Peri-exercise nutrition: an innovative approach to dietary assessment in trained populations

This thesis offers peri-exercise nutrition (PEN) advancements to dietary assessment for trained populations. The PEN approach promotes time-specific dietary data collection, analysis and prescription, places exercise stimulus as a key consideration of dietary support that is aligned with the goals of trained populations. Engaging the PEN model required advancing data collection and analysis methods. The application of PEN as an advancement to the traditional dietary method of assessment was examined in the context of nutrient support to resistance training (RT) adaptation in a group of trained-individuals, and also nutrient support to endurance exercise adaptation and performance of endurance-trained individuals. Subsequently, traditional and PEN methods were used to apply dietary standardisation to a nutrient-exercise intervention study. Cross-sectional assessment of habitual dietary intake was undertaken on (1) a convenience sample of 37 resistance-trained males (18–40 years) with at least six months of continuous RT experience (RT ≥ 3 h·wk-1 ), and (2) a case study of three endurancetrained males (18–45 years) with VO2max ≥ 55 mlˑmin-1 ˑkg-1 , and participating in competitive endurance events. Traditional dietary analysis demonstrated that, on average, resistance-trained males failed to meet carbohydrate intake recommendations. The PEN analysis revealed that consumption of protein one hour pre-, during RT and one hour pre-bedtime was not common practice. However, though participants consumed [Mdn (25th –75th percentiles)] 5 (4–6) EO post-RT, protein intake per EO was non-optimal in 44% of reported EO (N = 608) post-RT. Overall distribution of EO could be improved in 71% of instances (N = 402) post-RT. The traditional dietary analysis of three endurance-trained males illustrated that daily energy availability and macronutrient intake requirements were met on 0–4 days within a 7-day record. Additionally, the PEN analysis demonstrated that subjects tended to reduce carbohydrate intake before the first endurance training (ET) of the day. Carbohydrate intake recommendations four hours before and during a single competition event were met. In a nutrient-exercise intervention study, a standardised meal plan employing the PEN approach resulted in high compliance to daily quantity of energy and macronutrient intakes [100 (99–100)%], frequency [100 (100–100)%], time and distribution [97 (93–100)%] of EO consumed among resistance-trained males. Informed by the current evidence-base, the PEN assessment in this thesis demonstrates patterns and adequacy of nutrient intakes specific to exercise and intent of trained individuals. Hence, the PEN approach may be a valuable advancement to traditional methods of dietary assessment. Further research is warranted to digitalise data collection and automate analysis of the PEN approach, as well as to consolidate the benefits of this approach in larger cohorts with more complex exercise paradigms.