The dynamics of yo-yo motion are considered in this article. Many textbooks have examined the "rolling" motion of a yo-yo as it moves vertically up or down. However, in the vicinity of the lowest point, a jerk in the string occurs as the center of mass transitions from a linear motion to a pure rotational motion (with respect to the end…

In this article, the dynamics of a traditional toy, the yo-yo, are investigated theoretically and experimentally using smartphone sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is…

Purpose: This study examined the relationships between the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and resting heart rate variability (HRV) and submaximal 5'-5' test derived measures in novice male soccer players. Methods: Forty players (11.54 [plus or minus] 0.58 years) from a soccer academy participated in this study, performing…

Employing scientific reasoning when giving biological explanations comes easily to the experienced scientist. However, students often encounter difficulty when they attempt to explain biological phenomena. One significant obstacle appears to be the failure or inability to bear in mind the levels of organization. To address this issue, learning…

Many South African schools are underperforming academically and are labelled as trapped or yo-yo schools. The motivation and commitment of school leadership and educators play a critical role in realising improved academic results and sustainable improvement. In the study reported on here a 2-fold perspective was used to explore the problem of…

The main purpose of this study was to examine the relationship between cardiovascular endurance and mental toughness among football players of Academy Mokhtar Dahari (AMD). Twenty players were selected as respondents. Data were collected using Yo-Yo test level 1 and Mental Emotional Bodily Toughness (MeBTough) Questionnaires (Mark, 2008). This…

A popular demonstration involves placing a yo-yo on a level table and gently pulling the string horizontally when it is wrapped to come out below the center of the yo-yo's axis. Students are then asked to predict which way the yo-yo will move. A similar demonstration is performed with a tricycle by pulling forward on a pedal with the pedal down in…

The yo-yo is a scientific toy that has fascinated young and old for thousands of years. According to yo-yo experts, the yo-yo is the second oldest toy in the world, after the doll. Yo-yo activities can be an excellent tool to help students explore many important physics concepts related to energy and motion. The rich history of the yo-yo offers…

Purpose: This study analyzed the physiological response during Yo-Yo Intermittent Recovery Level 1 (YYIR1) test and re-test by in-field ergospirometry and time-series analyses of respiratory parameters. Methods: Ten moderately trained males (23.4 ± 2.01 years, VO[subscript 2peak]= 56.81 ± 10.75 mL·kg[superscript -1]·min[superscript -1]) completed…

Brainstorming is a creativity technique in which a group of people (or an individual person) spontaneously generates a set of ideas to find the solution to a particular problem. This paper describes an innovative approach called "brainstorming with yo-yos," which was implemented in an outreach to high school event to increase high school…

Futsal is a team game with high physical demands of players. Agility, aerobic and anaerobic power outputs of the players support the success in the game. 24 male players attending the Kafkas University having played futsal in the school team for at least one year participated in the study. The players were separated into two groups. The…

There is a danger that transition becomes a concept that aids the official reality of a school or education system to mask the unofficial system difficulties. This article distinguishes four very different understandings of transitions that underpin research in education on this issue. Going beyond a typical systems framework for understanding…

The aim of this study is to compare some physical parameters of professional and regional amateur footballers according to their positions. Totally 100 volunteer football players playing in the professional and regional amateur league participated in the study. Anthropometric measurements (height, body weight, body fat ratio) were performed first…

This paper presents the study of a modern yo-yo having a centrifugal clutch allowing the free rolling. First, the mechanical parts of the yo-yo are measured, allowing us to determine analytically its velocity according to its height of fall. Then, we are more particularly interested in the centrifugal device constituted by springs and small…

The ability of change of direction quickly, in other words agility, and short distance sprinting speed are two of the most important performance components for football referees. The tests used by FIFA and UEFA such as Cooper Test, Yo-Yo Intermittent Test, 40 × 75 m tests do not include testing the agility skills of the referees. However,…