leg 1 as expected during a period of energy deficit with weight loss. However, these levels returned back to its initial levels already after two legs when NutriBar was given. Knowledge concerning changes in energy turnover and fat oxidation is not as much understood but it seems like there is not any immediately corrective response to increased fat intake (Roy JH et al. 1998). These facts may be one key to the development of the substantial increased fat mass among the sailors noted after two legs. This period included the stopover after leg 1, where there was an imbalanced- and nonoptimal composition of the food intake in most sailors. Moreover, decreased LBM as occurred among the crew will decrease the total BMR and thereby increase the risk of “overeating” with body fat gain as a result. However, no further fat gain was seen after leg 2 while a slight dry weight LBM loss could be noted after leg 4. It is evident that protein intake is the most important determination of whole body protein turnover rates, whereas the intake of energy seems to have little effect. It is also known that the response to increased protein intake occur in two phases. An immediate reaction to the intake of a meal, which results in a depression of whole body protein degradation that is dependent on the amount of protein ingested. During the longer-term adaptation there is also an additional increase of the protein synthesis that also is higher when the diet is high in protein (Garlick PJ et al. 1991). However, little is known about the relative importance of adaptive changes and its time of course. The rates of turnover of tissue protein in humans are generelly very slow. Therefore, changes in tissue protein content or body composition initiated by a change in diet might take long periods to become complete. Additionally the uncompleted knowledge in different substrate utilisation during the type of condition these sailors have lived under with large fluctuating in energy balance might explain the time varying changes in different body compartments.
Reduced food intake and breakdown of body tissue are partly the results of stress activated biochemical and physiological mechanisms, including a system of inflammatory response and neuro-hormonal adaptations, that affect the individual’s appetite, body tissue composition, and ability of the systems to metabolise energy and nutrients. In most cases these pathophysiologic changes are adaptive and homeostatic. Nutritional therapy interacts with the metabolic processes specific to the disorder and under such conditions nutritional therapy must be viewed in a broader medical context. Uncertain adherence/compliance to the supplementation program and the existence of several other concurrent, interacting circumstances and treatments during this course must be taken to consideration and be evaluated. Positive effects can be difficult to detect because of the complexities that exist in nutritional treatments like this. Ability to follow a prescribed nutritional intake varies for example widely. Treatment with nutritional supplements can reduce habitual intake as a result of effects on appetite or abdominal side effects.
Supplementation or enrichment of the diet does however in most studies improve nutrient intake and accordingly performance considerable in conditions resembling the Volvo Ocean Race. However, the resulting average nutritional intake in these sailors showed active improved changes from leg 2. In most of these sailors their behaviour caused by the prolonged stress possibly might have influenced their nutritional intake in an adverse direction, particular concerning energy intake with inappropriate reduced over all nutrient intake during the races and overeating at stopovers which create a situation resembling so called “yo-yo dieting”. The increased fat mass after leg 2 despite 3 weeks sailing is probably due to “over-eating” during the stopover in Cape Town in combination decreased metabolism caused by the situation during leg 1. We could clearly show such “scenario” during the Whitbread Around the World Race during 97-98. Positive is however that no further fat gain was noted in Rio de Janerio after leg 4. This might be due to the new supplementation program. There is also a growing amount of evidence that shows the positive effects on the metabolism of special protein supplements such as NutriBar given at right time under condition like dieting, catabolism and physical training. It is, however, not necessarily the amount but rather the quality and timing that counts under these circumstances. Moreover, the right combination of other macronutrients as well as micronutrients is possibly of outmost importance as well.
When comparing our present data with data obtained during previous Whitbread races, it is clear that the supplementation with Nutri Pharma products during this race diminished the “obligatory” loss in the dry-weight LBM compartment after leg 1 as well as diminished a fat gain, suggesting health and performance benefits for the crew. A substitution of carbohydrate with protein seems to be superior to using a one-sided carbohydrate diet in promoting both satiety of fluctuating energy balance like during these offshore sailing races.
One of the most important factors for muscle growth, or maintenance of muscle mass during stressful conditions, is testosterone. In contrast to previous Whitbread races the crew members in Djuice Dragons Racing Team, did not decrease their testosterone levels after the reaction during leg 1. Instead it was a weak tendency for increased testosterone concentrations after the high protein energy supplement of NutrBar had been administrated. We hypothesise that this can partly explain the maintained dry-weight LBM throughout the remaining race.
Caloric restriction has a unique ability to mobilize a series of adaptive defense mechanisms in the body. Insulin resistance has been suggested as one of these reactions and might partly explain why the sailors showed signs of increased insulin- and HbA1c concentrations throughout the study. The high stress level as well as the trend towards a relative increased fat mass compared to dry-weight LBM is however more likely to be the main reason. These findings calls for more attention since it could be a sign of a medical problem which might develop to a serious chronic condition in the future if repeated several times without taking it under careful consideration and actions. More analyzes and interpreting of the whole material will however be made concerning this important issue.
Glucagon is considered to be the liver´s stress hormone. It is also released by high protein diets. Not surprisingly, it increased throughout the race. Glucagon has the opposite effects to insulin, hence the insulin to glucagon ratio is of interest when estimating the final outcome on metabolism. A low ratio favors glycogenesis, glycolysis (in liver) and lipogenesis, while a high ratio favors glycogenolysis, gluconeogenesis and ketogenesis. The glucagon to insulin ratio decreased to one forth of the initial level during the first leg. After leg 2 and 4 this ratio was only halftened, suggesting that the protein/energy supplementation increased glycogenolysis, gluconeogenesis, ketogenesis and interestingly might have lowered the lipogenesis and thereby leading to decreased fat accumulation. A hypothesis has been proposed concerning different hormonal and neural effects of the protein-carbohydrate ratio of NutriBar that may positively influence the energy turnover rate. Controlled studies indicate that an increase in the protein-carbohydrate ratio of the diet will increase the postprandial glucagon-insulin ratio. The Nutri Pharma protein rich-carbohydrate supplementation after leg 2 might have influenced the hormonal aspects of catabolism and thus e.g. reduced the developments of the metabolic syndrome like reactions seen among these sailors.
Conclusion
The findings in this study are very interesting and it seems like many of the adverse reactions from the first leg when Nutri Pharma products were not given, as well as compared to former Volvo Ocean Sailing Race (Whitbread around the world race) to some degree have been diminished after leg 1 when the Nutri Pharma protein rich supplementation was introduced. Thus additional specific nutritional supplements such as NutriBar high in protein can be suggested to have important positive effects during increased physical activity and metabolic stress situations.