Performance, body composition and wellbeing outcomes in New Zealand multisporters following a ketogenic diet.

This was a case study design of five recreational multisport athletes (four females, one male), with no control control. Athletes were regularly involved in high-level competitive multisport for at least five years undertook a non-calorie-controlled ketogenic diet (<50g carbohydrate; 1.5g protein / kg body weight; remaining calories from fat) for 10 weeks. All participants were non-smokers, healthy and injury-free as per a health screening questionnaire and not consuming a low carbohydrate diet (defined as carbohydrates less than 45% of total energy intake). Prior to the start of the intervention, participants underwent a series of tests and a full consultation for dietary instruction and planning as follows: Performance tests: Participants reported to the lab in the morning in a fasted state and underwent a performance test on three occasions: i. one week prior to the intervention (familiarisation), ii. immediately prior to the intervention (baseline), and iii. immediately post the intervention (post). The performance test was an incremental cycle test using an electromagnetically controlled cycle ergometer to determine VO2peak and gas exchange thresholds (GET) in a temperature-controlled laboratory (21 degrees Celcius, 65 % rH). The test commenced at 30 W and increased by 30 W every 3 minutes until volitional exhaustion. The tests were administered be an experienced exercise physiologist. Body composition measures: Body weight and skinfolds were measured by an ISAK level one accredited anthropometrist, prior to and at the conclusion of the intervention, at the same time of the day. A sum of 8-site skinfold ISAK protocol was applied: triceps, biceps, subscapular, iliac crest, supraspinale, abdominal, front thigh and medial calf. Diet: An initial consultation was conducted with each participant by the primary researcher/Registered Dietitian directly after the performance test. Participants were provided with a daily macronutrient prescription of <50g total carbohydrate, 1.5 g.kg protein and ad libitum fat. A detailed explanation of the practical application of the ketogenic dietary principles along with appropriate tracking and monitoring procedures was provided. Participants were provided with a sample diet and were advised to add variations provided they adhered to the carbohydrate and protein macronutrient thresholds provided. The were instructed to track their diet using a dietary analysis programme Easy Diet Diary (Xyris Software (Australia) Pty Ltd). Diets were monitored weekly by the primary researcher, and participants were contacted and offered additional support if they deviated. The primary researcher maintained regular contact with all participants throughout the 10-week study duration. Interviews and focus group. A 20-30 minute individual interview was conducted on the phone at 5 weeks and a 60-minute focus group was conducted in person once the intervention had concluded.