A Performance Management Chart (PMC), popularized by TrainingPeaks, summarizes an endurance athlete's training history on a single shared time axis. Two exponentially-smoothed lines track Chronic Training Load (CTL, "fitness", ~42-day time constant) and Acute Training Load (ATL, "fatigue", ~7-day time constant), while a filled area or band shows Training Stress Balance (TSB, "form" = CTL − ATL) above and below a zero baseline. Daily Training Stress Score (TSS) values appear as points or thin vertical bars, giving the raw workout intensity behind the smoothed trends. The chart reveals whether an athlete is building fitness, accumulating fatigue, or freshening up (positive form) for a target event.
""" anyplot.ai
line-training-load-pmc: Training Load Performance Management Chart
Library: plotly 6.8.0 | Python 3.13.13
Quality: 86/100 | Created: 2026-06-13
"""
import os
import numpy as np
import pandas as pd
import plotly.graph_objects as go
from plotly.subplots import make_subplots
# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
GRID = "rgba(26,26,23,0.15)" if THEME == "light" else "rgba(240,239,232,0.15)"
# Imprint palette — semantic mapping for training metrics
FITNESS_GREEN = "#009E73" # CTL / positive form — Imprint position 1 (growth/fitness)
FATIGUE_RED = "#AE3030" # ATL / negative form — Imprint position 5 (stress/fatigue)
TSS_BLUE = "#4467A3" # Daily TSS bars — Imprint position 3 (neutral input)
# Data — 180-day periodized training block with build/recovery cycles and end taper
np.random.seed(42)
n_days = 180
dates = pd.date_range("2025-01-01", periods=n_days, freq="D").strftime("%Y-%m-%d").tolist()
tss = np.zeros(n_days)
for i in range(n_days):
day_of_week = i % 7
week_phase = (i // 7) % 4 # 0,1 = base build; 2 = peak build; 3 = recovery
if day_of_week == 6: # Sunday rest
tss[i] = 0.0
elif i >= 160: # Taper for peak event at day 180
tss[i] = np.random.uniform(20, 60) * max(0.3, 1 - (i - 160) / 25)
elif week_phase == 3: # Recovery week
tss[i] = np.random.uniform(25, 60)
elif week_phase == 2: # Peak build week
tss[i] = np.random.uniform(90, 155)
else: # Base build
tss[i] = np.random.uniform(55, 115)
# Standard PMC formulas: EWMA with 42-day (CTL) and 7-day (ATL) time constants
ctl_alpha = 1 - np.exp(-1 / 42)
atl_alpha = 1 - np.exp(-1 / 7)
ctl = np.zeros(n_days)
atl = np.zeros(n_days)
tsb = np.zeros(n_days)
ctl[0] = tss[0] * 0.5
atl[0] = tss[0] * 0.7
for i in range(1, n_days):
tsb[i] = ctl[i - 1] - atl[i - 1] # Form = yesterday's fitness − yesterday's fatigue
ctl[i] = ctl[i - 1] + (tss[i] - ctl[i - 1]) * ctl_alpha
atl[i] = atl[i - 1] + (tss[i] - atl[i - 1]) * atl_alpha
# Plot — secondary y-axis keeps TSB (±50) readable against CTL/ATL (0–150)
fig = make_subplots(specs=[[{"secondary_y": True}]])
# Daily TSS bars (primary axis — background layer, raw workout stress)
fig.add_trace(
go.Bar(
x=dates,
y=tss,
name="Daily TSS",
width=86400000, # one day in ms — fills each slot without gaps
marker={"color": TSS_BLUE, "opacity": 0.28, "line": {"width": 0}},
hovertemplate="%{x|%b %d}: TSS %{y:.0f}<extra></extra>",
),
secondary_y=False,
)
# TSB positive fill — fresh / "in form" (secondary axis)
fig.add_trace(
go.Scatter(
x=dates,
y=np.where(tsb >= 0, tsb, 0.0),
fill="tozeroy",
