This study examines the differences between expert and novice team‐handball players in their sensitivity to instructions that emphasize speed or precision requirements. The effects of instructions on throwing speed and accuracy of a handball over arm throw and the speed–accuracy trade‐off in experts and novices is revisited. An expert group (n=18) with a training experience of more than 10 years, and a novice group (n=24) without experience in team‐handball, took part in the study. The participants were asked to throw to targets located at different positions following instructions emphasizing accuracy and instructions emphasizing accuracy and speed. Throwing speed was measured with a speed gun radar, and the centre of the ball when the ball entered the goal was digitalized for accuracy. Under these experimental conditions, the novice group was sensitive to instructions for reducing throwing speed and increasing accuracy when instructions emphasized accuracy. The expert group increased throwing speed when the instructions emphasized speed, but was not less accurate. The results indicate that it is advisable for experts’ speed to be close to maximum speed since it does not seem to have a significant effect on accuracy of the throw.

To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects’ individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

This study investigated simultaneous treatments in contextual interference (blocked and random practice) and their effect on the process of learning four tennis shots. 8 tennis players participated in the research, which was carried out in two phases. The first phase involved a 3-wk. period of 12 sessions with 192 practice tennis shots per session for each tennis player. The second phase comprised 4 retention tests carried out at 48 hr. and 2, 4, and 6 weeks following the learning phase. This phase consisted of evaluating the retention of the skills that had been practiced during the learning phase. The results indicated an improvement in the quality of shots for both practice conditions during the learning phase. Differences in retention appeared relative to differences in the type of practice conditions (random or blocked) in which the skill was learned and also depended on the type of shot and the time that had elapsed since the learning period.