Pulse rate estimation method, training method, exercise instruction device, and pulse rate estimation system

Abstract

The present invention addresses the problem of providing: a method and a system for estimating pulse rate in ST or ST2 in which an exercise time is shorter than a conventional Ramp load; a training method for performing exercise using, as an index, the pulse rate estimated using the estimation method; and an exercise instruction device and an exercise instruction system capable of issuing an instruction pertaining to exercise intensity using, as an index, the pulse rate in ST or ST2 of an individual. There are provided, as a solution: a pulse rate estimation method in which, while a subject is imparted with a fixed load at which the pulse rate is 75-90% of the maximum heart rate for 2-10 minutes, there is determined either a decrease start point at which the measured value of SpO2 starts to exhibit a tendency to decrease or an inflection point at which the behavior of a value (SpO2 / pulse rate) obtained by dividing the blood oxygen concentration by the pulse rate changes, and the pulse rate in ST or ST2 is estimated on the basis of the determined point; an estimation system with which it is possible to realize the aforementioned estimation method; and a training method and an exercise instruction device in which the aforementioned estimation method is used.

Description

Pulse rate estimation method, training method, exercise instruction device, and pulse rate estimation system

[0001] The present invention relates to a pulse rate estimation method, a training method, an exercise instruction device, and a pulse rate estimation system.

[0002] Many reports have shown that the higher one's physical fitness, such as muscle strength and cardiopulmonary capacity, the higher one's health and survival rate, and the lower the mortality rate (Non-Patent Document 1). To improve one's physical fitness, such as muscle strength and cardiopulmonary capacity, one must exercise at a moderate intensity or higher; for example, continuing to exercise at an insufficient intensity will not improve one's physical fitness. While the level of moderate-intensity exercise differs for each individual, it is known that the anaerobic threshold (AT) is a moderate-intensity exercise for all people. The term "anaerobic threshold" refers to the intensity at which, as the intensity of exercise increases, the supply of oxygen required for muscle energy consumption can no longer keep up, and blood lactate begins to increase rapidly (see, for example, the Ministry of Health, Labor and Welfare website, e-Health Net).

[0003] Furthermore, as a standard for exercise intensity more intense than the AT, there is the respiratory compensation start point (RCP), which is the upper limit of exercise intensity that can be sustained before metabolic acidosis causes severe hyperventilation. Exercise intensities above the AT further increase the rate of increase in blood carbon dioxide, but further increases in exercise intensity also lead to a corresponding increase in blood carbon dioxide concentration. The RCP is the point at which the increased blood carbon dioxide levels associated with increased exercise intensity begin to be actively expelled by increasing the respiratory rate. It is known that athletes and others seeking extremely high levels of athletic performance can efficiently improve their physical abilities by exercising within the AT-RCP range, with the RCP as the upper limit, and at an intensity of approximately 80-95% of the RCP exercise intensity.

[0004] To measure AT and RCP, a cardiopulmonary exercise stress test is required. A cardiopulmonary exercise stress test involves measuring oxygen intake and carbon dioxide output using an exhaled breath analyzer while applying gradually increasing exercise loads (ramp loads) (see Non-Patent Document 2, p. 22, "3. Cardiopulmonary Exercise Stress Test"). Conventionally, to measure AT and RCP, a subject must exercise to the point of immobility while breathing through a mouthpiece connected to an exhaled gas measuring device under the supervision and guidance of a trainer. This requires special equipment, and therefore could only be performed in hospitals, sports universities, research institutes, etc. The present applicant has conducted a cardiopulmonary exercise stress test using blood oxygen concentration (SpO ２ The applicant has proposed a method for estimating the optimal exercise intensity corresponding to AT (Patent Document 1) and a method for estimating the upper exercise intensity corresponding to RCP (Patent Document 2) from the measured values ​​of SpO ２ The trademarks used for exercise intensity estimated by the measured values ​​are "oxygen saturation threshold" and "SpO ２ The company has obtained registered trademarks under the trademark "Threshold" (Japanese Trademark Registration Nos. 6782033 and 6782034). Hereinafter, the optimal exercise intensity will also be referred to as "ST" and the upper limit exercise intensity will also be referred to as "ST2." All documents, patent applications, and technical standards described in this specification are incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

