title: Interaction between concurrent strength and endurance training.
abstract: To assess the effects of concurrent strength (S) and endurance (E) training on S and E development, one group (4 young men and 4 young women) trained one leg for S and the other leg for S and E (S+E). A second group (4 men, 4 women) trained one leg for E and the other leg for E and S (E+S). E training consisted of five 3-min bouts on a cycle ergometer at a power output corresponding to that requiring 90-100% of oxygen uptake during maximal exercise (VO2 max). S training consisted of six sets of 15-20 repetitions with the heaviest possible weight on a leg press (combined hip and knee extension) weight machine. Training was done 3 days/wk for 22 wk. Needle biopsy samples from vastus lateralis were taken before and after training and were examined for histochemical, biochemical, and ultrastructural adaptations. The nominal S and E training programs were "hybrids", having more similarities as training stimuli than differences; thus S made increases (P less than 0.05) similar to those of S+E in E-related measures of VO2max (S, S+E: 8%, 8%), repetitions with the pretraining maximal single leg press lift [1 repetition maximum (RM)] (27%, 24%), and percent of slow-twitch fibers (15%, 8%); and S made significant, although smaller, increases in repetitions with 80% 1 RM (81%, 152%) and citrate synthase (CS) activity (22%, 51%). Similarly, E increased knee extensor area [computed tomography (CT) scans] as much as E+S (14%, 21%) and made significant, although smaller, increases in leg press 1 RM (20%, 34%) and thigh girth (3.4%, 4.8%). When a presumably stronger stimulus for an adaptation was added to a weaker one, some additive effects occurred (i.e., increases in 1 RM and thigh girth that were greater in E+S than E; increases in CS activity and repetitions with 80% 1 RM that were greater in S+E than S). When a weaker, although effective, stimulus was added to a stronger one, addition generally did not occur. Concurrent S and E training did not interfere with S or E development in comparison to S or E training alone.
authors.affiliation: Department of Physical Education, McMaster University, Hamilton, Ontario, Canada.
authors.forename: D G
authors.initials: DG
authors.lastname: Sale
authors.forename: J D
authors.initials: JD
authors.lastname: MacDougall
authors.forename: I
authors.initials: I
authors.lastname: Jacobs
authors.forename: S
authors.initials: S
authors.lastname: Garner
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D009132:Muscles / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology*; D013848:Thigh / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed