An Exploratory Study on Whether the Interference Effect Occurs When High-Intensity Strength Training Is Performed Prior to High-Intensity Interval Aerobic Training

Abstract

Featured Application: This training regimen can be used as a time-efficient protocol for people with lower levels of aerobic fitness to kickstart their fitness journey. The training loads applied can be used as initial mesocycle loads for untrained participants, noting that, through effective periodization, the HITT intensities will periodically increase to provide an ongoing adaptive stimulus. Further, for aerobically trained individuals (>40 mL/kg/min), we suggest that this program be modified by increasing the prescribed training intensities to induce a sufficient stimulus to increase their baseline strength and aerobic parameters. An alternative use of this intervention is as a short (off-/pre-season) training regimen within sports clubs to boost strength and endurance parameters through a brief, but intense, time-efficient training approach. Finally, the described intervention could be implemented in occupational settings (e.g., fly-in–fly-out work camp labour workers in mines), where the benefit from incorporating a systematic training regimen, especially when the time devoted to exercise is limited, can lead to general health benefits. There is conflicting evidence on whether concurrent aerobic endurance and resistance training (RT) leads to synergistic enhancements in aerobic capacity and muscular strength or causes interference, limiting performance gains. We developed a concurrent training (CT) intervention, including full-body dynamic RT combined with high-intensity interval training (HIIT), on a cycle ergometer to determine whether a brief CT intervention is beneficial to both muscular strength and aerobic capacity. In an exploratory pilot study, participants (n = 10; male = 4) undertook a four-week CT intervention consisting of RT, including six compound movements (bench press, squat, deadlift, Pendley row, squat jumps, and rack pulls), plus cycle HIIT. The pre-/post-intervention improvements were assessed via bench press and leg press 3RM testing, an isometric mid-thigh pull, a countermovement jump, and the change in the relative (Formula presented.) O2max. We observed significant (p < 0.1) increases in the bench press (6.4%), leg press (6.7%), IMTP (11.1%), and relative (Formula presented.) O2max (7%) results. Interestingly, the participants with the highest pre-intervention relative (Formula presented.) O2max demonstrated no performance improvements. These pilot test results suggest that CT is an effective strategy that enables synergistic enhancements that can be observed with very low training volumes. This suggests that CT is an effective strategy for improving muscular strength and aerobic endurance in non-elite physically active individuals.