Bike Training and Power

Strain gauges measure force (torque) and the meter combines it with rotational speed to give watts. Watts are a rate of mechanical work, nothing more.

Source: General cycling coaching reference

The same 220 W is the same 220 W into a headwind, up a climb or on a flat road, while the resulting speed can vary hugely.

Source: General cycling coaching reference

Power is what you are doing right now; heart rate is your body's delayed reaction to it. The lag is physiological, not a sensor limitation.

Source: General cycling coaching reference

Heart rate typically needs a minute or more to reach a steady value for a given workload, so a short interval can be over before it catches up.

Source: General cycling coaching reference

Over long efforts, rising body temperature and falling blood volume push heart rate up even when the mechanical work is identical.

Source: General cycling coaching reference

It is a model that weights hard surges more heavily than easy sections, because they cost you disproportionately. It is a useful estimate, not a measured physiological value.

Source: General cycling coaching reference

The more variable the ride, the bigger the gap. On a perfectly steady effort the two numbers converge.

Source: General cycling coaching reference

A power meter reports external output only. Whether 250 W is comfortable or ruinous today comes from heart rate, perceived effort and how you feel.

Source: General cycling coaching reference

Strain gauges have a baseline that shifts, so a quick zero before riding keeps the readings trustworthy, especially on cold or hot days.

Source: General cycling coaching reference

A few per cent is lost through the chain and gears, so a hub reads lower than a crank. Compare yourself against your own meter, not someone else's.

Source: General cycling coaching reference

It is a practical anchor for setting training intensities. The actual time a rider can hold FTP varies a lot between individuals.

Source: General cycling coaching reference

The 95% figure is an average correction, not a law. For an individual rider the true adjustment can be meaningfully bigger or smaller.

Source: General cycling coaching reference

Riders with a big anaerobic contribution tend to score a flatteringly high ramp FTP, which is one reason ramp and 20-minute results disagree.

Source: General cycling coaching reference

A physiological threshold is measured in a lab with repeated steady-state trials. Field protocols are practical proxies, and how well they agree is genuinely debated.

Source: General cycling coaching reference

Zone edges are convenient labels drawn onto a continuous response. Being a few watts out does not ruin a session.

Source: General cycling coaching reference

Testing costs a hard session and the fatigue that follows, so testing weekly disrupts more training than it informs.

Source: General cycling coaching reference

FTP is one point on a curve. Durability, repeatability and sprint power all sit outside it and shape how a rider actually races.

Source: General cycling coaching reference

On the flat, raw watts largely decide your speed; on a sustained climb, watts per kilogram does.

Source: General cycling coaching reference

If your threshold has risen, yesterday's threshold watts now sit below it, so the prescribed intensity no longer matches the intent.

Source: General cycling coaching reference

Because every protocol is an estimate with its own bias, consistency of method matters more than which method you chose.

Source: General cycling coaching reference

Ten minutes of work at an intensity you could only hold for four minutes straight is only possible if it is divided up.

Source: General cycling coaching reference

The work-to-rest ratio is a dial in its own right: same watts with less rest is a meaningfully bigger session.

Source: General cycling coaching reference

Very short, very hard reps push you towards your aerobic ceiling, which longer threshold work does not reach.

Source: General cycling coaching reference

Long reps near threshold target exactly the quality a triathlon bike leg demands: sustained, steady output.

Source: General cycling coaching reference

Sessions are usually judged on whether the last rep held target. Consistently failing it means the session was set too hard.

Source: General cycling coaching reference

Total quality work is higher when reps are even. A blown first rep costs you more on the remaining ones than it gained.

Source: General cycling coaching reference

Easy pedalling keeps blood flowing through working muscle and keeps you warm, without adding meaningful load.

Source: General cycling coaching reference

Once you can no longer reach the intensity the session was built around, extra reps add fatigue without adding the intended stimulus.

