Nelson, AG, Kokkonen, J, Winchester, JB, Kalani, W, Peterson, K, Kenly, MS, and Arnall, DA. A 10-week stretching program increases strength in the contralateral muscle. J Strength Cond Res 26(3): 832–836, 2012—It was questioned whether a unilateral stretching program would induce a crosstraining effect in the contralateral muscle. To test this, 13 untrained individuals participated in a 10-week stretching program while 12 other untrained individuals served as a control group. For the experimental group, the right calf muscle was stretched 4 times for 30 seconds, with a 30-second rest between stretches, 3 d·wk−1 for 10 weeks. Strength, determined via 1 repetition maximum (1RM) unilateral standing toe raise, and range of motion (ROM) were measured pre-post. In the treatment group, the stretched calf muscle had a significant (p < 0.05) 8% increase in ROM, whereas the nonstretched calf muscle had a significant 1% decrease in ROM. The 1 RM of the stretched calf muscle significantly increased 29%, whereas the 1RM of the nonstretched calf muscle significantly increased 11%. In the control group, neither 1RM nor ROM changed for either leg. The results indicate that 10 weeks of stretching only the right calf will significantly increase the strength of both calves. Hence, chronic stretching can also induce a crosstraining effect for strength but not for the ROM. This study also validates earlier findings suggesting that stretching can elicit strength gains in untrained individuals.
1Department of Kinesiology, Louisiana State University, Baton Rouge, Louisiana; 2Exercise and Sport Science Department, Brigham Young University—Hawaii, Laie, Hawaii; 3Department of Kinesiology, Leisure and Sports Science, East Tennessee State University, Johnson City, Tennessee; and 4Physical Therapy Department, East Tennessee State University, Johnson City, Tennessee
Address correspondence to Dr. Arnold G. Nelson, anelso@.lsu.edu.