PARTICIPANTS

Six highly-trained sprint cyclists (4 male, 2 female, Table 3.1) were recruited for the trials. The athletes were either national development squad riders or riders who had trained and competed at national and international level alongside the current national high performance squad. Trials were conducted towards the end of the competitive season a few weeks after the national track cycling championships. The athletes were in near peak performance condition, with no musculoskeletal injuries. In addition to their performance status, participants were selected for the study based on having a minimum of two years strength training background and training exclusively for sprint events.

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All participants had the risks and benefits of the investigation explained to them (Appendix 1), completed a pre-exercise health questionnaire (Appendix 2) and provided written informed consent (Appendix 3) prior to commencing the trials. Ethical approval was provided by the Massey University Ethical Committee (Appendix 4).

Table 3.1 Summary of Participant Characteristics.

Variables Mean rSD

Age (years) 19.2 r 3.2

Height (cm) 175.2 r 7.0

Body mass (Kg) 75.5 r 9.8

Sprint cycling (years) 4.0 r 1.5

Strength training (years) 3.5 r 1.2

Peak Isometric Pedal Torque (Nm)* 255.85r37.75

* average of peak left and right leg torque produced in isometric potentiation protocol

3.3 PROTOCOL

Trials were conducted in the Sport Science Laboratory of Massey University’s Albany Campus over a 4-week period, with test days separated by at least one full week (Figure 3.1). Environmental conditions in the laboratory for all trials represented current daily room temperature, humidity and air pressure on each occasion and was recorded as 21.87 r 0.40qC, 45 r 5%, and 1008 r 10 mmHg respectively (DSE deluxe weather station, DSE Ltd, New Zealand).A tendency has been reported for improved power performance in tests conducted later in a day and so testing on each day was conducted in a single afternoon session with athletes timetabled for arrival in sequential order (Chtourou & Souissi, 2012). Scheduling of arrival times maintained testing for each athlete within an hour of the same start time each day in order to control for circadian rhythm. A single familiarisation session, following the same protocol, was conducted 4-weeks prior to testing. While it would have been preferable for this session to have been closer to the test days, the athletes’ competitive schedule meant this was not possible.

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Figure 3.1 Summary of the Experimental Method.

Participants were instructed to arrive at the laboratory having refrained from eating within the 2- hour period prior to testing and having maintained a normal diet without supplementation or caffeine intake for the previous 24 hours. Participants further recorded all fluid in-take during this period to ensure euhydration status before starting the trial. Fluid in-take during the trial was restricted to water. This was permitted ad libitum.

On each test day the athletes arrived at the laboratory at their designated time and remained seated for at least 20 minutes to ensure they were in a rested state prior to recording baseline measures of heart rate (Short-range telemetry: Polar S610i, Polar Electro, Finland) and blood lactate (BD- microtainer contact-activated lancet, Lactate Pro LT-1710 hand-held analyser, Arkray, Kyoto, Japan). Athletes provided bike set-up information determined by their own track bike and both the test (inertial-load) and potentiation (high-inertia) ergometers were adjusted to match the required seat height and handlebar height. The test ergometer was, additionally, adjusted to optimise seat and handlebar fore-aft position for each athlete. Each athlete provided their own clipless racing pedals which were transferred to the relevant ergometer prior to each component of the trial.

Standardised Warm-Up (17 min) Baseline Performance Test Performance Retesting @ 4, 8, 16 min CON: 10 min active rest DYN: High-Inertia Erg 4 x 4 crank cycles 2 min rest ISO: High-Inertia Erg 4 x 5s isometric 2 min rest

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Having recorded baseline measures and adjusted the bike set-up, participants completed a 17- minute standardised warm-up on the test ergometer. The content of the warm-up was based on the experimental protocol of Tomaras and MacIntosh (2011) which reportedly produced higher peak power output and greater work done in subsequent sprint performance, when compared to a traditional sprint cycling warm-up. Where the original protocol had utilised a fixed gearing of 46:16, the current warm-up was conducted on the test ergometer which restricted gearing to 62:13. As observed in Table 3.2 the two key components of the protocol are a progressive build up in intensity as determined by relative heart rate and an acceleration of speed before completing a 6-second maximal sprint. Despite the difference in gearing, the current trial followed the exact execution of the protocol with step-wise incremental heart rate achieved by combination of increasing speed and application of the ergometer’s friction-brake.

Table 3.2 Standardised Warm-Up Protocol.

Time (min:s) Classification Instruction

0:00– 5:00 General warm-up 60% HRmax

5:00–10:00 65% HRmax

10:00–15:00 70% HRmax

15:00–15:30 Acceleration Progressive to 35 km/h

15:30–15:36 Sprint 6-s maximal

15:36–17:00 Recovery Cycle lightly, as if preparing

to stop on track

On completion of the warm-up, athletes remained seated and stationary whilst the ergometer was prepared for the first test effort. The test ergometer was custom-built to modified design specifications based on the inertial-load ergometer used by Martin et al. (1997); where Martin and co’s ergometer utilised an intermediate drive system, the current design utilised a single-geared system with increased gear ratio (62:13) and flywheel weight (32kg) to create the required inertia. The inertial-load ergometer allows determination of a complete power profile in a single effort with

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resistance provided solely by the moment of inertia of the flywheel. Test conditions for the current study involved the athlete conducting a seated acceleration with maximal effort from a standing start, aiming to achieve highest velocity in as short a time as possible. Lasting ~6 seconds, the effort, therefore, provided performance data across the functional range of the force-velocity curve, from which the power-velocity relationship, temporal profiles and total work done, could be derived. During the test efforts pedal torque was obtained using SRM cranks (Schoberer Rad Messtechnik, Jülich, Germany) with strain-gauges at the hub, calibrated at the beginning of each test day as per manufacturer’s instructions. Sensors on the crank and flywheel provided information on the pedal and flywheel angular velocities. SRM data was captured at 256 Hz and downloaded to personal computer for analysis.

Pre-intervention sprint tests were conducted within 2 minutes of finishing the warm-up. In preparation for the test, athletes were asked to position their pedals with the right foot leading and pedal at 60° past top dead centre (TDC). Measures of heart rate and blood lactate were then taken and when the athlete was ready, the data-logger was started and they were given a count-down “3- 2-1-GO!”. The athlete then accelerated all-out for ~6 seconds, remaining seated in the saddle throughout the effort. When acceleration had deemed to plateau, they received the command “done”, the data-logger was stopped and the athlete decelerated back to standstill. Strong verbal encouragement was given throughout the test.

Following 4-minutes active rest, participants executed one of three interventions: a dynamic (DYN) potentiation protocol, an isometric (ISO) potentiation protocol or a control trial (CON) consisting of active recovery for the total equivalent time. The potentiation protocols were conducted on a custom-built high-inertia ergometer designed to provide maximal loading over the first 4-5 cranks of acceleration (Section 3.4). On completion of the appropriate intervention, participants rested

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actively for a further 4 minutes before repeating the test effort on the inertial-load ergometer. Repeat testing was additionally conducted at 8 and 16 minutes post-potentiation with participants instructed to maintain active rest conditions between tests. Each repeat effort was conducted under the same conditions as the baseline test and to maintain accuracy in the timing of repeat trials, athletes were asked to be ready to go on the test ergometer 2 minutes ahead of each test point. Active rest was specifically monitored during the recovery periods in order to maintain core temperature of the athletes: activities consisted of walking around the laboratory and intermittent unloaded cycling on a stationary ergometer (Monarch Ergomedic 874E, Netherlands). At the conclusion of the trial, the athlete completed a 15-minute cool down of their own choice on the same ergometer.