FR3071167A1 - METHOD FOR MONITORING THE SPORTING ACTIVITY OF A USER OF A SELECTIVE LOAD MUSCLE APPARATUS - Google Patents

Abstract

The invention relates to a method for monitoring the sporting activity of a user of a weight-training device with a selectable load, as well as a key device for implementing such a method and a system for the monitoring of the sporting activity of a user of such a device further comprising said key device for the implementation of said method.

Description

METHOD FOR MONITORING THE SPORTS ACTIVITY OF A USER OF A WEIGHT-SENSITIVE APPARATUS WITH SELECTED LOADS

FIELD OF THE INVENTION

The present invention relates to the field of fitness and, more particularly, the field of apparatus present in sports institutes. The invention relates in particular to a method for monitoring the sporting activity of a user of a weight training apparatus with selectable load. It also relates to a key device for implementing such a method as well as a system for monitoring the sports activity of a user of a weight-training apparatus with selectable load, further comprising said key device. for the implementation of said process.

PRIOR ART

The apparatuses present in the fitness centers are mainly divided into three categories: the cardiovascular apparatuses, the machines with selectable loads and the free weights. Although sports halls have met with great success in recent years, the lack of support and monitoring has prompted manufacturers of fitness equipment to develop new technologies around their equipment. These include technologies intended to improve the user experience, for example by offering solutions for better monitoring of sports activity.

The machines with selectable loads are provided with a weight column composed of several plates which move in guided translation along two cylindrical tubes along a vertical axis. The number of plates is selected by means of a metal rod, also called a key device, which passes right through the load through an orifice making it possible to make part or all of the weight stack of the selector . The number of plates selected determines the weight of load moved by the user.

For the identification of the selected load, and, more generally, for the monitoring of the sporting activity of the users of weight training machines with selectable loads, various methods have been developed.

A first method, described in US Pat. No. 6,793,607 B2, consists in equipping each plate of the load column with a presence sensor. The absence of a plate in front of its sensor during movement makes it possible to determine the load selected by the user. This measurement of the load can possibly be coupled to an encoder placed on one of the pulleys of the machine to measure the displacement and thus quantify the number of repetitions of the physical effort produced by the user. Another variant, described in patent application WO 1996029121 A1, consists in placing several sensors on a vertical line of the frame of the machine with selectable charges, and a key emitting a magnetic field is then used for the selection of the charge. weight. The sensors detect the presence of the key emitting a magnetic field and the load is thus determined by the presence of the key when the load is at rest, that is to say when the load weight is not moved. by the user. This variant makes it possible to count the repetitions of the physical effort of the user by following the movement of the key on the vertical axis. However, this technology has several drawbacks. It does not include a communication module or screen or other means to allow feedback to the user relative to his physical effort. Furthermore, it is necessary that the key is connected to an electrical power source. From a practical point of view, the modifications made to the machine with selectable loads are important. The proliferation of sensors increases the risk of system failure. Replacing the sensors is therefore difficult and requires the intervention of a highly qualified technician.

described in the technical distance, the movement within

A second method consists in measuring a fixed point. This allows to follow determine its position means implemented determine the position ultrasound, laser, electromagnetic. This several disadvantages and US Patent 6494811 B1, between the key and one based on telemetry, the key and the weight stack. The follow the movement and the key are multiple: infrared, radiation method nevertheless presents in particular the absence of communication module and the need to be connected to a power outlet, or possibly integrate a battery that the staff of the sports center will have to recharge periodically. In this system, precise calibration for each fitness machine is necessary to determine the relationship between the selected load and the distance to the fixed point. In addition, a risk of obstruction of the distance sensor may also appear over time. This constraint has prompted manufacturers to integrate a blower into the device in order to expel dust that can accumulate in the reflection mechanism over time. In addition, if the transmitter is present within the key, its insertion in the weight stack must be standardized in order to respect the alignment between the receiver and the reflector.

