An investigation into the impact of coaching strategies with respect to physical and performance characteristics of male youth of varying biological maturation

This thesis will be presented as two standalone experimental chapters which will culminate in a thesis discussion linking the two papers under the overarching concept of maturation in male youth. Chapter 2 is currently under review in ‘Cogent Medicine’, and the intention of Chapter 2 is to identify physical, injury and performance-based differences between maturational groups within a general school-based population of 8 youth. These observed differences within Chapter 2 will then inform the methodology and coaching strategies utilised within Chapter 3, which will investigate the effectiveness of various coaching methods in order to maximise adaptation, motor ability and injury prevention within each maturational group. The outcome of this thesis hopes to inform practitioners as to how they can best implement their training programmes to maximise learning and adaptation across a range of biological maturation levels. Rather than just knowing when training should occur which has been investigated previously, it is hoped this thesis will provide insight into how coaching should occur to maximise learning within this diverse adolescent population. Due to the layout of this thesis with the individual papers, there is an element of content repetition throughout Chapters 1,2,3 and 4 which needs to be acknowledged, although the various contexts provides uniqueness throughout

Subjective preferences of varying menthol mouthwash concentrations

Menthol is a widely used, naturally occurring monoterpene alcohol that elicits a feeling of coolness and freshness upon application to the oral cavity, or skin (Stevens & Best, 2016). Recently menthol has demonstrated improvements in time to exhaustion (Mündel & Jones, 2010) and time trial performance (Stevens et al., 2015), but no investigations have been conducted to ascertain the preferred concentration of menthol mouth swill(s)

Menthol mouth rinsing evokes mixed responses in trained runners

Menthol is used to evoke pleasant feelings of coolness and freshness. Sport science has focused upon the topical or oral application of menthol to athletes, either directly on the skin or menthol soaked garments, and as a mouth rinse or in beverages

Perceptual and Physiological Responses to Carbohydrate and Menthol Mouth-Swilling Solutions: A Repeated Measures Cross-Over Preliminary Trial

Carbohydrate and menthol mouth-swilling have been used to enhance exercise performance in the heat. However, these strategies differ in mechanism and subjective experience. Participants (n = 12) sat for 60 min in hot conditions (35 °C; 15 ± 2%) following a 15 min control period, during which the participants undertook three 15 min testing blocks. A randomised swill (carbohydrate; menthol; water) was administered per testing block (one swill every three minutes within each block). Heart rate, tympanic temperature, thermal comfort, thermal sensation and thirst were recorded every three minutes. Data were analysed by ANOVA, with carbohydrate intake controlled for via ANCOVA. Small elevations in heart rate were observed after carbohydrate (ES: 0.22 ± 90% CI: −0.09–0.52) and water swilling (0.26; −0.04–0.54). Menthol showed small improvements in thermal comfort relative to carbohydrate (−0.33; −0.63–0.03) and water (−0.40; from −0.70 to −0.10), and induced moderate reductions in thermal sensation (−0.71; from −1.01 to −0.40 and −0.66; from −0.97 to −0.35, respectively). Menthol reduced thirst by a small to moderate extent. These effects persisted when controlling for dietary carbohydrate intake. Carbohydrate and water may elevate heart rate, whereas menthol elicits small improvements in thermal comfort, moderately improves thermal sensation and may mitigate thirst; these effects persist when dietary carbohydrate intake is controlled for

Changes in pain and nutritional intake modulate ultra-running performance: a case report

Ultra-endurance running provides numerous physiological, psychological, and nutritional challenges to the athlete and supporting practitioners. We describe the changes in physiological status, psychological condition, and nutritional intake over the course of two 100-mile running races, with differing outcomes: non-completion and completion. Athlete perception of pain, freshness, and motivation differed between events, independent of rating of perceived exertion. Our data suggest that the integration of multiple sensations (freshness, motivation, hunger, pain, and thirst) produce performance. Increases in carbohydrate feeding (+5 g·h −1) and protein intake (+0.3 g·kg −1) also likely contributed to successful completion of a 100-mile race, by reducing the fractional utilization of maximal oxygen uptake and satiating hunger, respectively. Nutritional data support the notion that the gut is a trainable, and critical organ with respect to ultra-endurance performance. Finally, we propose future research to investigate the rate at which peak feeding occurs throughout ultra-endurance events, as this may further serve to personalize sports nutrition strategies

