Search Results

You are looking at 21 - 30 of 827 items for :

  • "progression" x
Clear All
Restricted access

Susana Meireles, Neil D. Reeves, Richard K. Jones, Colin R. Smith, Darryl G. Thelen and Ilse Jonkers

been deeply explored in OA with most studies in literature focusing on knee loading during level walking as a biomarker for OA onset and progression. Previous literature has shown reduced knee flexion moments (KFM), 4 , 7 , 9 nonconclusive findings in knee adduction moments (KAM), 4 , 10 and altered

Restricted access

Jac Orie, Nico Hofman, Jos J. de Koning and Carl Foster

During the last decade discussion about training-intensity distribution has been an important issue in sports science. Training-intensity distribution has not been adequately investigated in speed skating, a unique activity requiring both high power and high endurance.

Purpose:

To quantify the training-intensity distribution and training hours of successful Olympic speed skaters over 10 Olympiads.

Methods:

Olympic-medal-winning trainers/coaches and speed skaters were interviewed and their training programs were analyzed. Each program was qualified and quantified: workout type (specific and nonspecific) and training zones (zone 1 ≤2 mMol/L lactate, zone 2 2–4 mMol/L lactate, zone 3 lactate >4 mMol/L). Net training times were calculated.

Results:

The relation between total training hours and time (successive Olympiads) was not progressive (r = .51, P > .5). A strong positive linear relation (r = .96, P < .01) was found between training distribution in zone 1 and time. Zones 2 and 3 both showed a strong negative linear relation to time (r = –.94, P < .01; r = –.97, P < .01). No significant relation was found between speed skating hours and time (r = –.11, P > .05). This was also the case for inline skating and time (r = –.86, P > .05).

Conclusions:

These data indicate that in speed skating there was a shift toward polarized training over the last 38 y. This shift seems to be the most important factor in the development of Olympic speed skaters. Surprisingly there was no relation found between training hours, skating hours, and time.

Restricted access

Martin A. Fees

Restricted access

Rita M. Malcata, Tom J. Vandenbogaerde and Will G. Hopkins

There is a need for fair measures of country sport performance that include athletes who do not win medals.

Purpose:

To develop a measure of country performance based on athlete ranks in the sport of swimming.

Methods:

Annual top-150 ranks in Olympic pool-swimming events were downloaded for 1990 through 2011. For each athlete of a given rank, a score representing the athlete’s performance potential was estimated as the proportion of athletes of that rank who ever achieved top rank. A country’s scores were calculated by summing its athletes’ scores over all 32 events. Reliability and convergent validity were assessed via year-to-year correlations and correlations with medal counts at major competitions. The method was also applied to ranks at the 2012 Olympics to evaluate countries’ swimming performance.

Results:

The performance score of an athlete of a given rank was closely approximated by 1/rank. This simpler score has 1 practical interpretation: An athlete ranked 7th (for example) has a chance of 1/7 of ever achieving top rank; for purposes of evaluating country performance, 7 such athletes are equivalent to 1 athlete of the top rank. Country scores obtained by summing 1/rank of the country’s athletes had high reliability and validity. This approach produced scores for 168 countries at the Olympics, whereas only 17 countries won medals.

Conclusions:

The authors used the sport of swimming to develop a fair and inclusive measure representing a country’s performance potential. This measure should be suitable for assessing countries in any sports with world rankings or with athletes at major competitions.

Restricted access

James G. Hay

There have been few attempts to synthesize the knowledge gleaned from the study of cyclic human locomotion and, specifically, to determine whether there are general laws that describe or govern all such forms of locomotion. The purpose of this paper was to test the hypothesis that, when a human participant performs multiple trials of a given form of cyclic locomotion at a wide range of speeds (S) and without constraint on cycle rate (CR) or cycle length (CL), the relationships of CR vs. S and CL vs. S have the same basic characteristics as do those for any other form of cyclic locomotion. Data were gathered from published and unpublished sources. For each participant and form of locomotion, CR-vs.-S and CL-vs.-S relationships were plotted on a common scattergram with S on the abscissa and both CR and CL on the ordinate. Analysis of data collected on 49 participants and 12 forms of locomotion showed that, for every combination of participant and form of locomotion considered (excluding combinations involving simulated locomotion), the relationships of CR vs. S and CL vs. S had the same basic characteristics. These relationships were quadratic in form with CR-vs.-S concave upward and CL-vs.-S concave downward. The factor that made the greater contribution to increases in S was a function of S, with CL the primary factor at low S and CR the primary factor at high S. In short, the results obtained provided unequivocal support for the hypothesis of the study. The basic CR-vs.-S and CL-vs.-S relationships observed for forms of actual locomotion were also observed for some, but not all, of the forms of simulated locomotion examined.