Furthermore, patent WO 2015/113162 A1 describes a device consisting in equipping the weight bars with a sensor at one of its ends. The sensor is capable of recognizing the value of the charge added or removed by means of read information which is carried by the charge and which may be a barcode, NFC (Near Field Communication) technology. or BLE (Bluetooth ™ Low Energy; Bluetooth ™ low energy) or even a color code. This technology works by wireless communication and is not present in a key. The association between the weight training machine with selectable loads and the user is allowed via a tag (RFID, QR code (Quick Response code; quick response code), barcode, color code) associating a connected bracelet, belonging to the user, with the machine. These methods increase the constraints linked to the pairing between the different devices and the user-based pairing. In regards to

QR code, barcode or color code, a fine alignment between the code and the reader must be respected, in particular in the case of a small device with a reader close to the

This alignment is necessarily carried out manually by the user in the solutions proposed in the state of the art. This poses a concrete problem of robustness and simplicity of implementation of such a method of monitoring sports activity with a risk of weariness in the face of the complexity of the operations to be performed during each change of machine. In the case of radio identification, the power supply of the device poses a problem, because NFC or RFID technologies consume energy, which is not compatible with long-term nomadic operation. The use of an external power supply is then necessary, except to impose at regular intervals a recharge of the batteries of the system, which also poses a problem in terms of simplicity of use.

SUMMARY OF THE INVENTION

In view of the above, the invention proposes to carry out a new method for monitoring sports activity which overcomes the aforementioned drawbacks of the prior art and which, in particular, has good robustness and great simplicity in its use.

In a first object, the invention relates to a method for monitoring the sports activity of a user of a weight training apparatus with selectable load, according to which:

there is provided a selectable load weight training apparatus comprising a plurality of load weights, each load weight being provided, on the one hand, with an opening for selecting the load and, on the other hand, with a label identification affixed to said weight;

a key device is provided for selecting a load weight, said key device comprising a metal rod provided, at one of its ends, with a housing comprising a connected electronic control unit comprising at least one reading device identification labels affixed to the load weights, a means of communication with an external activity monitoring device and a means of supplying energy to said power station;

for the selection of the load, the metal rod of the key device is inserted into an orifice of a load weight of the weight training machine;

for reading the identification label affixed to the weight of the selected load, the reading device, contained in the key device inserted in the load weight, is readjusted without user intervention;

the identification label affixed to the weight of the selected load is read by means of the reading device of the electronic control unit of the key device; and the information read is communicated to the external activity monitoring system.

In a second object, the invention relates to a key device for implementing the method as described above, characterized in that it comprises:

a metal load weight selection rod, said rod being provided, at one of its ends, with a housing;

a connected electronic central unit, said central unit being contained in said housing and comprising at least one device for reading a label affixed to a load weight of said weight training machine, at least one movement sensor of the key device, at least one means communication and at least one means for supplying said electronic central unit; and means for autonomous registration of said reading device with said label affixed to the weight of the selected load of the weight training machine.

In a third subject, the invention relates to a system for monitoring the sporting activity of a user of a weight-training machine with selectable load comprising a weight-training machine with selectable load, a smartphone, and a key device for the implementation of the method as described above.

Advantageously: - the electronic central unit (31) further comprises a movement sensor, and in that the information communicated to the external activity monitoring device includes information relating to the movements of the key device inserted in a weight of load (14) for monitoring the series carried out by the user of the weight-training apparatus with selectable load (10); - the label affixed to the load weight (14) of said weight training machine (10) is a color label, an RFID label, a QR code and / or a bar code and in that the reading device of the the label affixed to the load weight is a color sensor, an RFID label reader, a QR code reader and / or a barcode reader, respectively; - The label affixed to the load weight (14) of said weight training machine (10) is a color label and in that the label sensor is a color sensor; - the key device comprises a counterweight positioned eccentric with respect to the axis formed by the metallic selection rod (23) of said key device (15), the weight of said counterweight being sufficient to cause rotation of the electronic control unit ( 31) when the metal rod (23) is inserted into the orifice (16) of a weight (14) of the weight-training apparatus with selectable load (10), for the resetting of the device

reading contained in the key device (15) without user intervention, and reading the label; - the key device (15) is connected to elastic resetting means causing a rotation of the electronic control unit (31) when the metal rod (23) inserted in the selection orifice (16) of a weight (14) of the weight training apparatus with selectable load (10), for the readjustment of the reading device contained in the key device (15) without the intervention of the user, and the reading of the label; - the electronic central unit (31) comprises means for determining the orientation of the reading device, and in that, for the readjustment of said reading device, the orientation of the sensors and / or code readers is determined by means of said means determining orientation; - n labels are affixed to the load weight (14) of said weight training device (10), and in that the reading device comprises at least n + 1 sensors and / or code readers; - the housing (24) comprising the connected electronic central unit (31) is provided with at least one magnet, preferably at least two magnets; - The smartphone (21) supplies the key device (15) with energy by wired or non-wired means.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be better understood on reading the following nonlimiting description, drawn up with reference to the appended drawings, in which:

- Figure 1 shows a weight training device with selectable load provided with a key device according to the invention;

- Figure 2 is a representative diagram of a key device according to the invention;

- Figures 3A and 3B are two sectional views of a housing of a key device according to a first and a second embodiment according to the invention;

Figures 4A and colors affixed with

4B show labels concentrically around the orifice of a weight of the column of loads selectable according to two different embodiments;

Figures 5A and

5B are two sectional views of a key device housing, FIG. 5A represents the housing of the key device introduced into a selectable load weight of the weight training apparatus before a resetting step according to the method of the invention , and FIG. 5B represents the said housing after a registration step according to the method of the invention; and the figure represents two color labels affixed concentrically around the orifice of a weight of the column of selectable loads, and FIGS. 6B and 6C represent a sectional view of the electronic control unit comprising three color sensors in two different positions.

DESCRIPTION

DETAILED OF THE INVENTION

Gyms are now equipped with a multitude of sports machines including cardiovascular machines, weight training machines with selectable load, and free weights. In order to improve the user experience in monitoring his sporting activity, the invention proposes, in this context, a new method for monitoring the sporting activity of a user of a weight training apparatus with selectable load. The implementation of this process makes it possible in particular to carry out a constant, reliable and optimized monitoring of the sporting activity of a user over time. In addition, the implementation of this process is robust and reproducible from one weight training machine to another. In other words, such a method is adaptable to any weight training machine with selectable load column and does not require complex intervention by the user.

In this context and according to a first object, the invention relates to a method for monitoring the sports activity of a user of a weight training machine with selectable load. This method comprises a first step according to which a weight training machine with selectable load is provided.

a plurality of weights

The weight training apparatus comprises a load, each load weight being provided, on the one hand, with an orifice for selecting the load and, on the other hand, with an identification label affixed to said weight.

More specifically, and as it appears from the

1, the weight training apparatus 10 comprises a built figure comprising a horizontal base 11 placed on the ground, on which a vertical structure is mounted, and the vertical structure is itself surmounted by a horizontal support

19. The vertical structure comprises two parallel external vertical plates 12 ensuring the stabilization of the weight training machine, and two parallel cylindrical vertical bars 13 ensuring the maintenance and cohesion of the weights of the weight training machine along a vertical axis. The weight training apparatus also comprises a column of weights with selectable loads 14. The weights of the column of weights 14 are movable in vertical translation along the bars 13.

According to another step of the method, a key device is provided for the selection of a load weight in the weight column. This key device is referenced 15 in FIG. 1. It is detachably inserted into a weight of the weight column with selectable load 14, through an orifice 16 of said weight. A supply means 17 connects the key device 15 to the frame of the bodybuilding apparatus, by means of extendable fasteners 18. Said extendable fasteners are for example springs or elastic positioned on the vertical exterior structure 12 of the frame of the weight training machine. In a particular embodiment, the key device 15, as shown in FIG. 2, comprises a metal rod 23 provided, at one of its ends, with a gripping case 24 comprising a connected electronic central unit. More particularly, the metal rod 23 is substantially rectilinear, and has, in one example, a length of

Its section is circular, with a diameter generally between 8 and 10 mm, but may also have another shape, such as for example a rectangular shape. In one embodiment, the gripping unit comprising the connected electronic central unit 31 is provided with at least one magnet, preferably at least two magnets. These magnets are, more particularly, of cylindrical shape and arranged on the housing at equal distance on either side of the metal rod for selecting the load weight.

