Abstracts From the December 2018 International Sports and Exercise Nutrition Conference in Newscastle upon Tyne.

Abstract

s From the December 2018 International Sports and Exercise Nutrition Conference in Newscastle upon Tyne Day 1– Orals: Performance Theme Protein Supplementation Does Not Further Augment Physiological Adaptations to Prolonged Endurance Exercise Training KL Jonvik, KJM Paulussen, SL Danen, AMH Horstman, FC Wardenaar, LJC van Loon, and JW van Dijk HAN University of Applied Sciences, Nijmegen, the Netherlands Maastricht University Medical Centre+, Maastricht, the Netherlands FrieslandCampina, Amersfoort, the Netherlands Arizona State University, Phoenix, Arizona, USA It has recently been speculated that protein supplementation may further augment the adaptations to prolonged endurance exercise training. We assessed the impact of protein supplementation during prolonged endurance exercise training on whole-body oxidative capacity (VO2max) and endurance exercise performance. Sixty recreationally active males (age: 27±6 y; BMI: 23.8±2.6 kg·m, VO2max 47±6mL·min ·kg) were subjected to 12 weeks of triweekly endurance exercise training. After each session and each night prior to sleep, participants ingested either a protein supplement (PRO; 29 g casein protein) or an isocaloric carbohydrate placebo (PLA). Before and after the 12 weeks of training, VO2max and endurance exercise performance (∼10-km time-trial) were assessed on a cycle ergometer. Muscular endurance (total workload achieved during 30 reciprocal isokinetic contractions) was assessed by isokinetic dynamometry and body composition by DXA. Dietary intake was assessed at baseline and during the intervention period. Repeated measures ANOVA was applied to assess whether training adaptations were different between groups. Protein intake increased in PRO (1.2±0.4 to 1.6±0.3 g·kg), but not in PLA (1.3±0.4 to 1.2±0.3 g·kg, time x treatment interaction, P<0.001). Endurance exercise training induced an 11±6% increase in VO2max (time effect, P < 0.001), with no differences between groups (PRO: 48±6 to 53±7 mL·min·kg; PLA: 46±5 to 51±6mL·min·kg; time x treatment interaction,P = 0.50). Time to complete the 10-km time-trial was reduced by 14±7% (time effect, P < 0.001), with no differences between groups (time x treatment interaction, P = 0.15). Muscular endurance increased by 6±7% (time effect, P < 0.001), with no differences between groups (time x treatment interaction, P = 0.84). Whole body lean mass was unchanged over time (P = 0.097). However, leg lean mass showed an increase following endurance exercise training (P < 0.001), which tended to be greater in PRO (PRO: 0.5±0.7 kg; PLA: 0.2±0.6 kg; time x treatment interaction, P = 0.073). Protein supplementation after exercise and before sleep does not further augment the gains in whole-body oxidative capacity and endurance exercise performance following prolonged endurance exercise training in healthy, young males. Low Energy Availability Assessed by a Sport-Specific Questionnaire and Clinical Interview Indicative of Bone Health, Endocrine Profile and Cycling Performance in Competitive Male Cyclists N Keay, G Francis, and K Hind Visiting Fellow, Department of Sport and Exercise Sciences, Durham University, UK Science4performance, London, UK Department of Sport and Exercise Sciences, Durham University, UK We evaluated the efficacy of a sport-specific energy availability (EA) questionnaire, combined with clinical interview, for identifying male athletes at risk of developing bone health, endocrine and performance consequences of relative energy deficiency in sports (RED-S). Fifty competitive male road cyclists, recruited through links of participants in a pilot study, were assessed by a newly developed sport-specific questionnaire and clinical interview (SEAQ-I), received dual energy X-ray absorptiometry (DXA) bone mineral density (BMD) and body composition scans and blood tests for endocrine markers. Low EA as assessed using the SEAQ-I, was observed in 28% of cyclists. Low lumbar spine BMD (Z-score < -1.0) was found in 44% of cyclists. EAwas the most significant determinant of lumbar spine BMD Z-score (p < 0.001). Among low EA cyclists, lack of previous load-bearing sport was associated with the lowest BMD (p = 0.013). Low EA was associated with reduced total percentage fat (p<0.019). The 10 cyclists with chronic low EA had lower levels of testosterone compared with those having adequate EA (p = 0.024). Mean vitamin D concentration was below the level recommended for athletes (90 nmol/l). Training loads were positively associated with power-to-weight ratios, assessed as 60 minute Functional Threshold Power (FTP) per kg (p<0.001). Percentage body fat was not significantly linked to cycling performance. This study demonstrates that a sport-specific questionnaire and clinical interview (SEAQ-I) is effective for identifying male road cyclists with acute intermittent and chronic sustained low EA. Cyclists with low EA, particularly in the long-term, displayed adverse