The Development of a Menthol Solution for Use during Sport and Exercise

Menthol mouth-swilling has been shown to improve performance across differing exercise modalities, yet no work has been conducted to ascertain the preferred concentration of menthol within a swill. Colour has also been shown to influence psychophysiological outcomes, and may influence the efficacy of ergogenic aids. We conducted two experiments: one to ascertain preferred menthol concentration (0.005–0.105% menthol), the second to assess colour preference (Light Blue, Dark Blue, Light Green, Dark Green, Red). Participants rated swills for Smell, Taste, Freshness, Mouth Feel and Irritation (plus Appearance in the second trial) via 15 cm Visual Analogue Scales (VAS), having swilled and expectorated 25 mL of fluid. Both trials employed a crossover design, with tasting order assigned by Latin squares. Differences were assessed for statistical significance (p < 0.05) using one-way repeated measures ANOVAs. Standardised mean differences ±90% confidence intervals were calculated to assess the magnitude of any observed differences. No significant differences were found between concentrations for total VAS score, but higher concentrations demonstrated a greater number of small effects. Similarly, no significant differences between colours were found. Small effects were found when Light Green was compared to Dark Green and Red. Effects were trivial when Light Green was compared to Light Blue (0.05 ± 0.20) and Dark Blue (0.19 ± 0.32). We recommend athletes employ a Light Green or Light Blue 0.1% menthol mouth-swill

The influence of maturation on functional performance and injury markers in male youth

The aim of this study was to identify the influence of maturation on sprinting and jump performances, whilst quantifying injury markers in 95 youth males (age 13.2–15.7y). Comparative statistics were performed between maturation groups, identifying significant differences (p < 0.05) in all measured anthropometric variables. Sprint and jump performances were positively influenced (ES = trivial to large) by maturation status, whereas injury markers revealed no significant differences between groups. Increases in limb length, muscle size and muscular force output due to corresponding neuromuscular maturation, may help account for these improvements. Individuals’ within the circa PHV group exhibit a larger variability in sprint and jump performance when compared to the pre or post maturation groups. This variability may be attributed to the under-researched phenomenon of “adolescent awkwardness”. To conclude, performance characteristics of youth of similar chronological age vary considerably based on biological maturation, which may have consequences for long-term athlete development

Physiological Responses and Nutritional Intake during a 7-Day Treadmill Running World Record:case report

Ultra-running comprises running events longer than a marathon (>42.2 km). The prolonged duration of ultra-running leads to decrements in most or all physiological parameters and considerable energy expenditure (EE) and energy deficits. SG, 47 years, 162.5 cm, 49 kg, VO2max 4 mL/kg/min−1/2.37 L/min−1, ran continuously for 7 days on a treadmill in 3 h blocks followed by 30 min breaks and slept from 1–5 a.m. Heart rate (HR) oxygen uptake (VO2), rating of perceived exertion, weight, blood lactate (mmol·L−1), haemoglobin (g·dL), haematocrit (%) and glucose (mmol·L−1), and nutrition and hydration were recorded. SG ran for 17.5 h/day, covering ~120 km/day at ~7 km/h. Energy expenditure for each 24 h period was 6878 kcal/day and energy intake (EI) was 2701 kcal/day. EE was 382 kcal/h, with 66.6% from fat and 33.4% from carbohydrate oxidation. 7 day EI was 26,989 kcal and EE was 48,147 kcal, with a total energy deficit (ED) of 21,158 kcal. Average VO2 was 1.2 L·min−1/24.7 mL·kg·min−1, Respriatory echange ratio (RER) 0.80 ± 0.03, HR 120–125 b·min−1. Weight increased from 48.6 to 49.5 kg. Haemoglobin decreased from 13.7 to 11 g·dL and haematocrit decreased from 40% to 33%. SG ran 833.05 km. SG exhibits an enhanced fat metabolism through which she had a large daily ED. Her success can be attributed to a combination of physiological and psychological factors

Physiological responses and nutritional intake during a 7-Day treadmill running world record

Ultra-running comprises running events longer than a marathon (>42.2 km). The prolonged duration of ultra-running leads to decrements in most or all physiological parameters and considerable energy expenditure (EE) and energy deficits. SG, 47 years, 162.5 cm, 49 kg, VO2max 4 mL/kg/min−1/2.37 L/min−1, ran continuously for 7 days on a treadmill in 3 h blocks followed by 30 min breaks and slept from 1–5 a.m. Heart rate (HR) oxygen uptake (VO2), rating of perceived exertion, weight, blood lactate (mmol·L−1), haemoglobin (g·dL), haematocrit (%) and glucose (mmol·L−1), and nutrition and hydration were recorded. SG ran for 17.5 h/day, covering ~120 km/day at ~7 km/h. Energy expenditure for each 24 h period was 6878 kcal/day and energy intake (EI) was 2701 kcal/day. EE was 382 kcal/h, with 66.6% from fat and 33.4% from carbohydrate oxidation. 7 day EI was 26,989 kcal and EE was 48,147 kcal, with a total energy deficit (ED) of 21,158 kcal. Average VO2 was 1.2 L·min−1/24.7 mL·kg·min−1, Respriatory echange ratio (RER) 0.80 ± 0.03, HR 120–125 b·min−1. Weight increased from 48.6 to 49.5 kg. Haemoglobin decreased from 13.7 to 11 g·dL and haematocrit decreased from 40% to 33%. SG ran 833.05 km. SG exhibits an enhanced fat metabolism through which she had a large daily ED. Her success can be attributed to a combination of physiological and psychological factors