White, Christopher (University of Chester, 2014-10)
In 2007 it was announced by Cycling England that Chester was to become a Cycling Demonstration Town (Cycling England, 2010). Rather than the typical English local authority spend on cycling promotion, this meant that Chester would receive a sum of money similar to seemingly pro-cycling cities, such as Amsterdam (DfT, 2008). However there is yet to be an official evaluation of the second round of Cycling Demonstration Towns. This thesis is designed to demonstrate the context of delivering parties in one specific case-study, the Cycling Demonstration Towns Project ‘Cycle Chester’. Fifteen semi-structured interviews explored the views and experiences of various different concerned actors, both inside and outside the core delivery group. The concepts of figurational sociology have been employed to help understand the findings. The principal finding was that the complex figuration in which deliverers were situated meant that the project encountered several unintended outcomes. In addition to this, two key areas were found to have the potential to further complicate the delivery process. Firstly the way in which potential towns and cities were encouraged to apply for funding was found to have large impacts on the project at a later stage. Secondly, and perhaps most importantly, the differing goals of the many groups and individuals who were eventually involved with the project meant that interventions were often ‘watered-down’.
Unaccustomed eccentric exercise commonly induces the immediate and prolonged symptoms of exercise-induced muscle damage (EIMD). Whilst an initial bout impairs sub maximal endurance performance, a repeated bout of the same eccentric exercise attenuates symptoms of EIMD. This is known as the repeated bout effect (RBE). Furthermore, it is claimed that training the unilateral limb, increases the strength of the contralateral homologous limb. This is manifested through neural adaptations and is known as cross-transfer. Accordingly, this study investigated if an initial bout of eccentric exercise in the unilateral leg would provide protection from the detrimental effects of EIMD on endurance performance after a second bout of eccentric exercise in the contralateral leg. After institutional ethical approval, 12 healthy, recreational participants were randomly assigned to two groups (ipsilateral, n = 6 both bouts performed in the same leg; contralateral, n = 6 one bout performed in each leg) who performed 10 x 10 eccentric contractions. Strength, perceived soreness and sub maximal cycling exercise was measured at baseline, 24 h and 48 h. Two weeks later, when symptoms of EIMD had dissipated, all procedures were repeated. Results revealed that perceived muscle soreness and isometric strength (P < 0.05) were significantly altered following the eccentric exercise at 24-48 h after an initial bout of EIMD. However, after a repeated bout, the symptoms of EIMD were attenuated in both the ipsilateral and contralateral groups. Furthermore, this had no significant effect on sub maximal endurance cycling. EMG data provided evidence for RBE after decreases in MF and increases in peak amplitude. This data further supports the evidence for a RBE, and supports observations that protective adaptations transfer to the untrained limb. EMG data supports this neural adaptation.
L-arginine is one of the most metabolically versatile amino acids in the human body, most notably serving as the pre-cursor for the biosynthesis of nitric oxide (NO). The reported physiological effects of L-arginine have served as the rationale behind the development and marketing of a number of NO stimulating dietary supplements, which profess to augment NO production and improve blood flow to muscle during exercise. Supplementation with L-arginine and similar “NO boosters” has soared in popularity over the last decade, despite the fact that there is an overall lack of supportive data in healthy humans, as ergogenic potential remains inconclusive. The aim of this study was therefore to determine the effects of acute supplementation of commercially available L-arginine on exercise performance. Twelve recreationally trained, young adult males (22.3 ± 4.1 yr, 79.3 ± 7.9 kg, 180.9 ± 2.3 cm) consumed either: a placebo (PLA), an L-arginine beverage containing 8g L-arginine (ARG) or no beverage (CON) in a double-blind, repeated-measures design. 45 minutes following consumption, participants completed a 10 mile time trial on a cycle ergometer. There was no significant difference (p=0.643) in time-trial performance between the conditions (CON 29:49 ± 2:19 vs ARG 29:49 ± 3:18 vs PLA 29:30 ± 2:42 minutes). There was no significant difference (p=0.276) between conditions in volitional power output (W) (CON 119.3 ± 8.7 vs ARG 120.1 ± 7.7 vs PLA 121.2 ± 6.2 W), or in heart rate responses (p=0.129) (CON 169.2 ± 11.3 vs ARG 167.2 ± 10.8 vs PLA 166.3 ± 7.8 bpm). Significant differences (p=0.033) were observed between conditions (CON 15.6 ± 1.6 vs ARG 15.2 ± 2.0 vs PLA 15.0 ± 1.7) in RPE responses. With no ergogenic benefits observed in this study, the rationale for pre-exercise supplementation with arginine may be further brought into question.
