Background: Concurrent strength and endurance training could interfere with adaptation, which primarily affects long-term strength development. However, so far, research on this theme has rarely focused on ways to optimize concurrent strength and endurance training in team sports. Objectives: This paper aims to summarize the literature on the effects of concurrent training on aerobic and anaerobic energy pathways as well as strength and jump performance measures in team sports (invasion games) to provide recommendations for its application. Methods: A systematic literature review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Various reliable sources with only experimental studies investigating the effect of concurrent training on sport-specific performance measures in team sports (invasion games) were included. Two researchers independently evaluated the risk of bias with the Physiotherapy Evidence Database scale. Results: From 1649 records, 24 were included: 12 in children/adolescents ( n = 428; aged up to 18 years) and 12 in adults ( n = 620; aged 19–30 years), respectively. Thirteen of 24 studies reported improved endurance (V˙O2max, YoYoIR) and strength (CMJ, SJ and 1RM) performance by adding additional resistance training in young and adult team sport players with different training status, and nine of 24 studies reported more pronounced interference effects in older and more experienced players. Discussion: Concurrent training can improve endurance and strength performance in team sports athletes. However, it is revealed that concurrent training can lead to diminished effects, which might be minimized by extended recovery time between sessions, adapted sequencing order and endurance exercise modality. With maturity and developing training status, an increased importance of these variables was documented.

Seipp, D, Feuerbacher, JF, Jacobs, MW, Dragutinovic, B, and Schumann, M. Acute effects of high-intensity interval running on lower-body and upper-body explosive strength and throwing velocity in handball players. J Strength Cond Res 36(11): 3167–3172, 2022—The purpose of this study was to determine the acute effects of handball-specific high-intensity interval training (HIIT) on explosive strength and throwing velocity, after varying periods of recovery. Fourteen highly trained male handball players (age: 25.4 (26.2 ± 4.2) performed HIIT consisting of repeated 15-second shuttle runs at 90% of final running speed (VIFT) to exhaustion. Upper-body and lower-body explosive strength and throwing velocities were measured before and immediately after HIIT, as well as after 6 hours. These tests included 3 repetitions of both bench press and squat exercise at 60% of the 1 repetition maximum (1RM) as well as 3 repetitions of the set shot without run up and jump shot, respectively. Explosive squat performance was significantly reduced at post (−5.48%, p = 0.026) but not at 6 h (−0.24%, p = 1.000). Explosive bench press performance remained statistically unaltered at post (0.32%, p = 1.000) and at 6 hour (1.96%, p = 1.000). This was also observed in the subsequent throws both immediately after (−0.60%, p = 1.000) (−0.31%, p = 1.000) and at 6 h (−1.58%, p = 1.000) (1.51%, p = 0.647). Our data show a reduction in explosive strength of the lower but not upper extremities when preceded by running HIIT. Since throwing velocity was not affected by intense lower-body exercise, combining lower-body HIIT and throwing practice may be of no concern in highly trained handball players.