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Purpose: To examine acute responses of force production and oxygen uptake to combined strength (S) and endurance-running (E) loading sessions in which the order of exercises is reversed (ES vs SE). Methods: This crossover study design included recreationally endurance-trained men and women (age 21-45 y; n = 12 men, 10 women) who performed ES and SE loadings. Force production of the lower extremities including countermovement-jump height (CMJ) and maximal isometric strength (MVC) was measured pre-, mid-, and post-ES and -SE, and ground-reaction forces, ground-reaction times, and running economy were measured during E. Results: A significant decrease in CMJ was observed after combined ES and SE in men (4.5% ± 7.0% and 6.6% ± 7.7%, respectively) but not in women (0.2% ± 8.5% and 1.4% ± 7.3% in ES and SE). MVC decreased significantly in both men (20.7% ± 6.1% ES and 19.3% ± 9.4% SE) and women (12.4% ± 9.3% ES and 11.6% ± 12.0% SE). Stride length decreased significantly in ES and SE men, but not in women. No changes were observed in ground-reaction times during running in men or women. Performing S before E caused greater (P < .01) oxygen uptake during running in both men and women than if E was performed before S, although heart rate and blood lactate were similar between ES and SE. Conclusions: Performing S before E increased oxygen uptake during E, which is explained, in part, by a decrease in MVC in both men and women, decreased CMJ and stride length in men, and/or an increase in postexercise oxygen consumption. [ABSTRACT FROM AUTHOR]

The study examined the acute neuromuscular and metabolic responses and recovery (24 and 48 h) to combined strength and endurance sessions (SEs). Recreationally endurance trained men (n= 12) and women (n= 10) performed: endurance running followed immediately by a strength loading (combined endurance and strength session (ES)) and the reverse order (SE). Maximal strength (MVC), countermovement jump height (CMJ), and creatine kinase activity were measured pre-, mid-, post-loading and at 24 and 48 h of recovery. MVC and CMJ were decreased (P< 0.05) at post-ES and SE sessions in men. Only MVC decreased in ES and SE women (P< 0.05). During recovery, no order differences in MVC were observed between sessions in men, but MVC and CMJ remained decreased. During recovery in women, a delayed decrease in CMJ was observed in ES but not in SE (P< 0.01), while MVC returned to baseline at 24 h. Creatine kinase increased (P< 0.05) during both ES and SE and peaked in all groups at 24 h. The present combined ES and SE sessions induced greater neuromuscular fatigue at post in men than in women. The delayed fatigue response in ES women may be an order effect related to muscle damage. [ABSTRACT FROM AUTHOR]

The article reports on research conducted to investigate acute neuromuscular and endocrine responses and recovery to a single session of combined endurance and strength loading using two loading orders. Researchers evaluated 42 male subjects. They found that both loading conditions led to significant acute reductions in maximal force production, rapid force produced in 500 milliseconds and countermovement jump height whereas no significant differences between the 2 loadings were observed.

The article presents a study which aims to investigate the acute effects to neuromuscular and endocrine responses of variable and constant resistance exercises during hypertrophic loadings and maximal strength. The study involved thirteen young men who took part in four loadings in a counterbalanced order. The result shows that force and quadriceps electromyogram (EMG) is greater than 120 to 180 degrees knee angle during variable resistance hypertrophic loadings. The conclusion is that a bigger level of neuromuscular fatigue and larger responses occur in serum hormone concentrations after hypertrophic loading.