Secondary Logo

Journal Logo

Abernethy Peter J.; Howard, Alf; Quigley, Brian M.
Journal of Strength and Conditioning Research: November 1996
Article: PDF Only
Free

ABSTRACTMany raders of isokinetic research assume that torque and instantaneous power data parallel one another. The present study tested this assumption. Isokinetic torque (T30) and instantaneous power (P30) were analyzed 30° from full extension during maximal isokinetic leg extensions for 15 subjects before and after 7 weeks of endurance (E: n = 5), power (P: n = 5), and concurrent endurance and power training (C: n = 5). In all 3 conditions, increments in P30 were limited to the higher contractile speeds (>3.12 rad · sec−1) (i.e., there was a significant interaction). In contrast, torque (T30) was increased at all contractile speeds (0.52–5.20 rad · sec−1) (i.e., the interaction was not significant). The different torque and power findings occurred despite training producing identical changes (i.e., effect sizes) in T30 and P30 in all training conditions. The significant interaction for power data was attributed to the multiplication of contractile speed, a nonconstant multiplier, with T30 values to obtain P30 scores. Isokinetic T30 and P30 data do not necessarily mirror one another for contractile speeds between 0.52 and 5.20 rad · sec−1.

Many raders of isokinetic research assume that torque and instantaneous power data parallel one another. The present study tested this assumption. Isokinetic torque (T30) and instantaneous power (P30) were analyzed 30° from full extension during maximal isokinetic leg extensions for 15 subjects before and after 7 weeks of endurance (E: n = 5), power (P: n = 5), and concurrent endurance and power training (C: n = 5). In all 3 conditions, increments in P30 were limited to the higher contractile speeds (>3.12 rad · sec−1) (i.e., there was a significant interaction). In contrast, torque (T30) was increased at all contractile speeds (0.52–5.20 rad · sec−1) (i.e., the interaction was not significant). The different torque and power findings occurred despite training producing identical changes (i.e., effect sizes) in T30 and P30 in all training conditions. The significant interaction for power data was attributed to the multiplication of contractile speed, a nonconstant multiplier, with T30 values to obtain P30 scores. Isokinetic T30 and P30 data do not necessarily mirror one another for contractile speeds between 0.52 and 5.20 rad · sec−1.

© 1996 National Strength and Conditioning Association