[0005] Patent No. 6990333 Patent No. 7256328 Patent No. 7425272

[0006] D. Z. H. Levett et al., "Perioperative cardiopulmonary exercise testing (CPET): consensus clinical guidelines on indications, organization, conduct, and physiological interpretation", British Journal of Anaesthesia, Volume 120, Issue 3, March 2018, Pages 484-500. Japanese Circulation Society guidelines, "Guidelines for Rehabilitation in Cardiovascular Disease (2021 revised edition)", https: / / www. jacr.jp / cms / wp-content / uploads / 2015 / 04 / JCS2021_Makita2.pdf

[0007] In either expiratory gas analysis or blood oxygen concentration measurement, conventionally, measuring ST or ST2 requires exercise with a gradually increasing ramp load, and the exercise time is approximately 15 to 20 minutes. The present invention aims to provide a method and system for estimating pulse rate during ST or ST2, which has a shorter exercise time than conventional ramp loads, a training method in which exercise is performed using the pulse rate estimated by this estimation method as an index, and an exercise instruction device and exercise instruction system that can instruct exercise intensity using an individual's pulse rate as an index.

[0008] The means for solving the problems of the present invention are as follows: 1. A subject is given a fixed load for 2 to 10 minutes that keeps the pulse rate at 75% to 90% of the maximum heart rate, while blood oxygen concentration (SpO ２ ) begins to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ 1. A method for estimating a pulse rate, comprising: determining an initial bending point at which the behavior of the blood oxygen concentration (SpO ) changes; and estimating the pulse rate at the initial bending point or the initial bending point as the pulse rate at the optimal exercise intensity for the subject. 2. A method for estimating a pulse rate, comprising: providing a subject with a fixed load for 2 minutes to 10 minutes at which the pulse rate is 75% to 90% of the maximum heart rate; ２) and simultaneously measure the pulse rate, and measure the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ 2. A method for estimating a pulse rate, comprising a step of determining a second bending point at which the behavior of the pulse rate (pulse rate / pulse rate) changes, and estimating the pulse rate at the second bending point to be the pulse rate at the subject's upper limit exercise intensity. 3. A training method, comprising exercising using the pulse rate estimated by the estimation method described in 1. or 2. as an index. 4. An exercise instruction device, comprising: storage means for storing bioinformation values ​​at the pulse rate estimated by the estimation method described in 1. or 2.; measurement means capable of measuring the bioinformation values; calculation means for calculating exercise intensity by comparing the bioinformation value measured by the measurement means with the bioinformation value at the estimated pulse rate; and instruction means for indicating the exercise intensity calculated by the calculation means. 5. The measuring means is capable of measuring blood oxygen concentration, the instructing means is capable of instructing an exercise load based on information on biological information values ​​from the measuring means, and the calculating means determines the point at which the measured blood oxygen concentration begins to show a downward trend or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ 4. The exercise instruction device according to 4., characterized in that it is capable of calculating a bending point at which the behavior of the blood oxygen concentration (SpO / pulse rate) changes. 6. The exercise instruction device according to 4. or 5., characterized in that it is a wearable device. 7. The exercise instruction device according to 4. or 5., characterized in that it is capable of calculating a bending point at which the behavior of the blood oxygen concentration (SpO ２ a measuring unit that measures the blood oxygen concentration and pulse rate; an indicating unit that indicates the amount of exercise load that is a fixed load that will result in a pulse rate of 75% to 90% of the maximum heart rate; and a unit that indicates the point at which the blood oxygen concentration measurement begins to show a downward trend or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２7. A pulse rate estimation system comprising: a calculation unit for calculating the first bending point at which the behavior of the blood oxygen concentration (SpO2 / pulse rate) changes; and a calculation unit for calculating the first bending point at which the behavior of the blood oxygen concentration (SpO2 / pulse rate) changes; and estimating the pulse rate at the starting point of the decline or the first bending point as the pulse rate at the optimal exercise intensity. ２ 7. The pulse rate estimation system according to 7., wherein the pulse rate at a second bending point where the behavior of the pulse rate (i.e., the maximum exercise intensity) changes is estimated to be the pulse rate at the maximum exercise intensity.

