We evaluated the effects of concurrent strength and aerobic endurance training on muscle strength and endurance, body composition, and flexibility in female college athletes and compared two concurrent exercise (CE) protocols. Twenty-eight women (mean age, 19.6 years) were divided into two matched groups and evaluated before and after a vigorous, 11-week, 3-days per week CE training program. One group did serial CE consisting of a warm-up, resistance exercises at low heart rate (HR), aerobics, and a range of motion cool down. The other group did integrated CE consisting of aerobics, the same resistance exercises at high HR achieved by cardioacceleration before each set, and the same range of motion cool down. The two protocols were balanced, differing only in the timing and sequence of exercises. Serial CE produced discernible (p < 0.05) increases in lower- (17.2%) and upper- (19.0%) body muscle strength and fat-free mass (FFM) (1.8%) and trends toward greater lower-body muscle endurance (18.2%) and reduced upper-body flexibility (-160.4%). Integrated CE produced discernible increases in lower- (23.3%) and upper- (17.8%) body muscle strength, lower-body muscle endurance (27.8%), FFM (3.3%), and lower-body flexibility (8.4%) and a decline in fat mass (-4.5%) and percent body fat (-5.7%). Integrated CE produced discernibly larger gains than serial CE for six of nine training adaptations. Effect sizes were generally moderate (44.4% of discernible differences) to large (33.3%). We conclude that serial CE produces adaptations greater than those reported in the literature for single-mode (strength) training in athletes, whereas integrated CE produces discernibly greater gains than serial CE. The results suggest synergy rather than interference between concurrent strength and aerobic endurance training, support prescription of CE under defined conditions, establish the importance of exercise timing and sequence for CE program outcomes, and document a highly effective athletic training protocol.

We evaluated the effects of concurrent strength and aerobic endurance training on cardiovascular and cardiorespiratory adaptations in college athletes and compared two concurrent exercise (CE) protocols. Separate experiments were performed on 30 women (mean age 19.6 years) and 20 men (20.4 years). In both experiments, subjects were divided into two groups (serial CE and integrated CE) matched for initial physical condition and trained in a vigorous 3-day per week CE program of 9 (men) to 11 (women) weeks. The two CE training protocols were equilibrated for exercise mode, intensity, and volume, differing only in the timing and sequence of exercises. During training, serial CE discernibly (p < 0.05) increased cardiovascular adaptation in women, indicated by reduction (-5.7%) in active heart rate (HR) (HR/aerobic exercise intensity), whereas integrated CE discernibly reduced active HR in women (-10.7%) and men (-9.1%). Before and after comparisons in the larger sample of women showed that serial CE discernibly reduced systolic and diastolic blood pressure (BP) (-8.7% and -14.0%, respectively), increased estimated [latin capital V with dot above]o2max (18.9%), and produced a trend (0.10 > p > 0.05) toward reduced resting HR (-4.9%). Integrated CE in women discernibly reduced systolic and diastolic BP (-13.2% and -12.6%, respectively), increased estimated [latin capital V with dot above]o2max (22.9%), and produced a trend toward reduced resting HR (-2.4%). Integrated CE produced discernibly larger gains than serial CE or a trend for four of six training adaptations. Effect sizes were generally large (60.0% of discernible differences). We conclude that, for cardiovascular and cardiorespiratory adaptations in athletes, strength and endurance training are compatible and that exercise timing and sequence significantly influence training adaptations, complimenting our previous similar conclusions for strength, muscle endurance, body composition, and flexibility.

A nonstandard finite difference method for solving autonomous dynamical systems is constructed. The proposed numerical method is computationally efficient and easy to implement. It is designed so that it preserves positivity of solutions and the local behavior of the dynamical system near equilibria.

Based on previous research by Dimitrov and Kojouharov, a class of dynamically consistent numerical methods are analysed for general n-dimensional productivedestructive systems (PDS). Using this analysis, a methodology for constructing positive and elementary stable non-standard numerical methods is established. The nonstandard approach, pioneered by Mickens, results in qualitatively superior numerical methods when compared to the standard approach. PDS model a wide range of dynamical systems, including systems with biological, chemical and physical interactions. An application to a four-dimensional biological system is presented.

We compared delayed-onset muscle soreness (DOMS) induced by anaerobic resistance exercises with and without aerobic cardioacceleration before each set, under the rationale that elevated heart rate (HR) may increase blood perfusion in muscles to limit eccentric contraction damage and/or speed muscle recovery. In two identical experiments (20 men, 28 women), well-conditioned athletes paired by similar physical condition were assigned randomly to experimental or control groups. HR (independent variable) was recorded with HR monitors. DOMS (dependent variable) was self-reported using Borg's Rating of Perceived Pain scale. After identical pre-training strength testing, mean DOMS in the experimental and control groups was indistinguishable (P > or = 0.19) for musculature employed in eight resistance exercises in both genders, validating the dependent variable. Subjects then trained three times per week for 9 (men) to 11 (women) weeks in a progressive, whole-body, concurrent training protocol. Before each set of resistance exercises, experimental subjects cardioaccelerated briefly (mean HR during resistance training, 63.7% HR reserve), whereas control subjects rested briefly (mean HR, 33.5% HR reserve). Mean DOMS among all muscle groups and workouts was discernibly less in experimental than control groups in men (P = 0.0000019) and women (P = 0.0007); less for each muscle group used in nine resistance exercises in both genders, discernible (P < 0.025) in 15 of 18 comparisons; and less in every workout, discernible (P < 0.05) in 32% (men) and 55% (women) of workouts. Most effect sizes were moderate. In both genders, mean DOMS per workout disappeared by the fourth week of training in experimental but not control groups. Aerobic cardioacceleration immediately before each set of resistance exercises therefore rapidly eliminates DOMS during vigorous progressive resistance training in athletes.