Sprint 45

Participants were instructed to perform a maximal straight line 15m sprint following a three second count down from the investigator. The starting point was determined as 1 m behind the first set of speed gates. The lights were activated when the subject broke the infrared beam at the start and again when passing through the timing gates situated at 15 m. Each subject performed three sprints with their best time being recorded.

3.4.2 Agility

Agility performance was determined using the 3-cone shuttle drill test (Figure 3.1), an agility test commonly used by the National Football League as a performance measure (McGee & Burket, 2003).

Figure 3.1: Schematic of agility test performed during baseline measures.

The athlete starts at cone 1. On his own volition, the athlete sprints as fast as possible and touches cone 2, which is 4.5m directly in front then immediately returns to cone 1. Without stopping, the athlete changes directions, corners cone 2, and sprints directly to cone 3, on the athlete’s right-hand side. The athlete circles cone 3 to his left, then returns to the first cone by cornering cone 2 and sprinting at full speed past cone 1, which marks the finish line. Infra-red timing gates were positioned at cone one and provided times to the nearest one-hundredth of a second. Participants completed the test 4 times, alternating between running to the left and to the right upon reaching the second cone, and interspersed with a 2 min rest period between each attempt to ensure adequate recovery (Spencer, Bishop, Dawson, & Goodman, 2005).

Each subject started 1 m behind the start line to ensure that the timing gates were not prematurely set off.

3.4.3 Vertical Jump

Participants were required to perform 3 countermovement VJs. The test began with the participant standing erect; thereafter the participant volitionally performed a countermovement jump in which they were required to squat down to their optimal depth (approximately 90o _{of hip & knee flexion)} and then immediately jump vertical in order to achieve maximal height (Williams, Oliver, & Faulkner, 2011).

3.5 Experimental trials

3.5.1 Pre-measures

Participant’s had a minimum one week recovery after their GXT to maximal functional capacity before commencing their first (of three) experimental trial. Participants’ body weight and resting BLa and heart rate were measured at the start of each experimental trial prior to undertaking the WU. Participants completed each experimental trial at a similar time of day to control the variation in circadian rhythm (Drust, Waterhouse, Atkinson, Edwards, &

Reilly, 2005) and the environmental conditions (15.9 ± 2.5 °C, humidity 62.8 ± 10.6 % and 998.9 ± 6.5 mmHg).

3.5.2 Warm up

A standard 20-min WU was performed during each experimental trial. The WU included football specific movements such as passing a football, general WU activities incorporating jogging and stride outs and dynamic stretching such as leg swings. The WU commenced with low intensity activities and following stretching activities culminated with higher intensity and football specific exercises. Physiological (BLa, HR) and perceptive measures (Feeling scale [FS; Appendix F] (Hardy & Rejeski, 1989), Felt arousal scale [FAS; Appendix G] (Svebak & Murgatroyd, 1985)) were taken immediately following the WU. For further information concerning these measures, please see section 3.7.1. At completion of the WU, subjects were then required to rest for either 5-, 10- or 20-min (5_Rec, 10_Rec and 20_Rec). During this time participants were restricted to passive recovery (i.e., by sitting down) or low intensity locomotion (i.e., walking) in an effort to replicate pre-match changing room conditions. Identical physiological and perceptive measures to those reported above were noted following the recovery duration. Thereafter, participants’ sprint, agility and vertical jump performance was re-assessed. The orders of these measures were kept consistent throughout testing, with vertical jump always being the final measure in an attempt to try and limit any influence of acute post activation potentiation (Gossen & Sale, 2000).

3.6 LIST

On completion of the performance measures, participants commenced the LIST (Nicholas, Nuttal, & Williams, 2000). The LIST test is a 90 minute intermittent sprinting protocol designed to replicate a football match (see section 2.11 for details regarding validity of match replication). The first 75 minutes of the LIST consists of 5 x 15 minutes blocks of exercise. Each 15-min block includes the following pattern of exercise:

· 3 x 20 m walk

· 1 x 20 m Sprint

· 4 s recovery

· 3 x 20 m jog at a running speed corresponding to 55 % of an individual’s V&O2 max

Figure 3.2: Schematic of running protocol during LIST. This cycle is repeated for the 15 minutes of each block in part 1 of LIST. Lengths were performed to a computerised beep programme with jog being 55% of V&O2 max while fast cruise corresponded to 95% of V&O2 max. The 4 second rest period following the maximal sprint is shown by *.

This pattern of exercise continues until 15-mins of exercise has been completed. The beep protocol for this test was made using specialized computer software. Dependent on each subject’s V&O2max, alterations were made to the amount of time subjects could take to complete each 20 m length. Participants had a 3-minute recovery period following completion of each 15-min block of exercise. During this interim period, participants reported their RPE, FS and FAS. On completion of the first, third and fifth block of exercise, BLa was also measured. Once the fifth block of exercise had been concluded, and following a further 3-min recovery, participants completed a time-to-exhaustion test. This test involved

participants running the 20 m distance at alternative speeds corresponding to 55% and 95% of

V&O2 max. This process continues until the subject reaches exhaustion and is unable to finish

the shuttle in the required time. Expected time for exhaustion testing is 10-15 minutes, taking the total exercise time of the LIST test to approximately 90 minutes (Nicholas, Nuttal, & Williams, 2000). Physiological and perceptive measures were collected on completion of the time-to-exhaustion test. Participants completed an identical test protocol during the remaining experimental trials, although an alternative recovery was implemented following the WU.