[0009] The present invention makes it possible to estimate the pulse rate at ST or ST2 within 2 to 10 minutes of exercise. When measuring ST or ST2 for a large number of people, such as members of a sports team or students at a physical education university, the measurement time per person can be shortened, thereby increasing the number of people who can be measured per day. While exercise using a ramp load may not reach its physical or muscular limits, some people may feel psychologically overwhelmed by the gradually increasing exercise load and discontinue the exercise, potentially resulting in inaccurate measurements. Because the present invention only requires a fixed-load exercise for a set period of time, it can reduce cases where the true ST or ST2 cannot be estimated because the exerciser gives up midway. Because the present invention can determine the pulse rate at ST or ST2 within 2 to 10 minutes of fixed-load exercise, it allows for more frequent ST or ST2 measurement compared to conventional methods. Because the present invention allows for frequent measurement of one's own ST or ST2, it is a groundbreaking invention for health-conscious individuals who incorporate exercise into their lifestyles, as well as professional athletes and top amateur athletes who require high performance.

[0010] The first method of the present invention, which is a pulse rate estimation method, involves subjecting a subject to a fixed load for 2 to 10 minutes that results in a pulse rate of 75% to 90% of the maximum heart rate, while measuring the blood oxygen concentration (SpO ２ ) begins to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２The method is characterized in that a bending point at which the behavior of the pulse rate (i.e., the heart rate) changes is determined, and the pulse rate at this bending point or the point at which the decline begins is estimated to be the pulse rate at the subject's optimal exercise intensity.

[0011] The second method of the present invention, which is a method for estimating pulse rate, involves subjecting a subject to a fixed load for 2 minutes to 10 minutes that results in a pulse rate of 75% to 90% of the maximum heart rate, while measuring the blood oxygen concentration (SpO ２ ) and simultaneously measure the pulse rate, and calculate the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ determining a bending point at which the behavior of the pulse rate (i.e., the heart rate / pulse rate) changes, and estimating the pulse rate at the bending point to be the pulse rate at the subject's upper limit exercise intensity. In this specification, the expression "A to B (A and B are numbers)" means a numerical range that includes the values ​​of A and B, i.e., A or more and B or less.

[0012] Blood oxygen concentration (SpO ２ ) is the ratio of red blood cell hemoglobin in arterial blood that is bound to oxygen. ２ The blood oxygen concentration can be measured simply by attaching a blood oxygen concentration measuring probe of a measuring device (pulse oximeter) to a fingertip, wrist, etc. The pulse rate estimation method of the present invention is non-invasive and therefore places little strain on the subject.

[0013] The estimation method of the present invention involves subjecting a subject to a fixed load for 2 to 10 minutes at which the pulse rate is 75% to 90% of the maximum heart rate, while measuring the blood oxygen concentration (SpO ２ ) measurement is obtained. At the same time, the pulse rate is measured. ２In addition to pulse rate, one or more biological information values, such as blood pressure, lactate concentration (in blood or sweat), and carbon dioxide concentration in exhaled breath, can also be measured. The estimation method of the present invention involves exercising for 2 to 10 minutes at a fixed load that results in a pulse rate of 75 to 90% of the maximum heart rate. The initial pulse rate at the start of exercise at the fixed load does not have to be 75 to 90% of the maximum heart rate. That is, the estimation method of the present invention does not involve exercising for 2 to 10 minutes after the pulse rate during exercise reaches a target pulse rate (e.g., 75% of the maximum heart rate). It is possible to predict a fixed load that will result in a pulse rate of 75 to 90% of the maximum heart rate based on the subject's exercise habits, and then exercise at the predicted fixed load. However, if the predicted fixed load is outside the range of 75 to 90% of the maximum heart rate, the pulse rate cannot be estimated, which is futile. Therefore, it is preferable to measure a fixed load that will result in a pulse rate of 75 to 90% of the maximum heart rate in advance.

[0014] In the estimation method of the present invention, exercise is performed with a fixed load that results in a pulse rate of 75% to 90% of the maximum heart rate. The maximum heart rate can be a value used as a standard for aerobic exercise, and is generally expressed as 220 - age. However, for elderly people, a value such as 207 - (age x 0.5 to 0.7) can be used. Note that exercise that results in a pulse rate of more than 90% of the maximum heart rate is considered high intensity and places a great burden on the subject.