It is understood that a person skilled in the art can adapt the shape and the position of these magnets according to the desired practicality. As described in FIGS. 3A and 3B, the gripping unit 24 comprises an electronic central unit 31. The electronic central unit 31 comprises at least one device for reading the identification labels affixed to the load weights of the weight training machine, a means of communication with an external activity monitoring device and a means of supplying energy to said power station.

The means of communication with the external monitoring device make it possible to collect, on the one hand, information relating to the monitoring of the sporting activity of the user of the weight training apparatus and, on the other hand, statistics of use to define the wear of the weight system. This external device notably includes a screen. It is for example a smartphone or a tablet.

The electronic central unit also includes a means of supplying energy. More particularly, and as shown in FIGS. 3A and 3B, the electronic control unit is surmounted by a female USB port 33 making it possible to receive a wired power supply means 17 via a male USB port 34 mounted on the wired power cable 17.

In a preferred embodiment and shown in FIG. 2, the cable 17, allowing the energy supply to the connected electronic central unit, is associated with an energy source or with a support capable of receiving an energy source. This energy source is preferably formed by a smartphone 21. In one embodiment, this smartphone 21 is connected to the cable 17 directly by a wired connection. The wired connection being intended in particular to provide energy, the various forms known in the state of the art can be used: Jack, USB of different types. For example, a wired connection can be envisaged between a port of the male JACK type carried by the cable 17 and a port of the female JACK type carried by the smartphone 21. In another embodiment, the smartphone 21 provides energy indirectly by means of a wireless connection 22. In a particular embodiment, the wireless connection is a near field connection of the NFC type. In practice, the smartphone 21 belongs to the user of the weight-training apparatus with selectable load. The cable 17 thus allows the supply of said device 15 with energy.

Before starting his sporting activity, the user therefore associates his smartphone 21 with the key device either directly or indirectly as described above.

Of course, those skilled in the art are able to adapt the types of connections, whether wired or non-wired, depending on the practicality sought.

Furthermore, the supply means coupled to a specific form of the gripping housing 24 makes it possible to define an anti-theft system of the key device.

According to a first variant of the invention, and as shown in the figure

3A, the box 24 has a particular shape by the presence of notches 35 which prevent the separation of the USB link and 34 and make it possible to ensure the anti-theft function of the key device 15.

According to a second variant of the invention, and as shown in FIG. 3B, the box 24 is surmounted by two additional plates 36 fixed to the box 24 by a screw-type fixing means 32, which prevent the two ports from being separated. USB 33 and 34 and provide the anti-theft function of the key device 15.

In a preferred embodiment, the device for reading the identification labels affixed to the load weights further comprises a motion sensor and an orientation sensor. In another embodiment, the motion sensor also performs the function of the orientation sensor. In other words, the motion sensor can also be an orientation sensor. The motion and / or orientation sensor can be an accelerometer, a gyroscope and / or a magnetometer. The movement and / or orientation sensor makes it possible to identify the position of the key device when it is at rest and when it is in motion. By “key device at rest”, it is understood that the metal rod of the key device is inserted into a weight of selectable loads, but that the user does not achieve any increase in the weight of the column of selected loads. By "key device in motion", it is understood that the metal rod of the key device is inserted into a weight of the column of selectable loads, and that the user performs an elevation of said column.

The motion sensor in particular allows information to be sent back to the user's smartphone. The reading device makes it possible to communicate information to an external device for monitoring sports activity.

The information communicated is relative, in particular the physical effort made.

This information also includes information relating to the movements of the key device inserted in a load weight for monitoring the series carried out by the user of the weight training apparatus with selectable load. Furthermore, the device for reading a label affixed to a load weight of said weight training machine provides the return of information concerning the type of weight training machine with selectable loads used and the load weight selected. By "type of weight training machine with selectable load" is meant machines which involve different categories of muscles or groups of muscles for the work of one or more parts of the body at the same time. For example, it can be a machine of the chest press type, also called "Chest press" in English. This particular type of device allows the strengthening of the pectorals, deltoids and triceps simultaneously.

