Tribute to Dr Jacques Rogge: muscle activity and fatigue during hiking in Olympic dinghy sailing

‘A tribute to Dr J. Rogge’ aims to systematically review muscle activity and muscle fatigue during sustained submaximal quasi-isometric knee extension exercise (hiking) related to Olympic dinghy sailing as a tribute to Dr Rogge’s merits in the world of sports. Dr Jacques Rogge is not only the former President of the International Olympic Committee, he was also an orthopaedic surgeon and a keen sailor, competing at three Olympic Games. In 1972, in fulfilment of the requirements for the degree of Master in Sports Medicine, he was the first who studied a sailors’ muscle activity by means of invasive needle electromyography (EMG) during a specific sailing technique (hiking) on a self-constructed sailing ergometer. Hiking is a bilateral and multi-joint submaximal quasi-isometric movement which dinghy sailors use to optimize boat speed and to prevent the boat from capsizing. Large stresses are generated in the anterior muscles that cross the knee and hip joint, mainly employing the quadriceps at an intensity of 30–40% maximal voluntary contraction (MVC), sometimes exceeding 100% MVC. Better sailing level is partially determined by a lower rate of neuromuscular fatigue during hiking and for ≈60% predicted by a higher maximal isometric quadriceps strength. Although useful in exercise testing, prediction of hiking endurance capacity based on the changes in surface EMG in thigh and trunk muscles during a hiking maintenance task is not reliable. This could probably be explained by the varying exercise intensity and joint angles, and the great number of muscles and joints involved in hiking.

Highlights

• Dr Jacques Rogge, former president of the International Olympic Committee and Olympic Finn sailor, was the first to study muscle activity during sailing using invasive needle EMG to obtain his Master degree in Sports Medicine at the Ghent University.

• Hiking is a critical bilateral and multi-joint movement during dinghy racing, accounting for >60% of the total upwind leg time. Hiking generates large stresses in the anterior muscles that cross the knee and hip joint.

• Hiking is considered as a quasi-isometric bilateral knee extension exercise. Muscle activity measurements during sailing, recorded by means of EMG, show a mean contraction intensity of 30-40% maximal voluntary contraction with peaks exceeding 100%.

• Hiking performance is strongly related to the development of neuromuscular fatigue in the quadriceps muscle. Since maximal strength is an important determinant of neuromuscular fatigue during hiking, combined strength and endurance training should be incorporated in the training program of dinghy sailors.

     

Evaluating quality of implementation in physical activity interventions based on theories of motivation: current challenges and future directions

The evidence base pointing towards the maladaptive health consequences of an inactive lifestyle highlights the need for interventions that are effective in changing and maintaining physical activity behaviours. Theories of motivation are frequently applied to inform the content and delivery of such interventions. Systematic monitoring and evaluation of the quality of intervention implementation is therefore an important step in understanding if and how theories of motivation can be adopted and effectively applied to promote and/or sustain physical activity behaviours. However, intervention implementation quality in studies that aim to apply motivation theory to promote physical activity is often under-reported. The purpose of this article is, first, to review contemporary approaches used to monitor and evaluate intervention implementation; we outline the degree to which these methods have been used effectively in research concerned with applying theories of motivation to impact physical activity behaviours. Second, we identify and discuss specific challenges in effectively measuring quality of implementation faced by researchers who adopt a motivation theory basis to their work. Finally, recommendations for methods to monitor and evaluate intervention implementation in future trials aiming to promote physical activity based on theories of motivation are also proposed.     

Hot and Cool Self-Regulation,Academic Competence,and Maladjustment: Mediating and Differential Relations

This study examined differential and mediating relations between hot and cool self-regulation (M_age = 48.2 months; N = 1,155, 48% girls), first-grade (M_age = 77.5 months) maladjustment (externalizing [EXT] and internalizing [INT] behavior), and first- and second-grade (M_age = 89.5 months) academic competence (AC). Using teacher reported EXT, INT, and AC, partial support for the differential perspective was found in that only hot self-regulation was significantly related to EXT, whereas both hot and cool self-regulation was significantly related to AC. Moreover, hot self-regulation indirectly predicted second-grade AC through first-grade EXT, lending some support for the mediating perspective also. The findings contribute to an understanding of how self-regulation is related to academic and behavioral school adjustment.     