Source: General cycling coaching reference

Growing the volume of work at a given intensity is a more durable progression than chasing a higher number every week.

Source: General cycling coaching reference

The 'under' section is a working recovery, not a real one, which is what makes the format demanding and race-like.

Source: General cycling coaching reference

The trainer's real advantage is uninterrupted control of intensity and duration, which makes interval sessions far easier to execute properly.

Source: General cycling coaching reference

The gap is commonly reported but not universal, and good cooling narrows it. Motivation, position and differences between power meters also contribute, so treat it as a tendency.

Source: General cycling coaching reference

Without the airflow you get outdoors, body temperature climbs quickly, pushing heart rate up and power down.

Source: General cycling coaching reference

The trainer takes responsibility for the number, so the target is met as long as you keep pedalling. This holds within a workable gear and cadence range, not at the extremes.

Source: General cycling coaching reference

Self-pacing is a skill you need on race day. It is also easy to get caught in a low-cadence spiral, where dropping cadence makes the resistance feel heavier still.

Source: General cycling coaching reference

Slope mode behaves more like the road, which makes it the better choice when you want to rehearse pacing yourself.

Source: General cycling coaching reference

Virtual racing generates genuine training stress in a shape you did not choose, so it needs a slot in the week like any other hard day.

Source: General cycling coaching reference

The trainer builds the engine well but removes everything about controlling a bike on real roads, so outdoor riding still has to happen.

Source: General cycling coaching reference

An outdoor ride is full of small free moments; indoors there are none, so indoor sessions are usually planned shorter for the same load.

Source: General cycling coaching reference

The size of any indoor-outdoor difference is individual and depends heavily on cooling, so there is no universal conversion to apply.

Source: General cycling coaching reference

The long ride develops aerobic endurance and resistance to fatigue over hours, which is what a triathlon bike leg demands. Peak power and VO2max respond mainly to shorter, harder work.

Source: General cycling coaching reference

The long ride is scaled to what the race actually asks of you. Even long-course athletes rarely ride the full race distance in training, because the recovery cost outweighs the gain.

Source: General cycling coaching reference

Durability describes the retention of performance late in a long ride, when fresh-state numbers no longer apply. It is one of the main qualities the long ride trains.

Source: General cycling coaching reference

A long ride needs time for its adaptation to land, and that window is a guideline rather than a fixed rule, varying with the athlete and the race distance. Move it closer and you buy fatigue rather than fitness.

Source: General endurance coaching reference

Two shorter rides still build aerobic volume and are far better than an abandoned session. What they cannot reproduce is hour four, which is where durability and race-day fuelling are actually tested.

Source: General endurance coaching reference

A long ride raced flat out is expensive to recover from, and the damage shows up as missed or degraded sessions later in the week rather than in the ride itself.

Source: General cycling coaching reference

Race-effort blocks placed late in a long ride simulate the specific demand of holding pace under accumulated fatigue, which riding fresh cannot reproduce.

Source: General cycling coaching reference

Terrain shapes how the effort is distributed, so matching it to the race course rehearses the actual pattern of work you will face.

Source: General cycling coaching reference

Sheltered riding is surge-and-coast and lower in average demand, whereas a triathlon bike leg is a sustained solo effort. Company is fine, but some long rides should mirror the race.

Source: General cycling coaching reference

Normal long rides leave short-term fatigue, appetite and some cardiac drift. The warning sign is a recovery cost that keeps eating the rest of the training week.

Source: General cycling coaching reference

Cadence work broadens the range of pedalling rates you can hold efficiently. It is a coordination and comfort adaptation, not a substitute for aerobic or strength training.

Source: General cycling coaching reference

Studies repeatedly find freely chosen cadence sits above the metabolically optimal rate, probably to lower muscular force per stroke. That mismatch alone is not a reason to force a change.

Source: General cycling coaching reference

Spinning above your usual rate is a coordination stimulus: it trains you to stay smooth and controlled when each stroke is shorter and force per stroke is lower.