Restricted access

Jan Bourgois, Adelheid Steyaert and Jan Boone

Purpose:

In this case study, a world-class rower was followed over a period of 15 y in which he evolved from junior to professional athlete.

Methods:

An incremental exercise test and a 2000-m ergometer test were performed each year in the peak period of the season starting at the age of 16 y. In addition, the training logs of 1 y each as a junior and a senior rower were recorded and analyzed.

Results:

Maximal oxygen uptake (VO2max), maximal power output (Pmax), and power output at 4 mmol/L blood lactate concentration increased until the age of 27 and then stabilized at 30 y at 6.0 ± 0.2 L/min, 536 ± 15 W, and 404 ± 22 W, respectively. At the age of 27–28 y the rower also had a career-best 2000-m ergometer test (5′58″) and on-water performance with a 4th place at the Olympic Games (2008) in Beijing and World Championships (2009). At the age of 23 y, the rower trained a total of 6091 km in 48 wk. Of the total training time, 15.4% consisted of general training practices, 23.4% resistance training, and 61.2% specific rowing training.

Conclusion:

The on-water performance in the World Championships and Olympic Games corresponded closely to the evolution in the rower’s physiological profile and 2000-m ergometer performance. The long-term build-up program resulted in an increase in the physiological parameters up to the age of 27 y and resulted in a 4th position at the 2008 Olympic Games at a body mass of only 86 kg.

Restricted access

Henrik Koblauch, Thomas Heilskov-Hansen, Tine Alkjær, Erik B. Simonsen and Marius Henriksen

It is unclear how rotations of the lower limb affect the knee joint compression forces during walking. Increases in the frontal plane knee moment have been reported when walking with internally rotated feet and a decrease when walking with externally rotated feet. The aim of this study was to investigate the knee joint compressive forces during walking with internal, external and normal foot rotation and to determine if the frontal plane knee joint moment is an adequate surrogate for the compression forces in the medial and lateral knee joint compartments under such gait modifications. Ten healthy males walked at a fixed speed of 4.5 km/h under three conditions: Normal walking, internally rotated and externally rotated. All gait trials were recorded by six infrared cameras. Net joint moments were calculated by 3D inverse dynamics. The results revealed that the medial knee joint compartment compression force increased during external foot rotation and the lateral knee joint compartment compression force increased during internal foot rotation. The increases in joint loads may be a result of increased knee flexion angles. Further, these data suggest that the frontal plane knee joint moment is not a valid surrogate measure for knee joint compression forces but rather indicates the medial-to-lateral load distribution.

Restricted access

Iñigo Mujika, Luis Villanueva, Marijke Welvaert and David B. Pyne

each swimmer’s season best and their last time swum at the major event was calculated for all women’s and men’s events of the Olympic and World Championships program, for a total of 4728 observations. The criterion for performance progression, no change, or regression was ΔPerf being lower, equal, or

Restricted access

Brandon C. Platt, Sue Falsone and Kenneth C. Lam,

the right inferior hemiscrotum and the patient was taken to recovery in stable condition. Comparative Outcomes The patient returned to competition following a return-to-play progression designed by the physician and athletic trainer (Table  2 ). After 13 days of rest, the patient completed a day of

Restricted access

Xavier D. Thompson and Brianna DiAntonio

The high rate of injury and re-injury, as well as the challenge of returning patients to activity, must all be considered postinjury. There is a dearth of research regarding ACL injuries and return to play in track and field athletes. This case report examines the return-to-play progression of a short