Date of Award

2017

Document Type

Thesis

Publisher

Edith Cowan University

Degree Name

Doctor of Philosophy

School

School of Medical and Health Sciences

First Supervisor

Associate Professor Chris Abbiss

Second Supervisor

Dr Dale Chapman

Third Supervisor

Kevin Thompson

Abstract

Augmented feedback has been shown to improve performance and influence pacing in various physical activities. However, few studies have investigated its effects on performance and pacing in striking combat sports. Additionally, despite the plethora of studies examining the influence of feedback in untrained individuals, there is a lack of research examining the effects of such feedback in trained participants. Considering the important role of feedback in training and competition, the purpose of this thesis is to examine the effects of three different but inter-dependent methods of augmented feedback on performance of combat, and resistance trained athletes.

Study 1 examined the type and frequency of verbal feedback provided by national level coaches to their athletes during important competitions. A microphone was secured on the shirts of 12 coaches and the feedback they provided was recorded, transcribed and categorised into three common feedback themes: attentional focus (internal, external, neutral), autonomy support (controlling, supportive, neutral) and feedback valence (positive, negative, neutral). Collectively, 445 feedback statements from 12 coaches during 26 bouts, of which 14 were won and 11 were lost, were analysed. Coaches provided on average 8 feedback statements per round. Excluding neutral statements, coaches delivered more internal (15%) compared with external focus feedback (6%), more controlling (53%) compared with autonomy-supportive feedback (4%), and more feedback that would affect athletes’ expectancies in a positive (29%) rather than negative direction (12%). Furthermore, during winning bouts coaches delivered more positive (36% vs. 18%), less internal (12% vs. 19%) and less controlling (50% vs. 58%) feedback, when compared with losing bouts. Hence, for the most part, coaches used feedback that is sub-optimal accordingly to the existing body of literature. Additionally, winning and losing bouts were associated with different types of feedback which suggests a possible training strategy

Study 2 examined if internal or external focus of attention effect maximal force production during an isometric mid-thigh pull (IMTP) among 18 trained athletes (8 females & 10 males). Athletes performed three IMTP trials a day for three consecutive days. The first day consisted of a familiarization session in which athlete’s received control instructions. In the following two days athletes received either control, internal or external focus of attention instructions in a randomized, within-subject design. Compared to an internal focus of attention, athletes applied 9% greater force using an external focus of attention (P< 0.001; effect size [ES]= 0.33) and 5% greater in the control condition (P= 0.001; ES= 0.28). A small positive 3% advantage was observed with an external focus of attention compared with control conditions (P= 0.03; ES= 0.13). This study demonstrates that even in relatively simple exercises that require maximal force production, external focus leads to superior performance compared to internal focus as well as control conditions, among resistance trained participants.

Study 3 investigated a similar question as study 2, but the outcome measures were combat sports related. Specifically, the effects of external, internal and neutral feedback were examined in relation to punching velocity (m·s-¹) and normalized impact forces (N·kg-¹) among intermediate (n= 8) and expert (n= 7) competitive boxers and kickboxers. Athletes completed three rounds of 12 maximal effort punches delivered to a punching integrator on three separate days. Day one was a familiarization session with only control instructions provided. In the following two days athletes randomly received internal, external or neutral instructions prior to each of the three rounds. Athletes punching with external focus were 4% faster and 5% more forceful than internal focus (P< 0.05), and 2% faster and 3% more forceful than control (P< 0.05). Furthermore, experts punched 11% faster and with 13% greater force compared with intermediate athletes (P< 0.05). Punching forces were enhanced with external compared to both internal and control condition, among well-trained combat striking athletes, and should implemented by combat sports coaches.

Study 4 investigated how performing in-front of a mirror influences performance in single and multi-joint tasks, and compared the mirror condition to the established performance effects of internal and external focus instructions in a two part experiment. In the single-joint experiment 28 resistance-trained participants (14 males and 14 females) completed two elbow flexion maximal voluntary isometric contractions under four conditions: mirror, internal, external and neutral instructions. During these trials, surface electromyography (EMG) activity of the biceps and triceps were recorded. In the multi-joint experiment the same participants performed counter-movement jumps on a force plate under the same four conditions. Single-joint experiment: External instructions led to greater normalized force production compared to all conditions (P≤ 0.02, ES= 0.46-1.31, 8-30 N). No differences were observed between neutral and mirror conditions (P= 0.15, ES=0.15, 5 N), but both were greater than internal focus (P< 0.01, ES= 0.79-1.84, 15N). Surface EMG activity was comparable across conditions (P≥ 0.1, ES= 0.10-0.21. ~2%). Multi-joint experiment: Despite no statistical difference (P= 0.10), a moderate effect size was observed for jump height whereby external focus was greater than internal focus (ES= 0.51, 1 cm). No differences were observed between neutral and mirror conditions (ES= 0.01, 0.1 cm), but both were greater than internal focus (ES= 0.20-22, 0.6 cm). The mirror condition led to superior performance compared to internal focus, inferior performance compared to external focus, and was equal to a neutral condition in both tasks. These results provide novel and practical evidence concerning mirror training during resistance type training.

Study 5 was a two part study set to examine how self-controlled practice effects performance of competitive athletes. Part 1 was a single case-study design with a world-champion kickboxer. We investigated whether giving the athlete a choice over the order of punches would affect punching velocity and impact force. The athlete completed 2 rounds of 12 single, maximal effort punches (lead straight, rear straight, lead hook & rear hook) delivered to a punching integrator in a counterbalanced order over 6 testing days. In one round the punches were delivered in a predetermined order while in the second round the order was self-selected by the athlete. When allowed to choose the punching order, the world-champion punched with greater velocities (6-11%) and impact forces (5-10%). In Part 2, the same testing procedures were repeated with 13 amateur male kickboxers over 2 testing days. Similar to Part 1, the athletes punched with significantly greater velocities (6%, P< 0.05) and normalized impact forces (2%, P< 0.05) when allowed to choose the punching order. Hence, small choices concerning practice conditions enhance punching performance of competitive striking athletes.

Study 6 investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results, which differ from previous literature, could stem from the elite status of the athletes involved; indicating that task proficiency might mitigate against changes in performance and pacing variability when false performance feedback is manipulated.

Collectively, this thesis enhances our understanding of: i) the common feedback statements provided by coaches, ii) how such feedback influence performance and pacing of combat athletes, and iii) how this feedback also influence performance during common resistance type exercises.

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