Source: General cycling coaching reference

Riding at a low cadence for a given power raises the force needed in each stroke, which is the intended stimulus. It does not lower per-stroke force or change your natural cadence.

Source: General cycling coaching reference

Muscle activation during one-legged pedalling does not match the two-legged pattern, and evidence that the drill improves normal pedalling is weak.

Source: General cycling coaching reference

Skilled cyclists still unweight rather than truly pull up, and consciously pulling up has generally worsened rather than improved measured efficiency.

Source: General cycling coaching reference

Cadence naturally drops as resistance rises on a climb. There is no single correct climbing cadence, so ride near the rate that feels sustainable for you.

Source: General cycling coaching reference

Research on cadence in the final part of the bike shows an effect on the following run, but the direction is not the same for every athlete, so it is worth testing in training.

Source: General cycling coaching reference

The point of the drill, high force per stroke, is also its risk: joint loading at the knee rises, so these sessions are built up slowly and dropped at the first sign of pain.

Source: General cycling coaching reference

Technique work needs quality, so drills go in short bouts when you are fresh. Practising a pattern under heavy fatigue mostly reinforces poor form.

Source: General cycling coaching reference

A fit adapts the bike to the rider, balancing sustainable comfort, power output and injury risk. A position that cannot be held for the whole race is not a good fit.

Source: General cycling coaching reference

Only three parts of the body touch the bike: feet, seat and hands. Every fit adjustment ultimately works through one of those interfaces.

Source: General cycling coaching reference

An excessive saddle height forces the rider to reach for the pedal at the bottom of the stroke, producing hip rock, posterior knee strain and saddle friction.

Source: General cycling coaching reference

A low saddle keeps the knee more flexed and increases compressive load at the front of the joint. Hip rock and posterior knee strain point the other way, to a saddle set too high.

Source: General cycling coaching reference

Reach and drop describe how far forward and how far down the front end sits relative to the saddle, and together they set how stretched and low the rider is.

Source: General cycling coaching reference

Dropping the front end alone would close the hip angle severely, so a TT fit rotates the whole rider forward by moving the saddle forward as well.

Source: General cycling coaching reference

A fit describes a relationship between one rider and one bike, so it should be revisited whenever either side of that relationship changes meaningfully.

Source: General cycling coaching reference

Drag falls as the rider gets lower and more compact, but the same change restricts the hip and adds strain, so the useful position is the fastest one you can actually hold.

Source: General cycling coaching reference

Fit problems tend to be localised, reproducible and tied to time in position. Diffuse fatigue and breathlessness are training responses, not fit signals.

Source: General cycling coaching reference

The cleat defines the foot-pedal interface, so fore-aft and rotational position influence how the knee tracks and how far the saddle effectively sits from the pedal.

Source: General cycling coaching reference

IF expresses how hard a ride was relative to your own threshold: normalized power divided by FTP. An IF of 0.75 means the ride averaged, in effect, 75% of threshold.

Source: General cycling coaching reference

On a variable ride normalized power exceeds average power, so VI climbs above 1.00 with surging. On a very steady ride the two converge and VI sits at or just under 1.00.

Source: General cycling coaching reference

Perceived effort underreads early in the bike leg, so the same watts feel cheap. Treating the planned number as a ceiling for the first ten minutes protects the rest of the race.

Source: General triathlon coaching reference

The metabolic cost of riding above threshold rises steeply, while the time saved is minimal. Average power can look correct while the surges have already emptied you.

Source: General cycling coaching reference

A small, bounded increase on climbs is efficient because you spend longer there; large spikes are not. The cap is what keeps the climb from becoming a surge.

Source: General cycling coaching reference

Sustainable intensity declines with duration, which is why longer races carry lower power targets. Exact targets vary by athlete, so use the trend rather than a fixed number.

Source: General triathlon coaching reference

The plan is an estimate; the legs are the measurement. Riding a number your body is rejecting on the day usually turns a modest bike deficit into a failed run.