In one embodiment, the device for reading the label affixed to the load weight comprises a color sensor, an RFID label reader, a QR code reader and / or a barcode reader, respectively. The label (s) allowing information to be returned to the user are, in the context of the invention, affixed to each load weight of the weight training machine. In one embodiment, the label affixed to the load weight is a color label, an RFID label, a QR code and / or a bar code and the device for reading the label affixed to the load weight is a color sensor, RFID tag reader, QR code reader and / or barcode reader, respectively. The sensor (s) are arranged in the electronic control unit so that, when the key device 15 is inserted into the orifice 16 of the weight of the column of selectable loads, the color sensor (s) are readjusted so as to be superimposed the label affixed to the weight of the weight system.

In an alternative embodiment, the color label is a single label composed of a single color or a plurality of colors. As shown in FIGS. 4A and 4B, at least two labels 41 are, for example, affixed to each of the load weights of the weight training machine. The label or labels are arranged around each of the orifices 16 of each of the weights of the weight-training apparatus with selectable load receiving the metal rod 23 of the key device 15. The labels thus each have a concentric shape of the semicircle type or quarter circle. Of course, a person skilled in the art is able to adapt the shape and the position of each of the labels affixed to the weight of the weight training machine with selectable loads, depending on the practicality sought.

In another embodiment, a color label can be defined by these levels of red, green and blue (RGB) or a code in another color space, such as for example defined by its levels of cyan, magenta , yellow, black (CMYK or in English-language CMYK). Thus, in the context of the invention, information can be associated with each of the RGB levels of a label. For example, a single label can communicate up to three pieces of information. This last embodiment makes it possible not to be limited in the number of information read and by the colors of the different labels affixed.

According to another step of the method, for the selection of the load, the metal rod of the key device is inserted into an orifice with a load weight of the weight training machine. This operation is the one and only step requiring the intervention of the user of the weight training apparatus for the implementation of the method according to the invention.

According to another step of the method, for reading the identification label affixed to the weight of the selected load, the reading device, contained in the key device inserted in the load weight, is readjusted independently, without user intervention. According to one embodiment, if n labels are affixed to the load weight of said weight training device, then the reading device comprises at least n sensors and / or code readers. The label affixed to the load weight of said weight training machine can more particularly be a color label and the label sensor can be a color sensor, n being an integer greater than or equal to 1, preferably greater than or equal to 2, and in an example equal to 2 or 3.

In a first alternative embodiment, the key device comprises a counterweight positioned eccentric with respect to the axis formed by the metal rod for selecting said key device, the weight of said counterweight being sufficient to cause rotation of the electronic control unit when the metal rod is inserted into the orifice of a weight of the weight training machine with selectable load, for the readjustment of the reading device contained in the key device without

User intervention, and for reading the label.

In other words, the center of gravity of the counterweight must not be located on the axis of rotation of the electronic control unit. By "sufficient", it should therefore be understood that the counterweight allows the adequate rotation of the electronic control unit without implying too great a weight of the key device. For example, the weight of the counterweight is between 20 and 400 grams, the limits of this interval being included.

In a second variant embodiment, the key device is connected to means of extendable retraining fasteners causing a rotation of the electronic unit when the metal rod inserted in the weight selection orifice of the weight training apparatus with selectable load, for readjustment of the reading device contained in the key device without user intervention, and for reading of the label. As described in the figures

5A and

5B, the power cable connects the key device 15 to the frame of the weight training apparatus by means of extendable fasteners

52. Said means of extendable fasteners are for example springs or elastic positioned on the horizontal structure of the frame of the weight training machine. In FIG. 5A, user of a weight training machine with selectable load has just introduced the key device 15 into a weight of the load column.

The power cable undergoes a return force 51 due to the presence of the means of extendable fasteners 52. The return force 51 then generates a rotation of the electronic control unit around

The axis of the metal rod 23. In the figure

5B, the electronic control unit comprising the device for reading the labels affixed to the selectable load weight is readjusted.

In these sensors, the last two variants of labels are found in relation to the n labels affixed on completion, the n thus readjusted by the load weight of the weight training device, allowing optimal return of the information affixed to the device.

