Changes in skeletal muscle architecture following a cycloergometer test to exhaustion in athletes

We determined whether a short-term exhaustive dynamic exercise (cycling) for about 18 min induces changes in the intramuscular architecture of the quadriceps in trained athletes. Thirty-five mate athletes (age 28.8 +/- 19.8 years; height: 175.4. +/- 5.5 cm; weight: 74 +/- 11.5 kg; average years spent training: 11.1 +/- 8.4 years; mean weekly duration of training: 10.4 +/- 3.20 h) underwent an incremental cycloergometer test to exhaustion. Muscle thickness of the right quadriceps femoris (rectus femoris + vastus intermedius), and the angle of pennation of the right vastus lateralis on the quadriceps tendon were determined by high-resolution real time ultrasonography. Quadriceps thickness increased from 32.1 +/- 3.3 mm at rest to 34.9 +/- 3.0 mm after the test (p = 0.001). The pennation angles were significantly greater after exercise (12.8 +/- 2.1 degrees at rest; 14.4 +/- 2.5 degrees after the test (p = 0.001)). There are marked changes in intramuscular architecture of the quadriceps following a bout of cycloergometer exercise to exhaustion, with significant increase of quadriceps thickness and pennation angle. Ultrasonography allows to evaluate the changes of muscle architecture following exercise. (c) 2007 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.