With recent advancements in technology, fully-immersive virtual reality (VR) is now fast emerging as the latest piece of equipment that may revolutionise the way in which athletes are able to train. However, as of yet, few have examined the perceptual and physiological responses to exercising in VR and the subsequent impact it may have on performance. Using a repeated measures randomised crossover design, thirteen recreationally active participants (age = 24.9 ± 4.6 y; body mass = 78.7 ± 6.3 kg; stature = 178.6 ± 3.7 cm; VO2max = 55.1 ± 7.1 ml·kg-1·min-1, P-VO2 =344.7 ± 49.7) completed a time to exhaustion test (TTE) at 80% of P-VO2 under a control (CON) and virtual reality (VR) condition, with a minimum of 48h between trials. TTE (ES = 0.78; ±0.37), enjoyment (ES = 0.85; ±0.49) and positive affect (ES = 0.78; ±0.65) were all greater in the VR condition compared to CON. Rating of perceived exertion (RPE) increased similarly over time in both conditions with the exception of minute 2, whereby RPE was lower in the VR condition (ES = 0.88; ±0.52). There were no changes in VO2 peak, b[La] and negative affect between conditions. These findings provide evidence to suggest that during the early stages of high intensity activity fully-immersive VR has the potential to reduce RPE. Further to this, VR also appears to increase the enjoyment of exercise at a high intensity and therefore increase the motivation to continue exercising. Future research should continue to explore this rapidly developing technology.
An innovative piece of digital technology which has recently come to the attention of sports scientists as a potential ergogenic aid is the use of immersive virtual reality (VR) technology. Whilst the effects of VR on performance have begun to be explored, the physiological and perceptual responses to exercise when combined with VR remain relatively unknown. Accordingly, this study investigated both the physiological and perceptual responses to exercise in a fully immersive virtual environment viewed through a stereoscopic head-mounted display. Thirteen recreationally active males (n=12) and females (n=1) (age = 24.9 ± 4.6 y; body mass = 78.7 ± 6.3 kg; stature = 178.6 ± 3.7 cm; VO2max = 55.1 ± 7.1 ml·kg-1·min-1) completed a time to exhaustion (TTE) test under control (CON) and virtual reality (VR) conditions in a repeated measures randomized crossover design. Effect sizes (ES) and magnitude-based inferences were calculated for all variables between conditions using a predesigned spreadsheet (Batterham & Cox, 2006). TTE (ES = 0.78; ±0.37), enjoyment (ES = 0.85; ±0.49) and positive affect (PA) (ES = 0.78; ±0.65) were all greater in the VR compared to CON condition. HR and RPE, analyzed over a 6 minute isotime, were lower at minute two only (ES = 0.33; ±0.38) and (ES = 0.88; ±0.52) respectively, in the VR compared to CON condition. There were no changes in VO2 peak, b[La] and negative affect (NA) between conditions. The use of a fully immersive VR headset in combination with a traditional cycling task was shown to elicit improvements in TTE performance and increase affective responses and enjoyment of the exercise, likely due to a dissociative effect. These findings support the use of fully immersive VR in the exercise domain as an ergogenic aid.