This rotation thus allows no adjustment operation of one of the communication communication and labels outside.

it is up to the user to ensure that the label reading device contained in the electronic control unit is perfectly aligned with the labels affixed to a load weight of

The weight training machine.

In another mode, that is to say without are affixed to bodybuilding, then minus n + 1 embodiment known as mechanical registration, if the algorithmic sensors, load weight of said reading device and / or device label readers includes codes .

from to

In particular, the electronic central unit further comprises means for determining the orientation of the reading device. To readjust the orientation of the sensors determined by said orientation.

the relative orientation of

These said and / or average means allow n + 1 sensors compared to the n labels.

reading device, determination code reader is to determine position and / or code reader

As has been described above, the means for determining the orientation are more particularly a motion sensor and / or an orientation sensor. In a preferred embodiment, one and the same sensor fulfills the function of both the motion sensor and that of the orientation sensor, such as for example an accelerometer. A magnetometer and / or a gyroscope can also be used in other alternative embodiments.

In a particular embodiment, and as described in FIGS. 6A, 6B and 6C, two colored labels 61 and 62 of concentric shapes are affixed around the orifice 16 of the load weight of the weight training machine. The connected electronic central unit 31 contained in the gripping unit of the key device comprises three color sensors 63A, 63B and 63C equidistant from each other. Two possible orientations of the color sensors are described in FIGS. 6B and 6C. As described in FIG. 6B superimposed on FIG. 6A, the color sensor 63A is positioned both on the label 61 and on the label 62 and does not, in this case, refer back to 'information read to an external communication device. On the other hand, the sensors 63B and 63C are positioned opposite the label 61 and 62, respectively. As described in FIG. 6C superimposed on FIG. 6A, the color sensor 63A is positioned opposite the label 61, and the sensors 63B and 63C are positioned opposite the label 62. In these last two cases of overlapping, a movement and / or orientation sensor (not shown in FIGS. 6B and 6C) makes it possible to identify the orientation of the sensors 63B and 63C relative to the labels 61 and 62, and an optimal reading information from the labels affixed is produced by the n + 1 sensors to ensure good monitoring of sporting activity.

Thus, the registration step according to the method of the invention, whether mechanical or algorithmic, makes it possible to make the device for reading the labels affixed to a load weight of the weight training device robust and easy to use. . Indeed, the user of the weight training machine with selectable loads will not need to make a particular effort to adjust the label reading device contained in the electronic control unit with the labels affixed to a load weight of the musculation tool. In other words, the key device 15 once supplied with energy and introduced into the orifice 16 of the selectable load column is autonomous and does not require any intervention by the user to read the labels affixed on the weight of the weight system.

According to another step of the process, the identification label affixed to the weight of the selected load is read by means of the reading device of the electronic unit of the key device.

According to a last step of the process, the information read is communicated to the external device for monitoring sports activity.

The information is of the type described above.

The method of monitoring sports activity according to the invention therefore has good robustness and great simplicity in its use. The key device 15 is autonomous in reading the labels affixed to the weight of the selectable load column. In particular, no user intervention is necessary to read the labels affixed to the weight of the weight training machine correctly. Such a device therefore confers a significant saving of time for the user of the weight training device since the latter no longer needs to carry out a specific pairing between the smartphone and the weight training device as was necessary in the devices. of the prior art.

In a second object, the invention relates to a key device for implementing the method as described above. This key device includes:

a metal load weight selection rod, said rod being provided, at one of its ends, with a housing;

a connected electronic central unit, said central unit being contained in said case and comprising at least one device for reading a label affixed to a load weight of said weight training apparatus, at least one movement sensor of the key device, at least one means communication and at least one means for supplying said electronic central unit; and means for autonomous registration of said reading device with said label affixed to the weight of the selected load of the weight training machine.

In a third object, the invention relates to a system for monitoring the sports activity of a user of a weight-training apparatus with selectable load. This system comprises a weight-training apparatus with selectable load, a smartphone, and a key device for implementing the method as described above. In particular, the smartphone supplies the key device with energy by wired or non-wired means. In a particular embodiment, the system according to the invention is connected to a server. The server belongs to the sports hall and allows the collection of information relating to the use of the weight training apparatus with selectable load, such as for example data relating to the physical effort made by the user of said apparatus. . The collection of these data also allows better monitoring of the wear of the load-bearing resistance training machine, selectable by the manager of the sports hall.