[0015] In the estimation method of the present invention, the exercise method is not particularly limited, and a treadmill, bicycle ergometer, stepper, etc. can be used. In the estimation method of the present invention, the pulse rate during exercise and the exercise duration are not particularly limited as long as they are within the above-mentioned ranges. The higher the pulse rate and the longer the exercise duration, the more accurately the ST or ST2 pulse rate can be estimated, but the greater the exercise burden during measurement. Therefore, the pulse rate during exercise is preferably 88% or less of the maximum heart rate, more preferably 86% or less, even more preferably 84% or less, even more preferably 82% or less, and even more preferably 80% or less. Furthermore, the exercise duration is preferably 9 minutes or less, more preferably 8 minutes or less, even more preferably 7 minutes or less, even more preferably 6 minutes or less, and even more preferably 5 minutes or less. The combination of pulse rate and exercise duration can be, for example, 2 minutes 30 seconds or more when the heart rate is 75% to 80% of the maximum heart rate, and 2 minutes or more when the heart rate is 80% to 90% of the maximum heart rate. The estimation method of the present invention involves exercise under a fixed load, and the pulse rate during measurement should be kept within a certain range. However, it is preferable to set an upper limit for the pulse rate depending on the subject's gender, age, whether or not they exercise regularly, etc., and if the pulse rate exceeds the set upper limit, it is determined that a heavy load is being placed on the subject, and the measurement is stopped.

[0016] SpO ２ Measurements such as these can be performed continuously, but since measurements are taken while exercising, the measuring device may shift and accurate measurements may not be obtained. Therefore, it is preferable to use values ​​obtained by summarizing measurements taken intermittently at intervals of about 0.1 to 5 seconds as the average or median value for about 1 to 30 seconds. Furthermore, as the exercise time increases, the measured bioinformation values ​​tend to be measured in only one direction, for example, SpO ２ Since blood pressure usually changes only in a decreasing direction and pulse rate only in an increasing direction, it is possible to perform processing that does not use values ​​that show changes opposite to normal, or to not use measurements that deviate by, for example, 10% or more from the average or median of the immediately preceding measurement value or the measurement values ​​of about 2 to 5 points before the measurement.

[0017] The estimation method of the present invention includes, for example, a measuring unit that measures blood oxygen concentration and pulse rate; an instruction unit that indicates an exercise load amount that is a fixed load that causes the pulse rate to be 75% to 90% of the maximum heart rate; and an instruction unit that indicates the starting point of a downward trend in the measured blood oxygen concentration or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ and a calculation unit that calculates the bending point at which the behavior of the pulse rate (pulse rate) changes, and estimates that the pulse rate at the starting point of the decline or the first bending point is the pulse rate at the optimal exercise intensity.

[0018] The estimation system of the present invention may further include a memory unit for storing measured values, a communication unit for exchanging data with the outside, and a display unit for displaying instructions. Furthermore, at least a portion of the memory unit and the calculation unit may be a cloud system in which processing is performed by an external server communicating via the communication unit. Furthermore, the estimation system of the present invention may be implemented by installing an application with a pulse rate estimation function in ST or ST2 on a wearable device such as a smartphone, smartwatch, smart glasses, or earphones, or by connecting a blood oxygen concentration measurement probe. The estimation system of the present invention may be configured by connecting a measurement device such as a pulse oximeter equipped with an instruction unit to a training machine such as a treadmill or bicycle ergometer at a sports gym, either wired or wirelessly, and by measuring the blood oxygen concentration with the measurement unit (measurement device) and instructing the speed, incline, resistance, etc. of the exercise machine, such as the treadmill or bicycle ergometer, so that the exercise load is a fixed load that causes the pulse rate during exercise to be 75% to 90% of the maximum heart rate.

[0019] In the estimation system of the present invention, the pulse rate during exercise is preferably 88% or less of the maximum heart rate, more preferably 86% or less, even more preferably 84% or less, even more preferably 82% or less, and even more preferably 80% or less. Furthermore, the exercise time is preferably 9 minutes or less, more preferably 8 minutes or less, even more preferably 7 minutes or less, even more preferably 6 minutes or less, and even more preferably 5 minutes or less. The combination of pulse rate and exercise time can be, for example, 2 minutes 30 seconds or more when the heart rate is 75% or more but less than 80% of the maximum heart rate, or 2 minutes or more when the heart rate is 80% or more but less than 90% of the maximum heart rate. The estimation system of the present invention can be configured by combining a measuring device such as a pulse oximeter capable of measuring blood oxygen concentration with a training device capable of exercising with a fixed load. This eliminates the need for specialized measuring devices under expert guidance and can be introduced, for example, in sports gyms.

[0020] In the pulse rate estimation method and estimation system of the present invention, the pulse rate at the optimal exercise intensity is calculated based on the blood oxygen concentration (SpO ２ ) begins to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ The pulse rate is estimated as the pulse rate at the first inflection point where the behavior of the heart rate (HR / HR) changes.

