Mga Formula sa Power sa Cycling

Formula:

Halimbawa ng Pagkalkula:

Implementation sa JavaScript:

function calculateTSS(durationSeconds, normalizedPower, ftp) {
  const intensityFactor = normalizedPower / ftp;
  const tss = (durationSeconds * normalizedPower * intensityFactor) / (ftp * 3600) * 100;
  return Math.round(tss);
}

// Halimbawa ng paggamit:
const tss = calculateTSS(7200, 235, 250);
// Returns: 177

Algorithm (30-segundong rolling average):

Bakit ika-4 na Power?

Ang quartic (4th power) na ugnayan ay sumasalamin sa non-linear na physiological cost ng mga pabagu-bagong effort. Ang isang ride na may mga surge at recovery ay mas nakakapagod kaysa sa steady power sa parehong average.

Implementation sa JavaScript:

function calculateNormalizedPower(powerData) {
  // Ang powerData ay array ng 1-segundong power values

  // Step 1: Kalkulahin ang 30-segundong rolling averages
  const rollingAvgs = [];
  for (let i = 29; i < powerData.length; i++) {
    const window = powerData.slice(i - 29, i + 1);
    const avg = window.reduce((sum, p) => sum + p, 0) / 30;
    rollingAvgs.push(avg);
  }

  // Step 2: Itaas sa ika-4 na power
  const powered = rollingAvgs.map(p => Math.pow(p, 4));

  // Step 3: Average ng ika-4 na power
  const avgPowered = powered.reduce((sum, p) => sum + p, 0) / powered.length;

  // Step 4: Kunin ang 4th root
  const np = Math.pow(avgPowered, 0.25);

  return Math.round(np);
}

// Halimbawa ng paggamit:
const powerData = [/* 1-segundong power array */];
const np = calculateNormalizedPower(powerData);
// Returns: NP sa watts

Formula:

Mga Range ng Interpretasyon:

Range ng IF	Antas ng Effort	Halimbawa ng Workout
< 0.75	Recovery / Madali	Active recovery ride, Zone 1-2
0.75 - 0.85	Endurance	Mahabang steady ride, aerobic base
0.85 - 0.95	Tempo	Sweet spot training, tempo intervals
0.95 - 1.05	Threshold	FTP intervals, time trial effort
1.05 - 1.15	VO₂max	5-minutong interval, criterium race
> 1.15	Anaerobic	Maikling sprint, attack, MTB burst

Halimbawa ng Pagkalkula:

function calculateIF(normalizedPower, ftp) {
  return (normalizedPower / ftp).toFixed(2);
}

// Halimbawa:
const if_value = calculateIF(235, 250);
// Returns: 0.94

Formula:

Interpretasyon base sa Disiplina:

Disiplina	Karaniwang VI	Kahulugan
Road TT / Steady Effort	1.00 - 1.05	Napaka-consistent na power, maayos na pacing
Road Racing	1.05 - 1.10	May ilang mga surge, sa pangkalahatan ay steady
Criterium	1.10 - 1.20	Madalas na acceleration at attack
Mountain Bike XC	1.15 - 1.30+	Lubos na nagbabago-bago, laging may surge

Halimbawa ng Pagkalkula:

function calculateVI(normalizedPower, averagePower) {
  return (normalizedPower / averagePower).toFixed(2);
}

// Halimbawa:
const vi_road = calculateVI(240, 230);  // Returns: 1.04
const vi_mtb = calculateVI(285, 235);   // Returns: 1.21

Mga Formula (Exponentially Weighted Moving Averages):

Mga Definisyon ng Metric:

• CTL (Chronic Training Load): 42-araw na exponentially weighted average - kumakatawan sa fitness.
• ATL (Acute Training Load): 7-araw na exponentially weighted average - kumakatawan sa pagkapagod (fatigue).
• TSB (Training Stress Balance): Form = Fitness - Fatigue

Halimbawa ng Pagkalkula (7-Araw na Training Block):

Interpretasyon ng TSB:

Range ng TSB	Status	Aksyon
< -30	High Risk	Overtraining warning - bawasan ang load
-30 hanggang -10	Training Hard	Bumubuo ng fitness, bantayan ang recovery
-10 hanggang +5	Optimal	Normal training zone
+5 hanggang +15	Race Ready	Peak form - pwede nang mag-race ngayong weekend
> +25	Detraining	Nawawala ang fitness - dagdagan ang load

