Abstract
BACKGROUND: Combined cognitive and exercise training improves exercise endurance, including submaximal muscular endurance. Its effects on maximal muscular strength have yet to be determined. Accordingly, we tested the effects of combined training on muscular strength (one repetition maximum, 1RM) and endurance (as many repetitions as possible, AMRAP). METHODS: Resistance-trained adults (five males, three females) completed ten sessions (four testing, six training) over 4 weeks. In each testing session, they were assessed for bench press 1RM before they completed AMRAP at 50% of initial 1RM. In each training session, they performed five bench press sets (five repetitions at 80% current 1RM), with each set followed by a hard 5 min cognitive task (Time-Load Dual-Back or Color Multi-Source Interference). Ratings of perceived exertion (RPE) were averaged to provide a session RPE. At the end of each session, participants completed a Psychomotor Fatigue Threshold Test and rated mental fatigue. RESULTS: ANOVAs (four testing sessions) showed that combined training increased 1RM (p < 0.001; averaging 8.0 kg or 11% from sessions 1-4) and AMRAP (p < 0.01; 5.1 repetitions or 22%). Moreover, training increased RPE (p < 0.05; 0.3 or 5%) and decreased mental fatigue ratings (p < 0.001; -1.2 or -49%) but did not affect Psychomotor Fatigue Threshold Test reaction times (p > 0.05; 2 ms or 0%). CONCLUSIONS: A 4-week training program that combined high-intensity cognitive and resistance exercise tasks improved maximal and submaximal resistance exercise performance. This pilot study provides preliminary evidence that high-intensity combined training can enhance muscular strength and endurance.