Table 3.

Selected studies on the chronic effect of dual-tasks.

Authors	Participants	Age	Competitive Level	Dependent Variables	Dual-Tasks Training	Results
Ducrocq et al. [45]	30 amateur table tennis players (25 men and 5 women).	Mean age = 33 years Range = 17–50 Control group: Mean age = 32.46 SD = ±13.60 Training group: Mean age = 34.76 SD = ±13.29	Amateur	Working memory (near task) effectiveness of technical-tactical actions in the tennis task (far task); Quiet eye period; Quiet eye onset and offset.	DT: computer tasks to memorize a visual stimulus + task to memorize an auditory stimulus (letters), simultaneously. Training regimen: 20 blocks of 20 + n (number of letters) attempts. Each training session lasted approximately 30 min and was performed in 10 days.	Working memory: increased score after training Effectiveness of technical-tactical action in the tennis task (far task): increased accuracy after training Quiet Eye Offset: increased fixation after training Quiet Eye Period and onset: no significant differences after training
Fleddermann et al. [21]	43 beach volleyball players, 22 in the intervention group (2 men and 20 women) and 21 in the active control group (5 men and 16 women).	Intervention group: Mean age = 16.38 SD = ±1.7 Control group: Mean age = 21.38 SD = ±4.53	Elite	Working memory capacity; Jump height in a specific task (beach volleyball); Accuracy in 3D Motion task; Attentional capacity; Processing speed	DT: the specific or nonspecific motor task of volleyball + 3D Motion task. Training regimen: Eight weeks with two blocks per week, lasting 30 min per session. Each block comprised three sessions, eight minutes each with a three-minute break in-between.	Performance in the 3D motion task: training group showed higher scores compared with the control group in the post-test Sustained attention: training group showed higher scores compared with the control group in the post-test Processing speed: training group showed higher scores compared with the control group in the post-test Jump height: performance in single tasks was higher than in dual-tasks in the post-test Working memory capacity: no significant difference between groups and time.
Harris et al. [46]	36 hockey and soccer players (22 women and 14 men).	Mean age = 22.5 years SD = ±3.7	Amateur	Working memory capacity; Accuracy in the 3D Motion test (object tracking) Visual search behavior (centroid and amplitude)	3D Motion Training: Multi-object tracking Training regimen: Each session consisted of four blocks of 20 objects for tracking. Each session lasted 20 min. The training group returned for another 20 min of training after 12–14 days.	Accuracy in the 3D Motion task: training group showed a higher score compared with the control group in the post-test Working memory capacity: training group showed a higher score compared with the control group in the post-test Visual behavior: no significant difference between groups.
Romeas et al. [25]	23 male soccer players.	Training group (3D Motion): Mean age = 21.27 SD = ±0.81 Active control: Mean age = 21.39 SD = ±1.03 Passive control: Mean age = 22.48 SD = ±0.71	Amateur	Decision-making performance in small-sided games and passing, dribbling and shooting performance	3D Motion Training: football scenes + decision-making responses. Training regime: two sessions per week over 5 consecutive weeks. Athletes participated in at least 3 out of the 5 sessions of 3D Motion	Only the training group improved the passing decision-making from pre- to post-test. There were no differences in kicking and dribbling.
Romeas et al. [26]	29 badminton players (6 women and 23 men).	Mean age = 22.98 SD = ±2.77 years	Amateur	Speed, reaction time, decision making	Training: 3D Motion training + motor decision-making task and training com 3D Motion + perceptual decision-making task. Training regimen: nine 30-min sessions	The group that trained to combine 3D Motion task + motor decision-making task showed better performance in decision making and reaction time in the post-test moment. The group that trained to combine 3D Motion task + perceptual decision-making task did not improve performance in any of the variables.

DT: Dual-Task.