The Counter Movement Jump (CMJ) test described by Bosco 1,2 is used to evaluate the characteristics of metabolic process in muscle endurance, over a period that can vary from 5 to 60 s. For its execution, CMJ has to be performed continuously during the time set. Recent studies 3 have proven the reliability and validity of the CMJ repeated jumps test to assess anaerobic performance.

The scientific evidences say that physical condition is partly genetically determined, but may also be influenced greatly by environmental factors such as place of residence. 4 Many studies have examined the association between place of residences (Urban and Rural) and physical condition in children and adolescents around the world, as is the case of studies with subjects from the USA, 5 Mexico, 6 Taiwan, 7 Spain 2 and Turkey. 8 Although in none of these studies the place of residence Coast or Interior has been taken into account, nor the exclusive performance of a single type of test.

There are authors who have already undertaken studies on the CMJ test at the age of adolescence 9 finding significant differences between sexes from the age of 14 onwards, not finding scientific evidence of this same study compared to the place of residence.

Also, there is scientific evidence that anaerobic parameters such as maximum anaerobic power or anaerobic resistance are negatively correlated with Body Mass Index (BMI), and the Percentage of Fat in adolescents who regularly practice sport. 10

Moreover, the level of fitness is directly associated with the outcomes related to health during childhood and adolescence. 11,12 And appropriate physical activity is a major determinant of fitness in children and adolescents. 13,14 So, we can say that adolescence is a critical period for the onset of obesity 15 and the morbidity associated with obesity in adulthood. 16

We have determined to execute the CMJ repeated jumps test over 10 s, which we have referred to in this article as (J10s); with this measurement we intend to find alactic anaerobic parameters. 17 And the CMJ repeated jumps test over 60 s, which we have referred to as (J60s), to find thus lactic anaerobic parameters. 17 This last test highlights the developmental capacities of lactic anaerobic power, mechanical power and resistance power to fatigue. 2

318 Andalusian adolescents participated in the study, 182 teenage boys (15.16 ± 1.36 years, 170.7 ± 7.7 cm, 65.81 ± 14.68 kg) and 136 teenage girls (15.07 ± 1.33 years, 161.1 ± 5.4 cm, 55.96 ± 9.74 kg), aged from 13 to 18 years, from seven Secondary Education Institutes spread over the provinces of Granada, Malaga, Cordoba and Almeria. The descriptive results of the sample and the variables measured for both sexes can be seen in (Table 1).

As a criterion of exclusion in the study, the presence of cardiovascular chronic diseases or musculoskeletal injury risk was established. Centers were selected in such a way that they would have a wide sample of subjects whose place of residence was very different (2 centers in Urban – Interior environments, 3 in Rural – Interior and 2 in Urban – Coast). The study was approved by the Committee of Ethics of Human Research of the University of Granada, according to the code of ethics of the World Medical Association (Declaration of Helsinki). A letter of consent was given to all participants and/or tutors, in the same way, prior to the completion of the measurements a letter of information was given to the centre's school council.

The measurements were made on two consecutive days in each center. During these days, a room at a temperature of 20 ± 2 °C was ensured so that the measurements were as consistent as possible, also measurements took place at midday (13–15 h), to rule out a possible effect of heart rate on performance. 11 Once their body composition was analyzed the procedure was to measure the CMJ repeated jumps test described by Bosco. 1,2

Following various studies 4,18 we have considered cities of more than 10 000 inhabitants as urban, and less than 10 000 inhabitants, rural.

The anthropometric assessment was determined by measuring height and body composition. For height, subjects were measured barefoot, standing up, with the heels, buttocks and back in contact with the Anthropometer of Homologated Base GPM (SiberHegner, Ltd, Switzerland) with accuracy of 0.1 cm. The assessment of body composition was carried out via bioelectrical impedance through the impedanciometre TANITA (TBF 300 GS, Arlington Heights, IL, USA).

The first day, as soon as the previously selected subjects arrived, their body composition was measured and analyzed with the instruments previously mentioned, and with this analysis their BMI was calculated, and they were categorized by determining their body weight status (Underweight < 18.5; Normal Weight 18.5–24.9; Overweight 25–29.9 and Obesity >30), using BMI cutoffs according to international standards. 19

For measure the CMJ repeated jumps test, we used the contact platform Tapeswitch Control Mat CKP 30 cm × 48 cm, 24 vac, NEMA 4, BLACK (Anderson-Bolds. Beachwood, OH. USA), with ribbed edge, PC interface module, with a response time less than 25 ms, and a sensitivity to detect subjects whose mass was greater than 25 kg was used to measure the tests of continuous movement jumps. The contact platform software uses the formulas proposed by Bosco 1 to calculate the average flight time, the average contact time, and the average height of J10s and J60s. Moreover, Alactic Power Index (ALACPI) and Lactic Power Index (LACPI), depending on J10s and J60s respectively also are calculated. Finally, the number of jumps whenever there is a contact time is quantified.