Relationships between anthropometric measures and athletic performance,with special reference to repeated-sprint ability,in the Qatar national soccer team

Abstract

The aim of this study was to determine potential relationships between anthropometric parameters and athletic performance with special consideration to repeated-sprint ability (RSA). Sixteen players of the senior male Qatar national soccer team performed a series of anthropometric and physical tests including countermovement jumps without (CMJ) and with free arms (CMJwA), straight-line 20 m sprint, RSA (6 × 35 m with 10 s recovery) and incremental field test. Significant (P < 0.05) relationships occurred between muscle-to-bone ratio and both CMJs height (r ranging from 0.56 to 0.69) as well as with all RSA-related variables (r < –0.53 for sprinting times and r = 0.54 for maximal sprinting speed) with the exception of the sprint decrement score (S_dec). The sum of six skinfolds and adipose mass index were largely correlated with S_dec (r = 0.68, P < 0.01 and r = 0.55, P < 0.05, respectively) but not with total time (TT, r = 0.44 and 0.33, P > 0.05, respectively) or any standard athletic tests. Multiple regression analyses indicated that muscular cross-sectional area for mid-thigh, adipose index, straight-line 20 m time, maximal sprinting speed and CMJwA are the strongest predictors of S_dec (r² = 0.89) and TT (r² = 0.95) during our RSA test. In the Qatar national soccer team, players’ power-related qualities and RSA are associated with a high muscular profile and a low adiposity. This supports the relevance of explosive power for the soccer players and the larger importance of neuromuscular qualities determining the RSA.     

Development and validation of the Perceived Game-Specific Soccer Competence Scale

ABSTRACT

The objective of this study was to create a valid, self-reported, game-specific soccer competence scale. A structural model of perceived competence, performance measures and motivation was tested as the basis for the scale. A total of 1321 soccer players (261 females, 1060 males) ranging from 12 to 15 years (13.4 ± 1.0 years) participated in the study. They completed the Perceived Game-Specific Soccer Competence Scale (PGSSCS), self-assessments of tactical skills and motivation, as well as technical and speed and agility tests. Results of factor analyses, tests of internal consistency and correlations between PGSSCS subscales, performance measures and motivation supported the reliability and validity of the PGSSCS. The scale can be considered a suitable instrument to assess perceived game-specific competence among young soccer players.     

Functional reading difficulties in Denmark

In this first Danish study of adult reading skills, 1124 adults between 18 and 67 years of age participated in an interview about reading habits and skills, and 445 were tested individually at home using six common texts. Great care was taken to ascertain that subjects were representative of the whole adult population and that the texts covered most types of everyday reading. Three percent of the participants were found to have severe functional reading difficulties and a further 9 percent to have moderate difficulties. Regression analyses found several unique predictors of reading difficulties: age (adults over 45 years reading more poorly than younger adults), limited basic education, no vocational training nor higher education, and a small amount of reading needed at work. The rate of poor readers was about four times higher among persons with low income than among others. Men and women read equally well although men tended to rate themselves lower as readers than women did. Methodological issues and some educational implications are discussed.     

‘Children’s clans’; social organisation and interpretive reconstruction as aspects on development of peer-groups in outdoor play

The focus of this article is children’s self-organisation of peer-groups through play. The play was initiated by encounters with the environment. The use of ethnographic methods in early childhood research has proved helpful to elucidate, interpret, and understand children’s experiences and the creation of meaning in their everyday lives. This inquiry draws on field notes, informal conversations with the children, and photos from a study of kindergarten children’s experiences of outdoor places and landscapes in Norway. Going out of doors together with the children regularly over a period of 10 months revealed aspects of how children’s interactions in play connect to their use of natural landscapes and its place in peer-group social organisation. The data are presented as ‘narrative maps’ and episodes written as ‘emplotted’ narratives.     

Eye-movement parameters and reading speed

This study addressed the relationship between four eyemovement parameters and reading speed of 20twelve-year-old children during silent and oralreading. The results indicated that each of theparameters correlated significantly with speed ofsilent reading. In fact, reading speed could bepredicted by the following variables: recognitionspan, average fixation duration, and number ofregressive saccades. Moreover, the relationshipbetween silent and oral reading speed, on one hand,and between reading fluency and reading errors in oralreading speed, on the other, was examined. The resultsindicated that in terms of reading speed, significantinterrelationships existed between silent and oralreading. Furthermore, fluency and errors wereintercorrelated phenomena, but only fluency wassubstantially related to oral reading speed.     

Is the Simple View of Reading too Simple?

According to the Simple View of Reading (SVR), reading comprehension is the product of word decoding ability and linguistic comprehension (R = D × C). However, there is also evidence showing that an additive model (R = D + C) explains just as much or even more of the variance in reading comprehension than the product model. To further evaluate these models, 467 Norwegian students in grade 6 were administered measures of reading comprehension, decoding ability, listening comprehension, phonemic awareness, and rapid digit naming. Hierarchical regression analyses were conducted to evaluate the explanatory power of each model, in addition to the influence of phonemic awareness and rapid naming. The preliminary hierarchical regression analyses were replicated among Swedish students. According to the present study, the additive model explained more of the variance in reading comprehension than the product model, and only rapid naming contributed significantly to explain variance in reading comprehension, above and beyond that explained by the SVR.