Affiliations: [a] Exercise Research Laboratory, School of Physical
Education, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
Note: [] Corresponding author: Fábio Juner Lanferdini,
Laboratório de Pesquisa do Exercício, Escola de
Educação Física, Universidade Federal do Rio Grande do
Sul, Rua Felizardo, 750, ZIP 90690-200, Porto Alegre, RS, Brazil. Tel.: +55 51
33085859; Fax: +55 51 33085858; E-mail: fabiolanferdini@gmail.com
Abstract: BACKGROUND: Non-specific adaptation from training can elicit similar
muscle volume and muscle activation between cyclists and triathletes which
differ in comparison to non-athletes. OBJECTIVE: To compare muscle volume, muscle activation and pedal
forces of cyclists, triathletes and non-athletes. METHODS: Twelve cyclists, ten triathletes and twelve non-athletes
performed an incremental test to determine their maximal power output
(PO_{MAX}). Quadriceps and triceps surae volume were
estimated from ultrasound images taken at rest, while pedal forces and muscle
activation were recorded at PO_{MAX} at 90 rpm. RESULTS: Quadriceps volume was larger in cyclists (∼22%, p<
0.04) and triathletes (∼40%, p< 0.01) compared to non-athletes. Higher
activation of rectus femoris (∼55%, p=0.01) and tibialis anterior
(∼88%, p=0.01) were observed for triathletes compared to non-athletes at
the first quarter of the pedaling cycle. Triathletes also showed higher
activation for tibialis anterior than cyclists (∼68%, p=0.03) at the first
quarter. Non-athletes applied greater force on the pedal compared to
triathletes at the first quarter (∼42%, p< 0.01). Pedal force
effectiveness was higher for athletes (37–44%, p< 0.02) compared to
non-athletes at the fourth quarter. CONCLUSIONS: Similar muscle volume and muscle activation between
cyclists and triathletes may be related to a similar training volume supporting
differences relative to non-athletes.