Claims (10)

1. Method for monitoring the sporting activity of a user of a weight training apparatus with selectable load, according to which: there is provided a selectable load weight training apparatus (10) comprising a plurality of load weights (14), each load weight (14) being provided, on the one hand, with an orifice (16) for the selection of the load and, on the other hand, an identification label affixed to said weight (14); a key device (15) is provided for selecting a load weight, said key device comprising a metal rod (23) provided, One of its ends, of a box (24) comprising a connected electronic central unit (31) comprising at least one device for reading identification labels affixed on the weight charging (14), a way of communication with an external device of followed of Activity and a way supply in energy of said power plant; for the selection of the load, the metal rod (23) of the key device (15) is inserted into an orifice (16) of a load weight (14) of the weight training machine (10); for reading the identification label affixed to the weight of the selected load (14), the reading device, contained in the key device (15) inserted in the load weight (14), is readjusted without intervention of the user; the identification label affixed to the weight of the selected load (14) is read by means of the reading device of the electronic control unit (31) of the key device (15); and the information read is communicated to the external activity monitoring system. 2. Method according to claim 1, characterized in that the electronic central unit (31) further comprises a movement sensor, and in that the information communicated to the external activity monitoring device includes information relating to the movements of the device key inserted in a load weight (14) for monitoring the series performed by the user of the weight training apparatus with selectable load (10). 3. Method according to one of the preceding claims, characterized in that the label affixed to the load weight (14) of said weight training device (10) is a color label, an RFID label, a QR code and / or a bar code and in that the device for reading the label affixed to the load weight is a color sensor, an RFID label reader, a QR code reader and / or a bar code reader, respectively. 4. Method according to claim 3, characterized in that the label affixed to the load weight (14) of said weight training machine (10) is a label of color sensor and in this of color. that the label sensor is a 5. Process according to 1 'a demands previous, caract erected in this the device wedge comprises a counterweight positioned eccentrically to the axis formed by the metallic selection rod (23) of said key device (15), the weight of said counterweight being sufficient to cause rotation of the electronic control unit (31) when the rod metal (23) is inserted into the orifice (16) of a weight (14) of the weight-training apparatus with selectable load (10), for the registration of the reading device contained in the key device (15) without user intervention, and reading the label. 6. Method according to one of claims 1 to 4, characterized in that the key device (15) is connected to elastic resetting means causing a rotation of the electronic control unit (31) when the metal rod (23) inserted in the selection hole (16) of a weight (14) of the device of bodybuilding at load selectable (10), for the retiming of reading device contained in the device of key (15) without user intervention, and reading of the label. 7. Method according to one of claims 1 to 4, characterized in that the electronic central unit (31) comprises means for determining the orientation of the reading device, and in that, for the readjustment of said reading device, the orientation of the sensors and / or code readers is determined by means of said orientation determination means. 8. Method according to claim 7, characterized in that n labels are affixed to the load weight (14) of said weight training device (10), and in that the reading device comprises at least n + 1 sensors and / or code readers. 9. Method according to one of the preceding claims, characterized in that the housing (24) comprising the connected electronic central unit (31) is provided with at least one magnet, preferably at least two magnets. 10. Key device for implementing the method according to one of claims 1 to 9, characterized in that it comprises: a metal rod (23) for selecting the load weight (14), said rod (23) being provided, at one of its ends, with a housing (24); a connected electronic central unit (31), said central unit (31) being contained in said housing (24) and comprising at least one device for reading a label affixed to a load weight (14) of said weight training machine (10), at least one movement sensor of the key device (15), at least one communication means and at least one means for supplying said electronic central unit (31); and means for autonomous registration of said reading device with said label affixed to the weight of the selected load (14) of the weight training machine (10). 11. System for monitoring the sporting activity of a user of a weight training machine with selectable load, comprising a weight training machine with load selectable (10), a smartphone (21), and a key device (15) for placing implemented of method according to one of claim 1 to 9. 12. System according to claim 11, characterized in that the smartphone (21) powers the wired key device.