[0021] The method for determining the start point of decline and the first bending point is not particularly limited, and various approximation processes, statistical processes, etc. are possible. For example, the following methods can be used: Decline Start Point Determination Method 1-1 (Method 1-1) SpO ２ At the same time, the pulse rate was measured and the SpO ２ The method for determining the start point of decline based on the change over time in SpO2, which involves performing exercise for 2 minutes to 10 minutes with a fixed load that causes the pulse rate to be 75% to 90% of the maximum heart rate, and then measuring the SpO2 at the time when the pulse rate first exceeds the target pulse rate after the first time the target pulse rate is exceeded. ２ The value of SpO ２ The SpO measured value is lower than this reference value for 5 seconds or more. ２ A method for determining the measurement point as the starting point of descent.

[0022] Decline starting point determination method 1-2 (Method 1-2) SpO ２ At the same time, the pulse rate was measured and the SpO ２ The method for determining the start point of decline based on the change over time in SpO2, which involves performing exercise for 2 minutes to 10 minutes with a fixed load that causes the pulse rate to be 75% to 90% of the maximum heart rate, and then measuring the SpO2 at the time when the pulse rate first exceeds the target pulse rate after the first time the target pulse rate is exceeded. ２ The value of SpO ２ SpO in the range where the measured value is lower than this reference value for 5 or more consecutive seconds ２ The intersection of the line connecting the highest and lowest measurement points and the approximation line before the region is determined as the starting point of the descent. If there are two or more highest or lowest measurement points, the first value over time is determined as the measurement point.

[0023] ・Method 1-3 for determining the first bending point (Method 1-3) SpO ２ At the same time, the pulse rate was measured, and the pulse rate was used as the independent variable, SpO ２ divided by the pulse rate (SpO ２ The method uses a dependent variable (maximum heart rate / pulse rate) and involves exercising for 2 to 10 minutes with a fixed load that keeps the pulse rate at 75% to 90% of the maximum heart rate. The method involves combining a regression line 1-1 from the first measurement point to the nth measurement point (n≧2) with a regression line 1-2 from the n+1th measurement point to the Nth measurement point (N≧n+2), and determining the bending point as the intersection of regression lines 1-1 and 1-2 when the sum of squared residuals of regression lines 1-1 and 1-2 is smallest, or the nth measurement point, the n+1th measurement point, or the midpoint (n+0.5) between them when the sum of squared residuals is smallest, or the like.

[0024] Second bending point (upper limit exercise intensity) In the pulse rate estimation method and estimation system of the present invention, the pulse rate at the upper limit exercise intensity is determined by dividing the blood oxygen concentration by the pulse rate (SpO ２ The pulse rate is estimated as the pulse rate at the second inflection point where the behavior of the heart rate (HR / HR) changes.

[0025] The method for determining the second bending point is not particularly limited, and various approximation processes, statistical processes, etc. are possible, but examples thereof include the following methods: Method 2 for determining the second bending point (Method 2): SpO ２ At the same time, the pulse rate was measured, and the pulse rate was used as the independent variable, SpO ２ divided by the pulse rate (SpO ２ / pulse rate) as a dependent variable, and a regression line 2-1 for the mth measurement point (m≧2) from the first measurement point after exceeding the pulse rate at the optimal exercise intensity is combined with a regression line 2-2 for the m+1th measurement point to the Mth measurement point (M≧m+2), and the intersection of the regression lines 2-1 and 2-2 when the sum of the squared residuals of the regression lines 2-1 and 2-2 is smallest, or the mth measurement point, the m+1th measurement point, or the midpoint (m+0.5) between them when the sum of the squared residuals is smallest is determined as the bending point.

[0026] In Methods 1-1 and 1-2, SpO ２ The measured value of SpO2 is the reference value (the value of SpO2 when the pulse rate first exceeds the target pulse rate). ２ The number of seconds during which a value lower than the value (value (a)) is shown should be 5 seconds or more. The longer this number of seconds, the less likely it is that an erroneous determination of the starting point of the decline will be made based on a measurement value that deviates from the trend, but the longer the measurement time, the greater the physical burden on the subject. Therefore, the lower limit of this number of seconds is preferably 8 seconds or more, more preferably 10 seconds or more, and the upper limit of this number of seconds is preferably 60 seconds or less, more preferably 50 seconds or less, and even more preferably 40 seconds or less.

