Search Results

You are looking at 1 - 3 of 3 items for

  • Author: Harm Kuipers x
Clear All Modify Search
Restricted access

Jantine Slinger, Eric van Breda and Harm Kuipers

The article presents the current performance capacity in 11–15 year old Dutch adolescents who participated in an incremental cycle test (n = 509) and or in a shuttle run test (N = 1,198). Cycle test results increased significantly with age in both genders, also after normalization to body weight. Shuttle run test results increased significantly with age only in boys. Compared with previous data, the absolute performance capacity in the cycle tests was comparable to data from 15 years ago, whereas the performance capacity normalized to kg body weight and the shuttle run test results seem to be fairly lower compared with the former data.

Restricted access

Zandrie Hofman, Harm Kuipers, Hans A. Keizer, Erik J. Fransen and Roderique C.J. Servais

This investigation examined the plasma glucose and insulin response in 6 trained athletes after consumption of four commercially available sport feedings 2 hr before as well as immediately after 1 hr of running under common training conditions. Four feedings were compared: Feeding 1, 160 g CHO/400 ml; Feeding 2, 69 g CHO/400 ml; Feeding 3, 69 g CHO + 6 g protein/400 ml; and Feeding 4, solid 69 g CHO + 5 g protein + 4 g fat. Before the training session, there were no differences between the four sport feedings in the area under the glucose and insulin curves and the insulin/glucose ratio. However, after exercise, Feeding 2 resulted in a significantly greater area under the glucose curve compared with Feedings 1, 3, and 4 (respectively, 352 vs. 241, 251, and 182) and a significantly lower insulin/glucose ratio compared with Feeding 1 (respectively, 6.2 vs. 15.8). Therefore, it is concluded that the kind of sport feeding may influence postexercise glucose and insulin responses.

Restricted access

Robert van Cingel, Gertjan Kleinrensink, Rob Stoeckart, Geert Aufdemkampe, Rob de Bie and Harm Kuipers

Objective:

To determine concentric shoulder external-internal rotator strength, dominant and non-dominant shoulder differences and agonist/antagonist ratios.

Design:

A transversal study of isokinetic dynamometry of healthy shoulders, 95% confidence intervals are presented.

Participants:

35 asymptomatic elite, male volleyball players.

Measurements:

Peak torque normalized for body weight was recorded at 60, 180, and 300°/sec. with a Cybex 6000 dynamometer.

Results:

(1) internal rotators were significantly stronger than external rotators of the same shoulder; (2) internal rotators of the dominant arm were significantly stronger than of the non-dominant arm; (3) no difference existed between external rotators of the dominant and the non-dominant arm; (4) external–internal rotator ratios of the dominant arm were significantly lower than of the non-dominant arm; and (5) no differences were found between the ratios of each arm separately.

Conclusions:

Data presented are important for interpreting isokinetic shoulder rotator strength tests in elite volleyball players and could be relevant in rehabilitation and prevention of shoulder injuries.