INTRODUCTION

A person constantly upgrades various processes in order to reach the desired goal in a short and high-quality way. Physical culture and sports are no exception. Athletes and coaches are always in search of exercises from which the body gets its useful maximum. One of the modern and popular physical exercises all over the world is «Burpee». The author of the exercise is an American physiologist from New York, Royal Nadleston Burpee, who invented it in the early 1930s. Today, the «Burpee» exercise is so popular that online challenges are being held on the Internet in which participants compete for the maximum number of repetitions. «Burpee» is a functional exercise that accelerates the work of the heartbeat and at the same time a fairly large group of muscles is involved in it: shoulders, biceps, pectoral muscles, abdominals, back muscles, gluteal muscles, quadriceps thighs. The indisputable advantage of the «Burpee» exercise is the ability to perform it anywhere without the presence of special sports equipment and a trainer. Athletes who practice CrossFit have long appreciated the benefits and high efficiency of «Burpee», while the exercise has a lot of modifications. It can be performed both in light conditions and in complicated ones [1, 2].

The «Burpee» exercise can be effective for the safe development of the muscles of adolescents, as they work with their own weight. Strength training with barbells and dumbbells in adolescence is not recommended because it can harm a person’s growth and development. However, for the correct and intensive performance of the «Burpee» exercise, a large amount of effort and a good level of physical fitness is required. At the proper level, most physical qualities should be developed. Taking into account the sensitive periods of development of such physical qualities as strength, speed-strength abilities, and endurance, the age of 15-16 years was determined for the study, this is the 9th grade in a regular school. At this age, there is a rather intensive development of the muscle mass of schoolchildren, a favorable development of most physical qualities, especially endurance [3, 4].

If at primary school age a differentiated approach and coordination training prevail, then at senior school age an individual approach is more often used. Even though the «Burpee» exercise is quite popular all over the world, we were unable to find scientific studies that show effective components of physical activity for schoolchildren. In all likelihood, such an activity will be more effective individually for each student [5, 6].

In addition, some studies have proven the effective influence of physical activity on the indicators of mental processes in children of different ages. This is especially important at the age of 15-16 since, after the end of the 9th grade, children go to colleges or the 10th grade [7-9].

Purpose – To determine the influence of the «Burpee» exercise on the indicators of endurance and distribution of attention in children aged 15-16.

Research hypothesis: it is assumed that if schoolchildren 15-16 years old use the physical exercise «Burpee» at every physical education lesson at school, then not only endurance indicators will improve, but also the distribution of attention indicators.

MATERIALS AND METHODS

Participants

Schoolchildren 15-16 years old, who studied at a regular Russian school in the city of Kirov, took part in the pedagogical experiment. In total, 52 schoolchildren took part in the study, these are boys and girls who studied in grades 9a and 9b. This served as the distribution of schoolchildren into the control group (CG) and the experimental group (EG). Regardless of gender and level of physical fitness, only those schoolchildren who were admitted to physical education lessons by a doctor without any restrictions for health reasons took part in the study. In total, 32 students studied in grade 9a (CG), but 25 people (13 boys and 12 girls) were admitted to the study and were completely healthy. There were 33 students in the 9b grade (EG), but 27 students (13 boys and 14 girls) took part in the study.

Procedure

The pedagogical experiment was conducted from September 1 to December 30, 2021, at a comprehensive school in the city of Kirov, Russia. All physical education lessons at the school were held 2 times a week for 45 minutes each lesson. During the period of the pedagogical experiment, 30 physical education lessons were held in each class; for 4 months, schoolchildren went to a physical education lesson at the same time. Children from grade 9a had their second lesson on Tuesday and the first lesson on Thursday. Children from grade 9b studied the first lesson on Tuesday and the second lesson on Thursday.

Schoolchildren from the CG (9a) were engaged in the usual physical education program at the school for students in grades 1-11 [10].

Schoolchildren from the EG (9b) studied according to the same program, but additionally performed the «Burpee» exercise at each lesson.

Execution Technique

If we decompose the whole exercise in stages, then it consists of simpler exercises: squats, planks, push-ups, and jumping out. The technique of the traditional exercise «Burpee»:

1. Starting position - stand up straight, feet shoulder-width apart.
2. Bend your knees and, in a squat position, rest your hands on the floor. Shift body weight onto hands.
3. Jump out with your feet back so that you are in a plank position with straight arms.
4. Do one push-up (flexion and extension of the arms in a lying position) and return to the plank position.
5. Jump to pull your legs to your hands and be in a squat position.
6. Jump up, raise your arms and clap above your head.

It is important to focus on the correct technique for performing the exercise, and not on the number of repetitions. However, to achieve the effect, it is necessary to maintain a sufficiently high intensity of the exercise.

Contraindications

With extreme caution, the «Burpee» exercise should be performed in some cases:

• joint problems, especially with the knee and hip;
• chronic heart disease or high blood pressure;
• excessive overweight (more than 30% of the normal weight);

It is important to ensure that when performing the «Burpee» exercise, conditions such as dizziness, nausea, and chest pain do not appear. In such cases, the exercise should be stopped.

Exercise Stress

The components of physical activity were individual since each student had his own level of physical fitness. The exercise was performed for time, without counting the repetitions of each student and the teacher's mental count. Over a period of time, students performed varying amounts of repetitions (approximately 15 to 25 repetitions per minute).

Depending on the objectives of the lesson, the exercise was performed either after the warm-up or at the end of the main part of the lesson. At the same time, of course, we were guided by the principle of gradualism. The physical activity components of the «Burpee» exercise are presented in Table 1.

It should be noted that the activity was selected according to the well-being of the majority of children in the class. So, for example, the exercise «Burpee» performed less than 60 seconds will be ineffective, however, if it is performed in the first month for more than 60 seconds, then most of the students will stop. Gradually, the activity increased, and the rest time decreased. More than three series with sufficiently high intensity, most of the students physically could not endure. At the same time, the «Burpee» exercise needed not interfere with the implementation of the main physical education curriculum at school.

Before and after the start of the study, all children took two control tests:

1. General endurance was determined according to the test «Running 2000 m» [10].

Procedure

Running 2 km on the treadmill of the athletics arena. The test was performed from a high start position. At the command «Start!» students take their places in front of the start line. After the command «March!» they start running.

The result is recorded by the chronometer in minutes and seconds with an accuracy of 1 second.

2. Distribution of attention was determined according to the test «Different counts» [11].

Procedure: At the teacher’s signal, the schoolchildren should write down the numbers from 1 to 20 as quickly as possible, and at the same time call the numbers out loud in reverse order, that is, from 20 to 1. The result is the time spent on the test (s).

Mathematical and Statistical Processing of Results

The indicators of all participants were recorded in a Microsoft Excel spreadsheet, and the mean value and standard deviation were determined. The change in the indicators of schoolchildren from the beginning to the end of the study was determined as a percentage, and the significance of the values was determined by Student’s T-test (p>0.05).

RESULTS AND DISCUSSION

Before the start of the pedagogical experiment and after its completion, all students took control tests. The results are presented in Table 2.