[0027] In addition, to prevent erroneous judgment due to a single measurement error, it is preferable to make a judgment based on two or more consecutive measurement values. ２ When the SpO measurement is taken as an average value for 1 to 30 seconds, ２ It is preferable that the value of the number of seconds for calculating the measured value (average value) × (number of measurements - 1) is 5 seconds or more, and that two or more consecutive measurement points have values ​​lower than the reference value.

[0028] In methods 1-3 and 2, if two minutes or more have elapsed since the start of exercise with a fixed load, and the sum of squared residuals of regression lines A and B1 is smallest for the combination of regression line A for the first measurement point to the xth measurement point and regression line B1 for the x+1th measurement point to the xth measurement point, and if the sum of squared residuals of regression lines A and B1 is smallest for the combination of regression line A for the first measurement point to the xth measurement point and regression line B2 for the x+1th measurement point to the x+pth measurement point, which are obtained by continuing exercise, the bending point can be determined and further exercise can be stopped. When exercise is stopped midway in this way, X is preferably 5 or more, and p is preferably 2 or more. Furthermore, the measurement times for the 1st to xth and x+1th to xth measurements are preferably 20 seconds or more, more preferably 30 seconds or more, and even more preferably 40 seconds or more. Furthermore, the measurement time from the Xth to the X+pth times is preferably 10 seconds or more, more preferably 15 seconds or more, and even more preferably 20 seconds or more.

[0029] Training Method: The training method of the present invention is characterized in that exercise is performed using the pulse rate at the exercise intensity estimated by the above estimation method as an index. The exercise intensity may be either an optimal exercise intensity or an upper limit exercise intensity. The estimation method of the present invention makes it possible to estimate the pulse rate at the optimal exercise intensity or the upper limit exercise intensity. Furthermore, since the pulse rate at the estimated optimal exercise intensity is similar to the pulse rate at an exercise intensity at AT, and the pulse rate at the estimated upper limit exercise intensity is similar to the pulse rate at an exercise intensity at RCP, a training method in which exercise is performed using the pulse rate at these exercise intensities as an index makes it possible to efficiently improve physical fitness.

[0030] Exercise Instruction Device The exercise instruction device of the present invention is characterized by comprising: a storage means for storing a biometric information value at a pulse rate estimated by the estimation method of the present invention; a measurement means for measuring the biometric information value; and an instruction means for comparing the biometric information value measured by the measurement means with the biometric information value at the estimated pulse rate and instructing an exercise intensity. The exercise intensity may be either an optimal exercise intensity or an upper limit exercise intensity, or both. The exercise instruction device of the present invention may also comprise a storage means such as a memory, a communication means, a display means, a calculation means such as a CPU, a battery, etc. Furthermore, at least a portion of the storage means and the calculation means may be processed by an external server communicating through a communication unit. The form of the exercise instruction device of the present invention is not particularly limited. For example, it may be built into a training machine or may be an external terminal connected to the training machine. For example, it may be a smartphone, a smartwatch, smartglasses, earphones, etc., which can implement the above means by installing an application. Among these, a wearable terminal such as a smartwatch or smartglasses is preferred.

[0031] In the exercise instruction device of the present invention, the biological information values ​​measured and stored include SpO ２ In addition to the pulse rate, blood pressure, lactic acid concentration (in blood, sweat), carbon dioxide concentration in exhaled air, etc. may be used, and one or more of these may be used. Among these, SpO ２ It is preferable that the exercise instruction device of the present invention measures and stores the current pulse rate and pulse rate. The exercise instruction device of the present invention can calculate the difference between the current pulse rate and the estimated pulse rate by comparing the bioinformation value of the estimated pulse rate stored in the storage means with the bioinformation value measured by the measurement means using the calculation means, thereby calculating an exercise intensity suitable for the purpose. In this case, it is preferable that the estimated pulse rate can be used as an index to set weak, equal, strong, etc. as the exercise intensity. This allows the user to select an exercise intensity suitable for the purpose depending on their physical condition, the number of days until a game, etc., etc. Then, by exercising at the exercise intensity instructed by the exercise instruction device of the present invention, the user can train very efficiently.

[0032] Furthermore, the exercise instruction device of the present invention is characterized in that the measuring means is ２ The device is capable of measuring the blood oxygen concentration and pulse rate, and the indicating means is capable of indicating the amount of exercise load based on the information. The calculating means calculates the point at which the measured blood oxygen concentration begins to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ It is preferable that the exercise instruction device be capable of calculating the inflection point at which the behavior of the pulse rate (ST / pulse rate) changes. Such an exercise instruction device can estimate the pulse rate at the user's optimal exercise intensity and even the pulse rate at the upper limit of exercise intensity by instructing the user to exercise at a fixed load that results in a pulse rate of 75% to 90% of the maximum heart rate. Therefore, for example, even if physical ability improves after continuing exercise for a while at an intensity that uses the estimated pulse rate instructed by the exercise instruction device of the present invention as an index, and then the user no longer expects much improvement in physical ability at this exercise intensity, the pulse rate at the latest ST or ST2 can be calculated and the user can exercise at an exercise intensity with a higher load.

