International Society of Sports Nutrition Position Stand: Nutritional recommendations for single-stage ultra-marathon; training and racing

Background. In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~60% of energy intake, 5 – 8 g⸱kg−1·d−1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~1.6 g·kg−1·d−1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g⸱kg−1·d−1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150 - 400 kcal⸱h−1 (carbohydrate, 30 – 50 g⸱h−1; protein, 5 – 10 g⸱h−1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450 – 750 mL⸱h−1 (~150 – 250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., >575 mg·L−1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety

INTER-LIMB ASYMMETRIES, PEAK POWER, AND INTERNAL TRAINING LOADS IN NCAA DIVISION I FEMALE SOCCER ATHLETES

Drake Dillman, Ryan Albino, Caroline Vincenty, Alex Miller, Alexa J. Chandler, Harry P. Cintineo, Bridget A. McFadden, Shawn M. Arent, FACSM. University of South Carolina, Columbia, SC. INTER-LIMB ASYMMETRIES, PEAK POWER, AND INTERNAL TRAINING LOADS IN NCAA DIVISION I FEMALE SOCCER ATHLETES Dillman, D., Albino, R., Vincenty, C., Miller, A., Chandler, A.J., Cintineo, H.P., McFadden, B.A., Arent, S.M. BACKGROUND: Periodic testing and workload monitoring throughout a competitive season can help athletes and coaches periodize training to optimize performance. In particular, vertical jump testing to assess peak power and inter-limb asymmetries can be used to monitor athlete-readiness. The purpose of this study was to evaluate the relationship between internal training loads (TL), asymmetry rates, and peak power throughout a soccer season. METHODS: National Collegiate Athletic Association (NCAA) Division I female soccer players (N=21) were evaluated at all practices and games using a team-based heart rate monitoring system (Firstbeat Sports, Jyvaskyla, Finland) to assess TL via Banister’s training impulse score (TRIMP). At the beginning of each week, athletes performed a dynamic warmup followed by maximal bilateral (CMJ) and single leg (SL) countermovement vertical jump tests using a hands-on-hips method assessed via a digital contact mat. The best of two trials were used for each jump test. An asymmetry index (ASY) was calculated by dividing dominant by non-dominant SL height. A linear mixed effects model was used to assess changes in CMJ, ASY, and TRIMP throughout the season. Repeated measure correlations were used to determine relationships between weekly changes in TRIMP, CMJ and ASY using an absolute ASY score. Significance was set at p\u3c0.05 RESULTS: Time main effects were observed for weekly changes in TRIMP (p\u3c0.001) and CMJ (p=0.01) over the season. No changes in ASY were observed (p=0.09). There was a significant weak correlation between CMJ and ASY (r=0.17; p=0.04), but no other relationships between TRIMP, CMJ, and ASY (p\u3e0.05). CONCLUSION: Changes in internal workloads and peak power were apparent throughout the season and may influence athlete readiness. Although no changes in ASY were seen, a significant inverse correlation between ASY and peak power was observed, which may impact on-field performance. Declines in peak power along with higher asymmetry rates have been associated with injury risk. Systematic monitoring and periodized testing may aid in athlete-management strategies to mitigate these risks

LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report

LGD-4033, a selective androgen receptor modulator, and MK-677, a growth hormone secretagogue, are becoming increasingly used amongst recreationally-active demographics. However, limited data exist describing their effects on health- and androgen-related biomarkers. The purpose of this case study is to report changes in body composition and biomarkers during and after continued co-administration of LGD-4033 and MK-677. We additionally aimed to examine muscular strength and intramuscular androgen-associated biomarkers relative to non-users. A 25-year-old male ingested LGD-4033 [10 mg] and MK-677 [15 mg] daily for 5 weeks. Blood and body composition metrics were obtained pre-, on-, and post-cycle. One repetition maximum (1RM) leg and bench press, as well as intramuscular androgens, and androgen receptor (AR) content were analyzed on-cycle. We observed pre- to on-cycle changes in body composition [BM:Δ+6.0%; LBMtotal:Δ+3.1%; LBMtrunk:Δ+6.6%; LBMappendicular:Δ+4.3%; FMtotal:Δ+15.4%; FMtrunk:Δ+2.8%; FMappendicular:Δ+14.8%], bone [BMC:Δ-3.60%; area:Δ-1.1%; BMD:Δ-2.1%], serum lipid- [cholesterol:Δ+14.8%; triglycerides:Δ+39.2%; LDL-C:Δ+40.0%; HDL-C:Δ-36.4%], liver- [AST:Δ+95.8%; ALT:Δ+205.0%], and androgen- [free testosterone:Δ-85.7%; total testosterone:Δ-62.3%; SHBG:Δ-79.6%] associated biomarkers; however, all variables returned to pre-cycle values post-cycle, aside from FMtotal, FMappendicular, bone area, total cholesterol, and LDL-C. Follicle stimulating hormone (FSH) was below clinical reference values on- [1.2IU/L] and post-cycle [1.3IU/L]. Intramuscular AR [-44.6%], testosterone [+47.8%], and dihydrotestosterone [+34.4%] in addition to 1RM leg press and bench press [+39.2%; +32.0%] were different in the case subject compared to non-users. These data demonstrate LGD-4033 and MK-677 increased several body composition parameters, whilst negatively impacting bone and several serum biomarkers. Given the sparsity of data in recreationally-using demographics, further research is warranted to elucidate the acute and chronic physiological effects of these anabolic agents