Consequences of Combining Strength and Endurance Training Regimens

Abstract

A common belief among many clinicians and trainers is that intensive simultaneous training for muscle strength and cardiovascular endurance is counterproductive. To test this premise, 14 healthy, untrained men trained four days per week for 20 weeks on a bicycle ergometer for endurance (END Group, n = 4), on an isokinetic device for increased torque production (ITP Group, n = 5), or on both devices (COMBO Group, n = 5) The ITP and COMBO groups had equal torque gains throughout the study (234 ± 45 and 232 ± 23 N·m, respectively). After 11 weeks, both END and COMBO groups had similar gains in maximal oxygen consumption (V̇o_{2 max}) (in milliliters per kilogram of body weight per minute). During the last half of the study, however, the END Group had a significant gain in V̇o_{2 max} (p < .05) of 4.7 ± 1.2 mL·kg⁻¹·min⁻¹, whereas the COMBO Group had a nonsignificant gain (p > .05) of 1.8 ± 0.6 mL·kg⁻¹·min⁻¹. In harmony with this finding, the END Group showed a significant increase (p < .05) in citrate synthase activity (15.5 ± 7.9 μmol·g⁻¹·min⁻¹), whereas the COMBO Group had no significant increase. The authors concluded that simultaneous training may inhibit the normal adaptation to either training program when performed alone. The extent of the interference probably depends on the nature and intensity of the individual training program.