Do Muscle Recruitment Patterns Differ Between Trained and Novice Cyclists?

Abstract

1152 Measures of performance, cycling effciency and preferred cadence differ between trained and novice cyclists. On this basis, it has long been assumed that trained cyclists utilize more refined patterns of muscle recruitment than novice cyclists. However, there is little evidence to support this assumption. Measures of performance, effciency and cadence are not specific to the neuromuscular system, and previous electromyographic (EMG) studies have been limited by insensitive methodology and have only reported comparisons of individual cyclists. PURPOSE: To determine if patterns of distal lower limb muscle recruitment differ between trained and novice cyclists. METHODS: Participants were seven trained and eight novice cyclists who had cycled 295.9 ± 33.6 and 43.6 ± 11.6 km per week in the preceding three months, and had been cycling for 9.4 ± 1.7 and 1.3 ± 1.3 years, respectively. Electromyographic (EMG) activity in tibialis anterior (TA), tibialis posterior (TP), peroneus longus (PL), gastrocnemius lateralis (GL) and soleus (SOL) was recorded using selective intramuscular electrodes. Cycling trials were conducted on each participant's bike secured on a magnetic trainer, using the participant's shoes and clipless pedal system. Recordings were made at cadences of 77.5 ± 0.04 (trained) and 77.5 ± 0.15 (novice) rpm. Cycling intensity was standardized using perceived exertion. RESULTS: Differences were evident between trained and novice cyclists in recruitment patterns for all muscles. More specifically, novice cyclists were characterized by greater variation in patterns of muscle recruitment between cyclists (p < 0.01 for TA, TP, PL and SOL) and between pedal strokes for individual cyclists (p < 0.05 for TP, PL, GL and SOL), greater and more variable muscle coactivation, and less modulation of muscle activity, i.e. in novice cyclists, the relative amplitude of EMG was higher in periods between primary EMG bursts. CONCLUSIONS: These data support the argument that trained cyclists utilize more refined patterns of muscle recruitment than novice cyclists. These differences are most likely the result of repeated performance of the motor task in training and competition, and subsequent adaptation of the neuromuscular system.