# Noise Source Identification in Training Facilities and Gyms
## 1 Introduction  
The noise, vibrations, and impacts issue in so-called sport and fitness centers is an actual and growing problem. The development of industrialization and globalization has moved a significantly large part of the population to cities. The natural environment for the human body to stay in good physical condition has thus been moved from the physically demanding (relatively) country sides to the comfortable and easy good-access city environment. To counteract the situation of a drop in human body fitness and wellness, the fitness centers business is a developing and growing business branch [1]. Consequently, sport centers in the cities have started to cover a large amount of space. The perfect location for such a place, from the business point of view, is buildings in close vicinity of offices and residential areas. Another factor is the great rise in the popularity of cross training and functional training fitness centers, where weights are not used in a so-called \"quasi-static\" way (like in a classic gym). Dynamic ballistic lifts of free weights, box jumps, or slams are commonly performed [1]. Research has proved that heavy concrete floors are characterized by the best performance in the low frequencies but in a wide range of frequencies, damped lightweight floors give the best overall performance [2, 3]. In the worst cases, where no proper bumpers and structure protections are adapted, destruction of the load-bearing structure can be observed (Figure 1). This gives a clear picture that the proximity of the heavy weights dropping around offices and residential buildings increases technical and environmental conflict. When \"exercise-borne noise\" is additionally combined with excessively loud music, which is common in sport centers, this may even result in hearing damage [4]. [PERSON] and [PERSON] [5] reported peak noise levels between 90.5 and 99.7 dB(A) and the overall mean noise level of aerobics classes was 87.1 dB(A), indicating that the music during exercise was the main source of noise. Another study of the noise level during aerobics classes, carried out by [PERSON] [6], found a mean noise level at 89.6 dB(A). [PERSON] and [PERSON] [4] reported average levels of over 93.1 dB(A) during high-intensity fitness activity. [PERSON] and [PERSON] [7] indicated that noise levels during aerobic classes often exceeded the levelsrecommended for occupational noise exposure, with average noise levels ranging from 78 to 106 dB(A). [PERSON] et al. [8] found that about 20-25% of physical education teachers could achieve a weekly noise exposure higher than 80 dB(A) induced by sport activity and schools. [PERSON] and [PERSON] [9] registered sound levels during warm-up without equipment of 50 to 80 dB(A), exercises with balls of 55 to 90 dB(A), team matches of 77 to 93 dB(A), and other activities of 70 to 90 dB(A). More recently, [PERSON] [10] reported the average noise exposure for sports instructors of 92.6 dB(A), and most of the measurement values were above the occupational exposure limit of 85.0 dB(A). Although the research presented above does present data regarding noise levels during fitness activities, it is not clear how to differentiate between noise caused by music and movement patterns performed by participants. Loud music during exercise can be easily reduced while noise caused by dynamic lifts, box jumps, or slams has not yet been identified nor is it easy to reduce. The localization of sources, acoustics, and vibration isolation in fitness centers should be investigated in three parallel directions: first, structure-borne noise and vibration and its transfer to the surrounding buildings; and second, noise analysis according to common rules and standards to allow legal operation of the sport centers [11,12]. This point proves to be complicated in many countries and regions due to the lack specific standards and test procedures for fitness centers [13].