Continued investigation of the effect of low energy availability and low carbohydrate availability on hormone status, metabolism and performance in elite race walkers ('Supernova 5")

Parallel Group design with elite race walkers allocated, according to their preference, to an intervention of short term (5-6 d) exposure to and reversal of: • Low Energy Availability (LEA: ~15 kcal/kg fat free mass/day, with ideal protein intake to the other diets but reduced carbohydrate and fat intake) • High Energy/Carbohydrate Availability (Control: ~40 kcal/kg fat-free mass/day; 65% of energy from carbohydrates, ~15% from energy fats, and 2.1g/kg/d protein) • High Energy/Low Carbohydrate Availability eating (LCHF: 75-80% of energy from fats, <50g/d carbohydrates and 2.1g/kg/d protein) Detailed methodology: The Supernova 5 Research camp will be held over a ~4 week period from January 1-February 2, with final information being collected from the 20 km National Race Walking Championships in Adelaide on February 9. Supernova 5 Research camp will be held at the AIS Canberra campus and will involve live-in accommodation in the AIS Residences in which the dietary interventions and training program will be controlled and monitored. Study funding will support the accommodation, meals and training resources needed to implement the study design. A professional chef will provide all meals to ensure that it is an enjoyable experience, and menus will be personalised to the requirements and special needs/preferences of the athletes. We anticipate that most of the participants will have been involved in previous Supernova Research camps and value both the training camp experience/benefits and the embedded research. Study phases. Phase 1 (Screening): On entry to the Supernova 5 camp, we will undertake screening tests to identify baseline characteristics around aerobic capacity, performance and pre-existing markers of energy availability. This will allow us to identify participants who should be excluded from the study due to frank markers of LEA (e.g. consistency in results of low RMR and low fasting hormone concentrations), and to finalise the allocation of athletes into treatment groups based on intervention preferences and matching of key baseline characteristics. Screening tests will involve • VO2max and economy test according to Supernova 4 • DXA assessment of body composition and bone mineral density • Measurement of Resting Metabolic Rate • Screen for fasting concentrations of key hormones (testosterone, estrogen, IGF-1, insulin and T3) to screen for LEA Baseline + Test Block 1 The commencement of Test Block 1 will be undertaken with the support of a diet with high availability of energy (40 kcal/kg FFM/d) and carbohydrate (65% of energy: 8-10 g/kg/d) Tests will involve • VO2max and economy test according to previous Supernova protocols (key change = test to be undertaken after a standardized meal rather than in fasted state) • For the LCHF group: an additional test session will involve the intake of a ketone ester supplement (HVMN: batch tested commercial supplement with recommended dose of 1 bottle) 60 min prior to a repeat of the economy test (4 stages) to characterise any differences in metabolism due to the supplement • 10,000 m race walking event conducted by ACT athletics and sanctioned by IAAF (Race 1). This race will be preceded by 24 h of standardised high-carbohydrate, high-energy availability eating, and a high carbohydrate pre-race meal Harmonisation diet + Completion of Test Block 1: All participants will be supervised to consume a diet providing high energy availability and high carbohydrate availability to support a structured training program, which will consist of several standardised training sessions (long walk. Hills session, rep session) and sessions of the athlete’s own choosing. This phase will be conducted for 5 d, with the goal of achieving full energy availability for each participant for the completion of Test Block 1. This diet will be continued throughout Test Block 1, and on completion of the testing, participants will then commence their dietary intervention. Block 1 testing will consist of • DXA/RMR • 25 km long walk test • Overnight hormone pulsatility (LH, cortisol and Growth Hormone) • Fasting metabolic and reproductive hormones (testosterone, estrogen, IGF-1, insulin and T3) Phase 2 (Intervention) Participants will be supervised to consume one of three personalised diets (as detailed above). Participants will continue to consume these diets for the commencement of Block 2 testing. Test Block 2 will repeat the tests involved in Block 1: • VO2max/economy test (to profile metabolism over a range of exercise intensities as a result of the dietary treatments) • For the LCHF group: an additional test session will repeat the intake of a ketone ester supplement (HVMN: batch tested commercial supplement with recommended dose of 1 bottle) 60 min prior to a repeat of the economy test (4 stages) to characterise any changes in metabolism due to the supplement following adaptation to a ketogenic diet • DXA/RMR • 25 km long walk test • Overnight hormone pulsatility (LH, cortisol and Growth Hormone) • Fasting metabolic and reproductive hormones (testosterone, estrogen, IGF-1, insulin and T3) • Race 2. Race 2 will involve the same protocol as Race 1, with o LEA subjects resuming 24 h of standardised high-carbohydrate, high-energy availability eating and a high carbohydrate pre-race meal. This will allow us to confirm the findings of Supernova 4 that the potential performance disadvantages of the intervention diets can be overturned by 24 h of restored energy/carbohydrate availability. Indeed, there may be net benefits due to loss of BM or enhanced fat oxidation in concert with restored fuel status. o LCHF subjects will remain on the LCHF diet and will consume a bottle of the ketone ester supplement to investigate the benefits of this supplement on higher intensity endurance performance Phase 3 (Refeeding) In this phase, all participants will resume 5 d of high energy/high carbohydrate diet (i.e. the Control HCHO diet) to fully restore fuel availability before departing the camp. The final test will involve a recheck of the restoration of any hormonal perturbations due to the intervention diets • Fasting metabolic and reproductive hormones (testosterone, estrogen, IGF-1, insulin and T3) Post-camp It is anticipated that most participants will race in the 2020 Australian Road Racing 20 km championships in Adelaide on February 9. Participants will be invited to record their self-chosen dietary intake and training in preparation for this race. Researchers will provide support for participants during the race (feeding from aid stations) and record race behaviours (fluid intake, carbohydrate intake, BM changes) and outcomes to provide feedback about the achievement of their self-chosen race nutrition goals. This will form descriptive information on practices of elite endurance athletes during race conditions, and provide opportunity for insight into the effect of the camp involvement on race performance