Different-day and same-session combined strength and endurance training : adaptations in neuromuscular and cardiorespiratory performance, body composition, metabolic health and wellbeing in men and women

Abstract

This thesis investigated 1) acute neuromuscular and hormonal responses to combined strength and endurance loadings with different orders and their long-term adaptations (women), 2) adaptations in neuromuscular, hormonal, cardiorespiratory and health variables following 24 weeks of volume-equated protocols of combined training (men and women). Subjects were assigned to one of three groups: strength and endurance training on different days (DD: men n=21, women n=18), training in the same-session with either endurance before strength (ES: men n=16, women n=15) or vice versa (SE: men n=18, women n=14). DD trained 4-6 d·wk-1 with strength and endurance on alternating days. ES and SE trained 2-3 d·wk-1 of [1E+1S] or [1S+1E] with strength and endurance in immediate succession. Training consisted of endurance cycling and hypertrophic and maximal strength training. Both ES and SE led to significant acute neuromuscular fatigue. Post-exercise growth hormone concentrations were significantly larger in SE than ES before and after the intervention. All three groups improvedd strength and endurance performance. The increase in maximal oxygen uptake was significantly larger in DD than in ES and SE in both genders. DD and SE increased voluntary muscle activation while ES did not. The individual changes in voluntary activation and maximal knee extension force were correlated in ES during weeks 13-24. Lean mass and vastus lateralis (VL) cross-sectional area increased similarly in all groups. Decreased fat mass was observed only following DD-training. Changes in blood lipids and abdominal fat were correlated in DD and the entire subject sample. Self-esteem and wellbeing improved and time-management behavior deteriorated in DD, but remained unchanged in the same-session groups. The results suggest that increased physical performance and muscle hypertrophy can be achieved with any of the training modes in previously untrained adults. Individuals adhering to ES training may be susceptible to neural interference, although it is unclear if strength development is affected. DD training simultaneously optimizes body composition and physical performance. DD-training does not result in a feeling of excessive general fatigue despite requiring more individual weekly training sessions than ES and SE.