Reliability of a Protocol to Elicit Peak Measures Generated by the Lower Limb for Semi-recumbent Eccentric Cycling

Abstract

Semi-recumbent eccentric (ECC) cycling is increasingly used in studies of exercise with healthy and clinical populations. However, workloads are generally prescribed using measures obtained during regular concentric cycling. Therefore, the purpose of the study was to quantify the reliability of measures derived from a protocol that elicited peak ECC torque produced by the lower limb in a semi-recumbent position. Experiments were carried out on a dynamometer in a seated, semi-recumbent position identical to that of a custom-built ECC cycle, a modified Monark recumbent cycle. Thirty healthy participants completed two testing sessions. Each session comprised three series of six repetitions of a peak ECC torque protocol (PETP) on an isokinetic dynamometer. Absolute and relative reliability of peak torque, power, angle of peak torque, and work (recorded for each repetition) was determined using coefficient of variation (CV) and intraclass correlation coefficient (ICC), respectively. Ratings of perceived exertion (RPE), muscle soreness, and perceived effort (PE) were recorded pre-PETP, immediately post-PETP, and 1-min post each PETP. The protocol showed absolute reliability values <15% for mean peak (CV = 10.6–12.1) torque, power (CV = 10.4–12.3), angle of peak torque (CV = 1.2–1.4), and work (CV = 9.7–12.1). Moderate to high between-test relative reliability is reported for mean and highest torque (ICC = 0.84–0.95; ICC = 0.88–0.98), power (ICC = 0.84–0.94; ICC = 0.89–0.98), and work (ICC = 0.84–0.93; ICC = 0.88–0.98), respectively. Within-session peak torque, peak power, and peak work showed high relative reliability for mean (ICC = 0.92–0.95) and highest (ICC = 0.92–0.97) values. Overall, the PETP test provides a reliable way of determining peak ECC torque specific to semi-recumbent ECC cycling that may be used to prescribe workloads for this form of exercise.

A Semi-recumbent Eccentric Cycle Ergometer Instrumented to Isolate Lower Limb Muscle Contractions to the Appropriate Phase of the Pedal Cycle

“…The participant performed 15min of isokinetic semi-recumbent ECC cycling at an individually prescribed power output (328 Watts, fixed cadence of 60rpm). The prescribed power output was a summation of 10% of the participant’s peak power output value (3,013 Watts), recorded during a peak test (PETP) specific to the semi-recumbent position ( Walsh et al, 2021 ), and the zero-offset value (27 Watts). In line with industry procedure, zero offsetting defines a zero “0” baseline value for recording torque and power output values.…”

Reliability and Variability of Lower Limb Muscle Activation as Indicators of Familiarity to Submaximal Eccentric Cycling

“…Participants completed a single experimental visit designed to determine within-session familiarization, based on variability and reliability of muscle EMG patterns, to ECC cycling. Participants performed three peak eccentric torque protocol (PETP) tests (Walsh et al, 2021b), nine countermovement jumps (CMJ) and 15 min of ECC cycling (Figure 1A). Prior to ECC cycling, each participant performed 1 minute of non-resisted ECC pedaling (i.e., freewheeling) to become aware of the motion induced by the cycle ergometer.…”

“…Cadence was fixed at 60 rpm. Eccentric cycling intensity was prescribed at 10% of peak power output obtained during the PETP tests (Walsh et al, 2021b). The prescribed ECC cycling intensity was calculated from peak power output values recorded during the PETP test.…”

“…The prescribed ECC cycling intensity was calculated from peak power output values recorded during the PETP test. The PETP test is a recently developed test where participants apply a maximal ECC resistive force to a backwards moving pedal arm, fixed to an isokinetic dynamometer (Walsh et al, 2021b). The PETP test replicates the position (i.e., semi-recumbent), speed (60 rpm) and phase of an ECC pedal cycle (Walsh et al, 2021b).…”

“…Developing a single session familiarization protocol of adequate duration (>10 min) (Zych et al, 2018) and intensity (Walsh et al, 2021b) could be better used to familiarize participants with ECC cycling. Furthermore, single session protocols, as opposed to multiple visit protocols, reduce time constraints that could affect participation (Martin et al, 2007;Thompson et al, 2016).…”