Implementation sa JavaScript:

function calculatePMC(workouts) {
  // workouts = [{date: "YYYY-MM-DD", tss: number}, ...]
  let ctl = 0, atl = 0;
  const results = [];

  workouts.forEach(workout => {
    // I-update ang CTL (42-day time constant)
    ctl = ctl + (workout.tss - ctl) / 42;

    // I-update ang ATL (7-day time constant)
    atl = atl + (workout.tss - atl) / 7;

    // Kalkulahin ang TSB (kahapong CTL - ngayong ATL para sa traditional na kalkulasyon)
    // Para mas simple dito, gamit ang kasalukuyang mga halaga
    const tsb = ctl - atl;

    results.push({
      date: workout.date,
      tss: workout.tss,
      ctl: Math.round(ctl * 10) / 10,
      atl: Math.round(atl * 10) / 10,
      tsb: Math.round(tsb * 10) / 10,
      status: getTSBStatus(tsb)
    });
  });

  return results;
}

function getTSBStatus(tsb) {
  if (tsb < -30) return "High Risk";
  if (tsb < -10) return "Training Hard";
  if (tsb < 5) return "Optimal";
  if (tsb < 15) return "Race Ready";
  return "Detraining";
}

// Halimbawa ng paggamit:
const workouts = [
  {date: "2025-01-01", tss: 100},
  {date: "2025-01-02", tss: 50},
  {date: "2025-01-03", tss: 120},
  // ... higit pang workouts
];

const pmc = calculatePMC(workouts);
// Returns array na may CTL, ATL, TSB para sa bawat araw

Kumpletong Formula:

Mga Formula ng Bawat Component:

Mga Constant at Variable:

• CdA = Drag coefficient × frontal area (m²)
  • Karaniwang road bike hoods: 0.35-0.40 m²
  • Drops: 0.32-0.37 m²
  • TT position: 0.20-0.25 m²
• ρ = Densidad ng hangin (1.225 kg/m³ sa sea level, 15°C)
• V = Bilis o Velocity (m/s)
• m = Kabuuang bigat (rider + bike, kg)
• g = Gravity (9.81 m/s²)
• θ = Anggulo ng gradient (radians o degrees na nai-convert)
• Crr = Rolling resistance coefficient (~0.004 para sa magandang road tires)
• a = Acceleration (m/s²)

Halimbawa ng Pagkalkula (Flat Road TT):

Implementation sa JavaScript:

function calculatePowerRequired(params) {
  const {
    velocityKph,
    CdA = 0.32,              // m²
    rho = 1.225,             // kg/m³
    mass = 83,               // kg (rider + bike)
    gradientPercent = 0,     // %
    Crr = 0.004,             // rolling resistance
    accelerationMps2 = 0     // m/s²
  } = params;

  // I-convert ang velocity sa m/s
  const V = velocityKph / 3.6;

  // I-convert ang gradient sa anggulo
  const theta = Math.atan(gradientPercent / 100);

  // Kalkulahin ang bawat component
  const P_aero = CdA * 0.5 * rho * Math.pow(V, 3);
  const P_gravity = mass * 9.81 * Math.sin(theta) * V;
  const P_rolling = Crr * mass * 9.81 * Math.cos(theta) * V;
  const P_kinetic = mass * accelerationMps2 * V;

  return {
    total: Math.round(P_aero + P_gravity + P_rolling + P_kinetic),
    aero: Math.round(P_aero),
    gravity: Math.round(P_gravity),
    rolling: Math.round(P_rolling),
    kinetic: Math.round(P_kinetic)
  };
}

// Halimbawa: TT sa 40 km/h
const power_tt = calculatePowerRequired({
  velocityKph: 40,
  CdA: 0.22,
  mass: 83,
  gradientPercent: 0
});
// Returns: { total: 221, aero: 185, gravity: 0, rolling: 36, kinetic: 0 }

// Halimbawa: 8% climb sa 15 km/h
const power_climb = calculatePowerRequired({
  velocityKph: 15,
  CdA: 0.38,
  mass: 75,
  gradientPercent: 8
});
// Returns: { total: 265, aero: 27, gravity: 244, rolling: 11, kinetic: 0 }