Техническая справка и формулы

Формула:

Реализация на JavaScript:

function calculateCadence(stepCount, timeSeconds) {
  return (stepCount / timeSeconds) * 60;
}

// Example:
const cadence = calculateCadence(180, 60);
// Returns: 180 SPM

Формула:

Реализация на JavaScript:

function calculateStrideLength(distanceMeters, stepCount) {
  // Stride length is distance / number of stride pairs (left+right)
  return distanceMeters / (stepCount / 2);
}

// Example (1000m, 800 steps):
const strideLength = calculateStrideLength(1000, 800);
// Returns: 2.50 м/шаг

Формула:

Реализация на JavaScript:

function calculateVelocity(cadence, strideLength) {
  // cadence in steps per minute (SPM), strideLength in meters
  return (cadence / 60) * strideLength;
}

// Пример (Каденс 180, Длина шага 1.25м):
const velocity = calculateVelocity(180, 1.25);
// Возвращает: 3.75 м/с (4:27/км)

Формула:

Реализация на JavaScript:

function calculateStrideIndex(velocity, strideLength) {
  return velocity * strideLength;
}

// Пример:
const si = calculateStrideIndex(3.75, 1.25);
// Возвращает: 4.69

Реализация на JavaScript:

function calculateCRSRegression(distances, times) {
  // Linear regression: distance = a + b*time
  const n = distances.length;
  const sumX = times.reduce((a, b) => a + b, 0);
  const sumY = distances.reduce((a, b) => a + b, 0);
  const sumXY = times.reduce((sum, x, i) => sum + x * distances[i], 0);
  const sumXX = times.reduce((sum, x) => sum + x * x, 0);

  const slope = (n * sumXY - sumX * sumY) / (n * sumXX - sumX * sumX);
  const intercept = (sumY - slope * sumX) / n;

  return {
    crs: slope, // Критическая скорость бега (m/s)
    anaerobic_capacity: intercept // Анаэробная емкость (м)
  };
}

// Пример с несколькими тестовыми дистанциями:
const distances = [1200, 2400, 3600];
const times = [252, 540, 864]; // в секундах
const result = calculateCRSRegression(distances, times);
// Возвращает: { crs: 3.92, anaerobic_capacity: 211.7 }

Реализация на JavaScript:

function calculateIntensityFactor(actualPaceMinKm, thresholdPaceMinKm) {
  // Convert pace strings "mm:ss" to seconds if necessary
  const actualSecs = typeof actualPaceMinKm === 'string' ? timeToSeconds(actualPaceMinKm) : actualPaceMinKm;
  const thresholdSecs = typeof thresholdPaceMinKm === 'string' ? timeToSeconds(thresholdPaceMinKm) : thresholdPaceMinKm;

  // IF is Threshold Pace / Actual Pace (faster pace = smaller seconds value)
  return thresholdSecs / actualSecs;
}

// Example:
const if_value = calculateIntensityFactor("4:45", "4:15");
// Returns: 0.895 (running at 89.5% of threshold)

Реализация на JavaScript:

function analyzePaceConsistency(segments) {
  const paces = segments.map(kilometer => kilometer.distance / kilometer.time);
  const avgPace = paces.reduce((a, b) => a + b) / paces.length;

  const variance = paces.reduce((sum, pace) =>
    sum + Math.pow(pace - avgPace, 2), 0) / paces.length;
  const stdDev = Math.sqrt(variance);
  const coefficientOfVariation = (stdDev / avgPace) * 100;

  return {
    avgPace,
    stdDev,
    coefficientOfVariation,
    consistency: coefficientOfVariation < 5 ? "Отлично" :
                 coefficientOfVariation < 10 ? "Хорошо" :
                 coefficientOfVariation < 15 ? "Умеренно" : "Изменчиво"
  };
}

// Example:
const segments = [
  { distance: 100, time: 70 },
  { distance: 100, time: 72 },
  { distance: 100, time: 71 },
  // ...
];
const analysis = analyzePaceConsistency(segments);
// Returns: { avgPace: 1.41, stdDev: 0.02, coefficientOfVariation: 1.4, consistency: "Отлично" }

Реализация на JavaScript:

function detectFatigue(segments) {
  const firstThird = segments.slice(0, Math.floor(segments.length/3));
  const lastThird = segments.slice(-Math.floor(segments.length/3));

  const firstThirdAvg = firstThird.reduce((sum, kilometer) =>
    sum + kilometer.strideCount, 0) / firstThird.length;
  const lastThirdAvg = lastThird.reduce((sum, kilometer) =>
    sum + kilometer.strideCount, 0) / lastThird.length;

  const strideCountIncrease = ((lastThirdAvg - firstThirdAvg) / firstThirdAvg) * 100;

  return {
    firstThirdAvg: Math.round(firstThirdAvg * 10) / 10,
    lastThirdAvg: Math.round(lastThirdAvg * 10) / 10,
    percentIncrease: Math.round(strideCountIncrease * 10) / 10,
    fatigueLevel: strideCountIncrease < 5 ? "Минимальная" :
                  strideCountIncrease < 10 ? "Умеренная" :
                  strideCountIncrease < 20 ? "Значительная" : "Сильная"
  };
}

// Example:
const segments = [
  { strideCount: 14 }, { strideCount: 14 }, { strideCount: 15 },
  { strideCount: 15 }, { strideCount: 16 }, { strideCount: 16 },
  { strideCount: 17 }, { strideCount: 18 }, { strideCount: 18 }
];
const fatigue = detectFatigue(segments);
// Returns: { firstThirdAvg: 14.3, lastThirdAvg: 17.7, percentIncrease: 23.8, fatigueLevel: "Сильная" }