Loom
Every ride has a physiological shape. Loom renders that shape as color and light, weaving each session into a continuous textile of athletic development. Your season becomes visible without reading a single number.
A textile of athletic development
Loom renders each ride as a single vertical strip of color, arranged chronologically left to right. Within each strip, the horizontal bands map to the seven PTA thresholds, from neuromuscular power at the top (gold) to sustained threshold at the bottom (deep plum). Your season becomes a woven fabric of color and light.
The visualization borrows its structure from Ed Hawkins' warming stripes and applies it to individual athletic performance data. Where Hawkins used one stripe per year to show a planetary trend, Loom uses one strip per ride to show an athletic one. The design story behind this decision is told in The Shape of the Heat.
What the heat means
Each strip in Loom carries four independent visual channels. Together they encode the physiological state of the athlete at the time of each ride.
The veil manifests in three visible ways. Sharpness degrades as fatigue accumulates, blurring the crisp edges of a strip. Echoes let the residue of a hard session linger into subsequent strips. Bleed occurs when fatigue erodes the boundary between rides entirely. Clean separation between strips means the body is absorbing the work.
Brightness encodes fitness (chronic training load).
Veil encodes fatigue (training stress balance).
Clarity encodes peak form (the net readiness that emerges from their interplay).
These four channels are independent signals that combine to produce the visible character of each strip. They correspond to the physiological dimensions of the Banister performance model.
Patterns, not numbers
Loom makes several things visible immediately without any numerical literacy.
Consistency. Dense, closely-spaced strips mean regular riding. Gaps appear as literal empty space. A two-week break is visible without counting days.
Fitness trajectory. A sequence that grows brighter over time is a rider building fitness. A sequence that dims is fitness eroding. The gradient tells the story.
Fatigue cycles. The veil accumulates over hard days, softening each strip. After rest, clarity returns. Overtraining appears as sustained veiling that never resolves.
Energy system development. A rider focusing on sprint work shows gold-dominant strips. A rider building threshold shows deep plum developing at the base. Development across the full spectrum shows vivid color from top to bottom.
Peak form. The sharpest, most brilliant strips in the entire sequence are peak form: high fitness, low fatigue, full energy system engagement. You locate your best days by finding the brightest, crispest threads in the weave.
How PTA drives the color
Loom's color mapping is driven by the Power Threshold Array. PTA detects seven bioenergetic transitions, each corresponding to a shift in energy system dominance. From the neuromuscular ceiling of a sprint (PT-N) through the glycolytic burn of sustained anaerobic effort (PT-G, PT-X) to the oxidative demands of threshold riding (PT-O, PT-V, PT-T), each threshold marks where physiology actually shifts for that individual.
Each ride is mapped against these seven thresholds, producing a physiological profile rendered as color. A criterium produces a strip dominated by gold and amber at the top (repeated sprints, neuromuscular and glycolytic demands) with threshold barely present. A tempo ride shows deep plum filling the base with the upper register quiet. A road race that ends in a sprint shows the full spectrum. The geometric pattern of the seven thresholds is the fingerprint of that ride.
PT Seat™
Each threshold has a PT Seat™: its position defined by two coordinates. Threshold Power (watts) and Threshold Offset (the duration at which the transition occurs for that individual). Seven seats produce fourteen independent development signals, because each seat can move in either dimension independently.
This is the distinction between scalar and vector analysis. Every existing platform performs scalar analysis: a single power value at a predetermined duration. PT Seat™ resolves a two-dimensional coordinate. Power can shift, position can shift, or both can move together. Each pattern is a distinct physiological signal that scalar analysis cannot produce.
The four quadrants
When a PT Seat™ is plotted relative to a baseline measurement, the axes define four quadrants of development:
Upper right is unambiguous development: more power, later offset. The energy system got stronger and more enduring. Lower left is regression in both dimensions. Upper left means the system is more powerful but compressed in time. Lower right means endurance without power gains: the system sustains output further but doesn't produce more force.
The Racing Effect — population-level evidence that competitive racing develops the full physiological spectrum.
The Shape of the Heat — the design story behind Loom, from warming stripes to Tufte's principles.