fillcolor="rgba(0,158,115,0.18)",
line={"width": 0},
mode="lines",
showlegend=False,
hoverinfo="skip",
),
secondary_y=True,
)
# TSB negative fill — fatigued (secondary axis)
fig.add_trace(
go.Scatter(
x=dates,
y=np.where(tsb <= 0, tsb, 0.0),
fill="tozeroy",
fillcolor="rgba(174,48,48,0.18)",
line={"width": 0},
mode="lines",
showlegend=False,
hoverinfo="skip",
),
secondary_y=True,
)
# TSB = 0 reference — separates "fresh" from "fatigued" zones (secondary axis)
fig.add_trace(
go.Scatter(
x=[dates[0], dates[-1]],
y=[0, 0],
mode="lines",
line={"color": INK_SOFT, "width": 1.0, "dash": "dot"},
showlegend=False,
hoverinfo="skip",
),
secondary_y=True,
)
# ATL — Acute Training Load / Fatigue (primary axis, dashed for color-blind accessibility)
fig.add_trace(
go.Scatter(
x=dates,
y=atl,
name="Fatigue (ATL)",
line={"color": FATIGUE_RED, "width": 2.5, "dash": "dot"},
mode="lines",
hovertemplate="%{x|%b %d}: ATL %{y:.1f}<extra></extra>",
),
secondary_y=False,
)
# CTL — Chronic Training Load / Fitness (primary axis, drawn on top)
fig.add_trace(
go.Scatter(
x=dates,
y=ctl,
name="Fitness (CTL)",
line={"color": FITNESS_GREEN, "width": 3.0},
mode="lines",
hovertemplate="%{x|%b %d}: CTL %{y:.1f}<extra></extra>",
),
secondary_y=False,
)
# TSB — Form line with legend entry (secondary axis, 2px for better visibility)
fig.add_trace(
go.Scatter(
x=dates,
y=tsb,
name="Form (TSB)",
line={"color": INK_SOFT, "width": 2.0},
mode="lines",
hovertemplate="%{x|%b %d}: TSB %{y:.1f}<extra></extra>",
),
secondary_y=True,
)
# Title with scaled font for the long string (73 chars → ratio 67/73)
title = "Training Load PMC · line-training-load-pmc · python · plotly · anyplot.ai"
n = len(title)
title_fontsize = max(11, round(16 * 67 / n)) if n > 67 else 16
fig.update_layout(
autosize=False,
paper_bgcolor=PAGE_BG,
plot_bgcolor=PAGE_BG,
font={"color": INK},
title={"text": title, "font": {"size": title_fontsize, "color": INK}, "x": 0.02, "xanchor": "left"},
margin={"l": 80, "r": 80, "t": 80, "b": 90},
legend={
"bgcolor": ELEVATED_BG,
"bordercolor": INK_SOFT,
"borderwidth": 1,
"font": {"color": INK_SOFT, "size": 10},
"x": 0.99,
"y": 0.97,
"xanchor": "right",
"yanchor": "top",
},
barmode="overlay",
)
# Primary y-axis: Training Load (TSS bars, CTL, ATL — all non-negative)
fig.update_yaxes(
title={"text": "Training Load (TSS · CTL · ATL)", "font": {"color": INK, "size": 12}},
tickfont={"color": INK_SOFT, "size": 10},
gridcolor=GRID,
showline=True,
linecolor=INK_SOFT,
mirror=False,
zeroline=False,
rangemode="tozero",
secondary_y=False,
)
# Secondary y-axis: Form / TSB (oscillates around 0 — no grid to avoid doubling)
fig.update_yaxes(
title={"text": "Form (TSB)", "font": {"color": INK, "size": 12}},
tickfont={"color": INK_SOFT, "size": 10},
showgrid=False,
zeroline=False,
showline=True,
linecolor=INK_SOFT,
mirror=False,
secondary_y=True,
)
# x-axis: shared date axis with monthly ticks
fig.update_xaxes(
tickfont={"color": INK_SOFT, "size": 10},
showline=True,
linecolor=INK_SOFT,
mirror=False,
showgrid=False,
dtick="M1",
tickformat="%b '%y",
)
# Save
fig.write_image(f"plot-{THEME}.png", width=800, height=450, scale=4)
fig.write_html(f"plot-{THEME}.html", include_plotlyjs="cdn")
Part of Training Load Performance Management Chart on anyplot.ai.