Source: General triathlon coaching reference

In heat, blood is diverted to the skin and core temperature climbs, so the same watts cost more. A modest downward adjustment protects both the bike and the run.

Source: General triathlon coaching reference

A stale or aspirational FTP produces a target you cannot hold. Raw twenty-minute power also overstates FTP and needs the standard downward adjustment before use.

Source: General cycling coaching reference

A late push buys seconds on the bike and can cost minutes on the run. Fatigue accumulated in the last quarter of the ride does not disappear at dismount.

Source: General triathlon coaching reference

Within a short session, structure is what converts time into adaptation. Defined intervals with defined recoveries give a clear stimulus that vague moderate riding does not.

Source: General cycling coaching reference

Middling riding costs real fatigue while delivering a weak stimulus, so it is the cheapest thing to lose. Stripping out all easy riding instead leaves a week you cannot absorb.

Source: General endurance coaching reference

Duration-specific adaptations and practical fuelling practice cannot be compressed into an hour. Top-end power, by contrast, responds well to short interval work.

Source: General triathlon coaching reference

Commutes add genuine aerobic time and should be counted as load, but stop-start traffic makes them unreliable for precise interval work.

Source: General cycling coaching reference

Intensity maintains and can improve threshold and aerobic power efficiently, but the ability to keep producing power hours into a race tracks with accumulated duration.

Source: General endurance training literature

Outdoors, a surprising share of any ride is spent freewheeling or stopped. Indoors the pedals never stop, so the prescribed work actually gets done.

Source: General cycling coaching reference

Low-volume training supports strong fitness, but the later hours of a long race expose the durability that volume builds. Plan pacing and fuelling accordingly.

Source: General triathlon coaching reference

More frequent riding gives repeated adaptive signals and keeps you comfortable on the bike, while one longer ride preserves the duration stimulus.

Source: General cycling coaching reference

Preparation and cool-down eat into any short session, so plan the main set around what is left. The recoveries sit inside that main set rather than being extra.

Source: General cycling coaching reference

Sprint-interval studies show real gains, with the biggest effects in untrained or recreational subjects. Trained endurance athletes benefit too, but as an addition to a volume base rather than a substitute for it.

Source: Exercise physiology literature on sprint interval training

Speed is an output of fitness plus environment. Two rides at identical fitness can differ by several km/h purely through wind and terrain.

Source: General cycling coaching reference

The shape of the curve, not just one point on it, shows which durations you have actually been training. A rise confined to short efforts points to a build that has been short on sustained work, which is what a triathlon bike leg demands.

Source: General endurance coaching reference

Power for a set duration is the cleanest fitness signal available. Maximum heart rate does not rise with training, and loop times are confounded by conditions.

Source: General cycling coaching reference

Gravity scales with mass, so weight matters on climbs. On the flat, absolute power against aerodynamic drag is what sets speed, and heavier riders descend faster.

Source: Cycling physics and coaching reference

Day-to-day performance varies substantially at unchanged fitness. Judging a training block on one bad Tuesday leads to unnecessary plan changes.

Source: General endurance coaching reference

Faster equipment produces a faster split at unchanged or even lower power, which also lowers heart rate. Only the power data disentangles the two.

Source: General cycling coaching reference

The decoupling of heart rate from power during long efforts shrinks as aerobic endurance improves, making it a useful season-scale marker.

Source: General endurance coaching reference

Ramp and long-effort protocols suit different rider profiles and routinely disagree. Compare like with like, or retest with the original protocol.

Source: General cycling coaching reference

Units differ by a few percent, which is the same size as a season's genuine gains. Without a cross-check, the switch itself looks like a fitness change.

Source: General cycling coaching reference

Durability is measured by holding the effort constant and moving it later in the ride. A benchmark ridden fresh says nothing about hour four.

Source: General endurance coaching reference