[0033] (Example) Exercise load method Equipment used: Ergometer Load method: Fixed load method Ergometer settings - crank rotation speed 60 rpm Saddle position so that the subject's knees are slightly bent when the pedals reach the bottom Rest condition - rest in a seated position for 2 minutes (seat on the ergometer) Warm-up condition - 5 minutes at 50 watts Stop condition - end the load when one of the following conditions is met: 1) When 60 rpm exercise can no longer be maintained due to lower limb fatigue 2) When the tester decides to stop the test 3) SpO ２ Or when the pulse rate exceeds the set measurement range Load unit: watt

[0034] Loading method: Ramp loading method Ergometer settings - crank rotation speed 60 rpm Saddle position so that the subject's knees are slightly bent when the pedals reach the bottom Rest conditions - rest in a seated position for 2 minutes (sitting on the ergometer) Warm-up conditions - 50 watts for 5 minutes Exercise load conditions - ramp load increase rate 10 watts / min Stop conditions - load ends when one of the following conditions is met 1) When 60 rpm exercise can no longer be maintained due to lower limb fatigue 2) When the tester decides to stop the test 3) SpO ２ Or when the pulse rate exceeds the set measurement range Load unit: watt

[0035] (SpO ２ and pulse rate) Blood oxygen concentration (SpO ２ ) and pulse rate were measured. ２ The SpO and pulse rate were measured at 4-second intervals and averaged over 20 seconds. ２ The test was performed with the range of 96-100% and the upper pulse rate limit set at 160 beats / min.

[0036] Experiment 1: Subjects A to E were given a ramp load while SpO ２ The subjects A to E were all under 50 years old, and their maximum heart rate was 220 minus their age. One week after the measurement using the ramp load, the SpO2 was measured in the same manner except that a fixed load was applied for 4 minutes at which the pulse rate was 80% of the maximum heart rate. ２ The fixed load at which the heart rate was 80% of the maximum heart rate was determined from the pulse rate during exercise using a ramp load.

[0037] Determination of the inflection point SpO ２ At the same time, the pulse rate was measured, and the pulse rate was used as the independent variable, SpO ２ divided by the pulse rate (SpO ２The pulse rate at the optimal exercise intensity (ST) was estimated using the dependent variable, and the regression line 1-1 from the first measurement point to the Nth (N≧2) measurement point was combined with the regression line 1-2 from the N+1th measurement point to the last measurement point, where the sum of the residual sums of squares of the two regression lines 1-1 and 1-2 was smallest, as the first bending point, and the pulse rate at the optimal exercise intensity (ST) was estimated.

[0038] From the data of the measurement points after the pulse rate at the estimated optimal exercise intensity (N+1st to the last measurement point), the pulse rate at the upper limit exercise intensity (ST2) was estimated by combining a regression line 2-1 for the pulse rate at the optimal exercise intensity from (N+1) to the Mth (M≧2) measurement point and a regression line 2-2 for the pulse rate at the optimal exercise intensity from the (N+1) to the Mth (M≧2) measurement point, and the (N+M+2) measurement point where the sum of the residual sums of squares of the two regression lines 2-1 and 2-2 was smallest was set as the second bending point.

[0039] Table 1 shows the pulse rates at the optimum exercise intensity (ST) and upper limit exercise intensity (ST2) estimated for fixed load exercise and ramp load exercise.

[0040] For all subjects, the pulse rates estimated at the optimal exercise intensity and upper limit exercise intensity using fixed load exercise were very close to those estimated at the optimal exercise intensity and upper limit exercise intensity using ramp load exercise. In other words, it was confirmed that the estimation method of the present invention can estimate pulse rates at ST or ST2 using fixed load exercise that are almost equivalent to those obtained using ramp load exercise.