The first day of measurement, the CMJ repeated jumps test over 10 s (J10s) took place. The next day, the subjects realized the CMJ repeated jumps test over 60 s (J60s). By doing this, we avoid the accumulation of possible fatigue.

Depending on where the subjects live, the results of this study (Fig. 1) show that the highest rates of overweight and obesity (20.23%) are in rural – Interior subjects, however, they have the lower percentage in underweight body weight status (10.66%).

Fig. 1.

(0.12MB).

Body weight status distribution according to place of participants residence.

However, is the Urban – Interior which has the lower percentage of overweight and obesity. In addition, these subjects have the highest percentage within the underweight status (22.86%). Finally, it can be noted, that this means that they also show the highest percentage of normal weight (67.14%).

In the results of the analysis of variance of a factor, there are no significant differences for the variables measured; average contact time J10s (p = 0.77), number of jumps J10s (p = 0.09), average contact time J60s (p = 0.48), and number of jumps J60s (p = 0.12), finding significant differences for the other variables measured.

After applying Bonferroni's test for multiple comparisons, we found that significant differences are found among the subjects of Urban – Interior and Rural – Interior environments, and between Urban – Coast and Rural – Interior environments; not finding significant differences in the measurements obtained in the test of continuous movement jumps between the subjects of Urban – Interior and Urban – Coast environments (Table 2).

The following graph (Fig. 2) shows the behavior in terms of the average height that subjects reach in J10s and J60s, in both sexes. In males, the normal weight status is that which has the best average height in both tests. However, in women, the behavior is different, as the underweight status is the one that has better performance, subsequently producing a declining relationship, which is attenuated, even equated from overweight status to obesity status.

Fig. 2.

(0.16MB).

Average height of J10s and J60s according to body weight status and sex.

The results of this study suggest that between the values of the variables measured in the repeated jumps test and place of residence, there are significant differences between the subjects of Urban – Interior and Rural – Interior environments, and between the ones of Urban – Coast and Rural – Interior environments. On the other hand, no significant differences were found in the measurements obtained between the subjects of Urban – Interior and Urban – Coast environments. A study with 1501 Spanish adolescent subjects 4 showed significant differences in term of physical condition values among subjects residing in urban and rural environments. However, there was not found in literature any reference that compares the place of Coast residence with any of the other places. This relationship can be explained by the results of our study, which show that there are significant differences among subjects who reside in rural and urban environments; not finding any significant difference in subjects whose place of residence is Coast and Interior. So the difference in terms of physical values measured in school adolescents, would seem to reside purely between urban and rural environments, thus ruling out a possible differentiation with the place of Coast residence. This statement will have to be taken cautiously, because our results only evaluated adolescent's anaerobic parameters. In many studies 6,7,20,21 of school population aged 6–13 years, they have noted that exist significant differences in fitness parameters between subjects of rural and urban areas.

If we analyze the distribution of body weight status by place of residence of the participants the results suggest that the highest percentage of overweight and obesity (20.23%) is found in rural subjects – Interior, however, they have, in turn, the lowest percentage in the status of underweight body weight (10.66%). However, it is in the Urban – Interior environment, which has lower percentage of overweight and obesity. In turn, these subjects are the highest percentage in the underweight status (22.86). Finally, we note what the subjects of this environment is also the highest percentage of normal weight (67.14%). Studies as 20,22,23 have found that the prevalence of overweight and obesity is higher in rural areas than in urban areas. This may be because there is evidence that Spanish children living in rural areas are less physically active than those living in urban areas. 24 To end the BMI analysis, our results suggest that there is a higher prevalence of overweight and obesity (21.43%) in males than in females (13.97%). These results are consistent with the results of a study whose sample was 2320 Spanish adolescents whose results were higher prevalence of overweight + obesity in males (25.69%) than in females (19.13%). 25

The physical condition assessment of school adolescents depending on the place of residence is a field of study which is currently in demand. In the majority of cases, EUROFIT battery is often used for its evaluation. With this battery, the anaerobic performance and differentiating within it between the alactic and lactic variables of the subject in question, is not measured at any moment, so Bosco's CMJ repeated jumps test, could be a good gauge of the anaerobic performance in adolescents, serving as a possible complement alongside the use of the aforementioned battery.

This study showed that there were no significant differences in anaerobic parameters between the places of Coast residence with any other. But if we differentiate urban and rural areas exclusively, we can found significant differences. Therefore, we could assume the possible use of this test as a complement in any test battery to any physical condition assessment.

The authors have no conflicts of interest to declare.