PhD, Associate Professor A.B. Petrov¹
Dr. Biol., Professor A.N. Vyotosh¹
PhD, Associate Professor G.M. Lavrukhina¹
A.S. Kotova^1
1Lesgaft National State University of Physical Education, Sport and Health, St. Petersburg

Corresponding author: sport_med@list.ru

Abstract

Objective of the study was to test by experiment the application of the acoustic activity recording devices during sleep to assess the processes of recovery after physical loads.

Methods and structure of the study. The experiment involved the 19-20 year-old males (n=36) specializing in cyclic sports with three trainings in a weekly microcycle: average body mass - 74.6 kg, height - 176.5 cm, heart rate at rest - 62 bpm, blood pressure at rest - 120/80 mmHg.

The subjects’ somnological parameters were recorded using the SleepCycle 5.5.3 application, which allows for contactless and non-invasive registration of the flow of acoustic accompaniment of physiological activity during daily sleep. The application was developed by the research group Northcube AB (Gothenburg, Sweden) led by Maciek Drejak.

The intensity and duration of physical loads were recorded based on the athletes’ notes in the diaries.

Two series of studies were conducted. In the first study series, 24 subjects were tested for 7 days against the background of their routine, daily physical activity under the academic training program.

In the second study series, 12 subjects were tested for 14 days to estimate their acoustic activity during sleep: the first 7 days - against the background of their routine, daily physical activity, the next 7 days - after a dosed physical load in the afternoon.

The processing of the recording of the individual acoustic activity during sleep made it possible to calculate the duration of night sleep, the duration of each cycle and its average value, the time to fall asleep, the depth of sleep, the total time of deep and shallow sleep, the quality of sleep.

Results and conclusion. The data obtained are consistent with the studies conducted by A.M. Vein’s group (1991) with the application of the method of polysomnographic recording during aerobic activity The applied hardware, not related to classic polysomnography, method of recording sleep parameters makes it possible to obtain a wide range of data and study the effects of physical activity on the human body. This approach can probably be used in further detailed elaboration as a method of control and assessment of the effectiveness of the training process.

Keywords: somnogram, aerobic activity, acoustic activity of the human body during sleep.

Background. Physical loads activate the physiological, biochemical, and psychological reserves of the body. At the same time, long-term physical activity depletes these reserves, which cannot but affect the structure and quality of subsequent recovery processes [6, 7, 9]. Sleep is an essential part of athletes’ recovery. Numerous attempts were made to study the relationship between the specific features of physical training and their manifestations during sleep [2-4]. The introduction of polysomnography in the methodological arsenal of scientists has set these studies on the scientific ground [4, 5]. However, the organizational and hardware complexity of the polysomnographic approach did not allow sports somnology to develop properly [8].

In recent years, significant progress in computational and communication electronics has led to the emergence of promising mobile applications for sports somnology at free and resource-light access. These applications help more and more effectively monitor the state of the body under loads and during recovery, including at night [12]. In this view, there is a new opportunity to apply polysomnography in the assessment of load efficiency, which, in turn, will make it possible to update training design and control.

Objective of the study was to test by experiment the application of the acoustic activity recording devices during sleep to assess the post-exercise recovery processes.

Methods and structure of the study. The experiment involved the 19-20 year-old males (n=36) specializing in cyclic sports with three trainings in a weekly microcycle: average body mass - 74.6 kg, height - 176.5 cm, heart rate (HR) at rest - 62 bpm, blood pressure (BP) at rest - 120/80 mmHg.

The subjects’ somnological parameters were recorded using the SleepCycle 5.5.3 application, which allows for contactless and non-invasive registration of the flow of acoustic accompaniment of physiological activity during daily sleep. The application was developed by the research group Northcube AB (Gothenburg, Sweden) led by Maciek Drejak [11].

The intensity and duration of physical loads were recorded based on the athletes’ notes in the diaries.

Two series of studies were conducted. In the first study series, 24 subjects were tested for 7 days against the background of their routine, daily physical activity under the academic training program.

In the second study series, 12 subjects were tested for 14 days to estimate their acoustic activity during sleep: the first 7 days - against the background of their routine, daily physical activity, the next 7 days - after a dosed physical load in the afternoon (continuous swimming at a moderate rate, at HR of 120-150 bpm, 30 minutes).

Subjects’ acoustic activity during sleep: 1 – wakeful state; 2 – shallow sleep; 3 – sleep; 4 – deep sleep; А – time to fall asleep; B – total sleep duration.

The processing of the recording of the individual acoustic activity during sleep made it possible to calculate the duration of night sleep, the duration of each cycle and its average value, the time to fall asleep, the depth of sleep, the total time of deep and shallow sleep, the quality of sleep (see Figure 1).

Results and discussion. Given in Table 1 are the data on the processing of the individual somnograms in EG1 registered by SleepCycle.

The proper values of the calculated parameters were obtained by means of polysomnography in application to young males and taken from various literary sources [1, 2, 3, 5, 10]. The comparison of the data obtained indicated a reliable degree of matching of the somnographic data obtained by different methods.

Table 1. Acoustic data (М±σ) in EG 1 and their proper (P) values

Given in Table 2 are the quantitative values of the somnographic data obtained in EG2 before and after physical loads.

The comparative analysis of the acoustic data obtained before and after physical loads revealed that moderate aerobic activity significantly reduces the time to fall asleep, increases the duration of sleep in an ad libitum mode (as one pleases), as well as improves the quality of sleep, according to the SleepCycle app. At the same time, aerobic exercise affected the structure of sleep. Thus, the total duration of deep sleep significantly increased, while the duration of shallow sleep significantly decreased.

Table 2. Somnological parameters before (B) and after (A) physical loads

The data obtained are consistent with the studies conducted by A.M. Vein’s group (1991) with the application of the method of polysomnographic recording during aerobic activity [3].

Conclusion. The applied hardware, not related to classic polysomnography, method of recording sleep parameters enables to obtain a wide range of data and study the effects of physical activity on the human body. This approach can probably be used in further detailed elaboration as a method of control and assessment of the effectiveness of the training process.

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