[0041] Experiment 2: Subject E (male, 47 years old) was given a fixed load of 70% and 75% of the maximum heart rate, and the same SpO2 measurements were performed as above. ２ The obtained SpO ２For the pulse rate, the pulse rate at the optimal exercise intensity (ST) and the pulse rate at the upper limit of exercise intensity (ST2) were estimated by changing the data (fixed load time) used. Table 2 shows the difference between the estimated pulse rates at ST and ST2 and the reference pulse rate, using the pulse rates at ST and ST2 estimated from the results of a 4-minute 80% fixed load as the reference. Note that ST and ST2 for the same exercise intensity were estimated from the same data; for example, the first bending point (ST) and second bending point (ST2) were estimated from the data of the first minute of a 4-minute exercise for a 1-minute fixed load time, and from the data of the first 2 minutes of a 4-minute exercise for a 2-minute fixed load time.

[0042]

[0043] When performing fixed-load exercise with a pulse rate of 70% of the maximum heart rate, the difference between the pulse rate at the estimated exercise intensity and the pulse rate at an exercise intensity estimated from a fixed load of 80% for 4 minutes was large (more than 20 beats per minute), resulting in poor accuracy in estimating exercise intensity. When performing fixed-load exercise with a pulse rate of 75% of the maximum heart rate, the difference between the pulse rate at the estimated exercise intensity and the pulse rate at an exercise intensity estimated from a fixed load of 80% for 4 minutes was kept within 16 beats per minute for exercise durations of 2 minutes or more, and within 14 beats per minute for exercise durations of 2 minutes and 30 seconds or more. When performing fixed-load exercise with a pulse rate of 80% of the maximum heart rate, the difference between the pulse rate at the exercise intensity estimated from a fixed load of 80% for 4 minutes or more was kept within 1 beat per minute at the optimal exercise intensity for exercise durations of 2 minutes or more, and within 10 beats per minute at the upper limit of exercise intensity. It was also confirmed that the longer the exercise duration, the smaller the difference in pulse rate, improving estimation accuracy.

Claims

1. Subjects were given a fixed load that kept their pulse rate at 75% to 90% of their maximum heart rate for 2 to 10 minutes, while blood oxygen concentration (SpO ２ ) begins to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ a pulse rate at which the subject's heart rate (heart rate / heart rate) changes, and the pulse rate at the point where the decline begins or the first bending point is estimated to be the subject's pulse rate at the optimal exercise intensity.

2. Subjects are given a fixed load that keeps their pulse rate at 75% to 90% of their maximum heart rate for 2 to 10 minutes, while blood oxygen concentration (SpO ２ ), and simultaneously measure the pulse rate, and measure the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ determining a second bending point at which a behavior of the pulse rate (pulse rate) changes, and estimating the pulse rate at the second bending point to be the pulse rate at the subject's upper limit exercise intensity.

3. A training method characterized by performing exercise using the pulse rate estimated by the estimation method according to claim 1 or 2 as an index.

4. An exercise instruction device comprising: a storage means for storing a bioinformation value at a pulse rate estimated by the estimation method of claim 1 or 2; a measurement means capable of measuring said bioinformation value; a calculation means for calculating exercise intensity by comparing the bioinformation value measured by said measurement means with the bioinformation value at the estimated pulse rate; and an indication means for indicating the exercise intensity calculated by said calculation means.

5. The measuring means is capable of measuring blood oxygen concentration, the instructing means is capable of instructing the exercise load based on information on the biological information value from the measuring means, and the calculating means calculates the point at which the measured blood oxygen concentration starts to show a downward trend, or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ 5. The exercise instruction device according to claim 4, wherein the device is capable of calculating a bending point at which the behavior of the heart rate (i.e., the heart rate) changes.

6. The exercise instruction device according to claim 4, which is a wearable terminal.

7. Blood oxygen concentration (SpO ２ a measuring unit that measures the blood oxygen concentration and pulse rate; an indicating unit that indicates the amount of exercise load that is a fixed load that will result in a pulse rate of 75% to 90% of the maximum heart rate; and a unit that indicates the point at which the blood oxygen concentration measurement begins to show a downward trend or the value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ and a calculation unit that calculates the first bending point at which the behavior of the pulse rate (i.e., the pulse rate) changes, and estimates the pulse rate at the starting point of the decline or the first bending point to be the pulse rate at the optimal exercise intensity.

8. The value obtained by dividing the blood oxygen concentration by the pulse rate (SpO ２ 8. The pulse rate estimation system according to claim 7, wherein the pulse rate at a second bending point where the behavior of the pulse rate (pulse rate) changes is estimated to be the pulse rate at the upper limit of exercise intensity.

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