Sharland-Wong, Luke (University of Chester, 2015-09)
The purpose of this study was to investigate the performance enhancing capabilities of cycling specific orthotics during maximal cycling and how they relate to subject specific foot morphology and function. Twelve recreational cyclists took part in the study: eight male (age, 38 ± 8 yr; height, 180.41 ± 3.55 cm; body mass, 80.90 ± 6.50 kg) and four female (age, 35.92 ± 20.82 yr; height, 176.57 ± 1.94 cm; body mass, 77.20 ± 2.05 kg). Navicular height measurements were taken in weight bearing and non-weight bearing conditions to describe foot mobility. Subjects performed 2 maximal sprints (4s) on an isokinetic cycling ergometer at a cadence of 120rpm separated by 4mins of recovery in either conventional insoles or CSOs. Once completed the insole type was changed and the sprint protocol was repeated. Crank and joint-specific powers were obtained from instrumented force cranks and inverse dynamics methods respectively. Results from the paired samples t-test show no significant difference on a group level. Single subject analyses using magnitude based inferences show subjects could be grouped based on response (positive=2, non-responders=4, negative=6). Post-hoc analysis of joint-specific powers revealed negative responders tended to demonstrate reduced ankle reduced ankle power and range of motion (F= 4.97; d.f. 1, 9, p= 0.05), (F= 7.52; d.f. 1, 9, p= 0.02). The results highlight the need for caution when considering orthotic interventions and confirms the importance of the dual role of the ankle plantar flexors in cycling.
The aim of this study was to examine the effects of post-activation potentiation (PAP) on performance and physiological measures during endurance cycling. Eleven well trained male endurance cyclists (mean ± SD; 32.7 ± 10.3 yr; 70.7 ± 7.2 kg; VO2max 65.3 ± 5.3 ml·kg-1·min-1) performed two 4 km cycling time trials on separate days following 5 minutes recovery after a) a moderate intensity cycling warm-up at 60% of VO2peak for 6.5 minutes (CONTCOND), and b) a PAP-inducing cycling warm-up (PAPCOND) consisting of 5 minutes at 60% of VO2peak then 3 x 10 s at 70% of peak power interspersed with 30 s recovery, in a counterbalanced design. Before the start of the time trial blood lactate was significantly elevated following PAP-inducement compared to the moderate warm-up (4.88 ± 1.36 mM·L-1 vs 1.14m ± 0.26 mM·L-1). A non-significant possibly small improvement in completion time (1.7 ± 3.5 s, P = 0.17) and a non-significant increase in power (5.1 ± 10.5 W, P = 0.16) were attributed to PAPCOND. Following PAPCOND oxygen uptake (VO2) was elevated by 1.44 ± 1.65 ml·kg-1·min-1 (P = 0.02) and respiratory exchange ratio (RER) was decreased by 0.05 ± 0.02 (P < 0.01) compared to CONTCOND. All differences were greatest in the first 1500 m. A PAP-inducing warm-up leads to small performance improvements in endurance cycling that are associated with elevated blood lactate and increased VO2. These performance improvements are most evident in the early stages so would be of greatest benefit in short endurance cycle races.
Training at different cadences provides a different training stimulus (Brisswalter et al, 2000) which can be metabolic adaptations or skeletal muscle hypertrophy. Studies have considered the role of cadence in metabolic efficiency and/or participants perceptions of effort (Coyle et al, 1991. Cangley et al, 2009) however there is little literature measuring the efficiency of cadence in relation to muscle breakdown. This may be due to it being difficult to measure muscle breakdown in a noninvasive manner and without conducting a muscle biopsy. Creatine Kinase can be used as a marker of increased muscle breakdown and it is measured using a finger prick blood sample however this indirect method of measuring muscle breakdown is not as reliable and discrepancies in the results can occur as a result of differing response rates between participants or other health issues causing an increase in creatine kinase levels (Brancaccio et al, 2007). Coaches and athletes often use high intensity interval training as a method of improving metabolic efficiency (Laursen et al. 2005) however there is little research into the effects of high intensity interval training for skeletal muscle hypertrophy and strength training in cyclists. This literature review will form the basis for a research project that will consider the effects of differing cadences on muscle breakdown during a high intensity interval training protocol. This research hopes to provide recommendations for coaches and well trained cyclists to improve the training that they conduct to have the desired training stimulus they hope to achieve whether that be increasing muscle breakdown to cause hypertrophy and increase strength or increase adenosine triphosphate production by improving metabolic efficiency. By considering the existing literature surrounding cadence, this review hopes to provide potential reasoning for the results of the proceeding research project. The method’s for how best to conduct the research shall also be reviewed along with a discussion about the use of high intensity interval training protocol’s for well trained cyclists.
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