Cycling Training Glossary

Sweet Spot Training#

Also known as: SST

A training method, pioneered by FasCat Coaching founder Frank Overton, that concentrates riding in the sweet spot intensity zone of roughly 84 to 97 percent of FTP. It produces the greatest fitness gains for the least amount of fatigue, making it the most time-efficient way for cyclists to build aerobic power.

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Sweet Spot#

The cycling intensity zone spanning roughly 84 to 97 percent of Functional Threshold Power (FTP) — harder than tempo but below threshold. Training in the sweet spot drives strong aerobic adaptations while keeping fatigue low enough to train frequently.

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Sweet Spot Base#

FasCat's signature base-training approach that replaces long, low-intensity junk miles with focused sweet spot intervals. It builds a strong aerobic foundation in far less weekly training time than traditional high-volume base programs.

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FtFP#

Also known as: Follow the Plan

FasCat's signature mantra and sign-off: "Follow the F***ing Plan." It captures the core coaching philosophy that consistency beats heroics — the biggest fitness gains come from trusting your training plan and executing it day after day, not from chasing one-off hard efforts.

FTP (Functional Threshold Power)#

Also known as: Functional Threshold Power

The highest average power, in watts, that a cyclist can sustain for about an hour. FTP anchors every power-based training zone and is the single most important number for prescribing and tracking cycling fitness.

Power Curve#

Also known as: power-duration curve

A chart of a rider's best power output across every duration, from a few seconds to several hours. Its shape reveals a cyclist's strengths and phenotype — sprinter, pursuiter, or all-rounder — and is used to set individualized training targets.

Critical Power#

Also known as: CP

The highest power a cyclist can sustain aerobically for a long time without continuously fatiguing — mathematically, the asymptote of the power-duration curve. It is closely related to, and often used alongside, FTP.

W' (W-prime)#

Also known as: W prime, anaerobic work capacity

A rider's finite store of energy available for efforts above Critical Power, measured in kilojoules. Once depleted by hard accelerations or climbs, it must be recharged by riding below Critical Power.

xPower#

A FasCat metric that gives a smarter average of a cyclist's power output, accounting for short, high-intensity surges to reflect true physiological effort. Designed for highly variable riding, xPower paints a more accurate picture of sustainable power than Normalized Power, which can overestimate what a rider can actually hold.

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Threshold#

Also known as: lactate threshold

The exercise intensity at FTP, where lactate begins to accumulate faster than the body can clear it. Threshold intervals — efforts at or near 100 percent of FTP — raise the power a cyclist can hold for long durations.

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VO2 Max#

Also known as: VO2max

The maximum rate at which the body can consume oxygen during intense exercise. As a training zone, VO2 max intervals are very hard efforts, typically 3 to 8 minutes long, that raise a cyclist's aerobic ceiling.

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Anaerobic Capacity#

The ability to produce very high power for short, intense efforts of roughly 30 seconds to 2 minutes using energy systems that do not require oxygen. It powers attacks, sprints, and bridging gaps.

Tempo#

A moderate endurance intensity just below the sweet spot, roughly 76 to 90 percent of FTP. Tempo riding builds aerobic endurance and serves as a stepping stone toward sweet spot work.

Zone 2 (Endurance)#

Also known as: endurance pace, base miles

Aerobic endurance riding at a comfortable, conversational intensity of roughly 56 to 75 percent of FTP. Zone 2 builds the aerobic base — mitochondria, capillaries, and fat metabolism — that underpins all higher-intensity fitness.

Periodization#

The practice of organizing training into progressive phases — building a broad aerobic base first, then layering in intensity and race-specific work — so an athlete peaks for their most important events.

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Interval#

A repeated, structured effort at a prescribed intensity and duration, separated by recovery. Intervals concentrate training stress into specific energy systems to target a desired adaptation.

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Taper#

A planned reduction in training volume in the days before a key event that sheds accumulated fatigue while preserving fitness, so the athlete arrives fresh and at peak form on race day.

Optimize Recovery Score#

Also known as: Optimization Score, Optimize Score

The daily score at the heart of FasCat's CoachCat (Optimize) app that balances your training against your recovery. Calculated each morning from your Optimized Training Stress (OTS), sleep, HRV, and training load, it tells you whether to rest, train, or push harder that day.

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Level#

CoachCat's simple measure of how much you've been training lately, expressed as one clear number. It is a rolling six-week (42-day) weighted average of your daily Optimized Training Stress (OTS), so it rises as you ride more and eases as you recover. A rising Level during a build phase often means your FTP is climbing too.

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OTS (Optimized Training Stress)#

Also known as: Optimized Training Stress

FasCat's power-based measure of the true physiological cost of a ride. Unlike traditional training-load metrics, OTS accounts for fatigue that accumulates through a ride, carbohydrate fueling (or underfueling), and coasting time — dynamically adjusting for how threshold power (Critical Power / FTP) drops over long efforts.

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