quantifiable measures of bone, endocrinology and performance consequences of RED-S. The Impact of a 24-h Low FODMAP Diet on Exercise-Associated Gastrointestinal Symptoms and Breath Hydrogen Responses in Endurance Athletes SK Gaskell, B Taylor, J Muir, and RJS Costa Department of Nutrition Dietetics & Food, Monash University, Australia Department of Gastroenterology, Monash University, Australia Exercise-associated gastrointestinal symptoms (GIS) in endurance athletes are common and can potentially lead to debilitating exercise performances and hampering of post-exercise recovery. This study aimed to determine the impact of preand post-exercise dietary fermentable oligodimonosaccharide and polyol (FODMAP) intake on GIS and breath hydrogen (H2) responses (marker of carbohydrate malabsorption) in response to exertional-heat stress. Using a randomised crossover and counterbalanced study design, non-heat acclimatised recreationally competitive endurance runners (n = 18; male = 10 and female = 8) consumed a 24-h high (HFOD) or low (LFOD) FODMAP diet on one occasion, prior to completing 2-h of running at 60% V̇O2max in hot ambient conditions (35°C, 23% relative humidity). Immediately post-exercise a recovery beverage was consumed matching the 24-h FODMAP diet. GIS and breath H2 samples were collected pre-exercise, every 15 min during exercise, and every 15 min post-exercise for 4-h. Blood samples were collected preand post-exercise S1-1 International Journal of Sport Nutrition and Exercise Metabolism, 2019, 29, S1-1–S1-16 https://doi.org/10.1123/ijsnem.2019-0057 © 2019 Human Kinetics, Inc. CONFERENCE ABSTRACTS to determine plasma osmolality and plasma cortisol concentrations. Participants then repeated the protocol on the alternating diet after a oneweek washout period. The results showed that GIS incidence during exertional-heat stress did not differ between LFOD and HFOD (89%). However, compared with LFOD, the severity of GIS was significantly higher on HFOD preand during exercise, and in total across the day (p = .027, p = .035, and p = .042, respectively). A significant rise in breath H2 (>10 ppm) was evident in HFOD post-exercise from 2:15-h onwards but not on LFOD. A significant difference in total breath H2 production over the 4-h period and the area under the curve was observed on HFOD (mean and 95% CI: 2525 (1452-3597 ppm4-h), peak +17 ppm) compared to LFOD (1505 (1031-1978 ppm4-h), peak +8ppm), (p = .031). Preand post-exercise plasma cortisol did not differ between diets (p > .05). Findings suggest that a 24-h HFOD diet prior to exertional-heat stress, and a HFOD recovery beverage immediately post-exercise, results in exacerbating exercise-associated GIS and carbohydrate malabsorption in comparison to a LFOD dietary intervention. Individual Muscle Hypertrophy to Different Resistance Training Variations: Biological Responsivity vs Training Modulation F Damas, NS Silva-Magosso, TS Chaves, C Barcelos, OC Witard, and CA Libardi Dept of Physical Education, Federal University of São Carlos, Brazil Faculty of Health Sciences and Sport, University of Stirling, Scotland To date, it is unknown if such practice augments intra-individual RTinduced muscle hypertrophy. In this retrospective study, we aimed to examine individualised changes in vastus lateralis cross-sectional area (CSA) to distinct RT variables (ie, frequency, repetition duration and intensity) modulations over an 8-10 wk RT period. A study cohort of 34 young (18-30 y) men from 3 separate data sets each completed a single leg RT programme, ie, each participant completed two RT programmes. Data set A consisted of 10 untrained men who performed 3 sets of leg extension exercise (9-12 max reps) 5x/wk (RT5) vs 3x/wk (RT3) for 8 wk. Data set B consisted of 10 untrained men who performed 3 sets of leg extension exercise (70% 1RM) with a fixed repetition duration (FIX, 2:2s) vs. self-selected tempo (SELF) 2x/wk for 8 wk. Data set C consisted of 14 trained men (RT experience: 5 (3)y) who performed ∼6 sets of leg press + 6 sets of leg extension + 5 sets of leg flexion per RT session (75% 1RM) until muscle failure (RT-F) vs. volitional interruption of each set (RT-V) 2x/wk for 10 wk. Vastus lateralis CSA was measured preand post-RT by ultrasound imaging fitting technique and the change was compared between protocols by paired samples t-tests. Results showed similar (P>0.05) increases in muscle CSA (mean (SD) in cm) for: A, RT5, 2.0 (1.3) and RT3, 2.4 (1.7); B, FIX, 1.0 (0.6) and SELF, 1.3 (0.8); and C) RT-F, 4.2 (3.3) and RT-V, 4.4 (1.7). Intra-subjects analyses revealed that some subjects responded better to one of the protocols (A, RT5: 1, RT3: 5; B, FIX: 1, SELF: 5; C, RT-F: 4, RT-V: 9 subjects) but others showed no differences between legs (A, 4; B, 4; C, 1 subject). Inter-subject variability in the muscle hypertrophic response was high, with the CV varying from 37-77% intra-protocols. These results demonstrate that regardless of RT frequency, repetition duration, intensity manipulation or training status, the individu