Lesson 13 · What factors influence movement and performance?
Four letters, four decisions, and no way to hide a vague one
Everything so far has been analysis. This lesson is the one where you have to produce something: a written program that another person could pick up and carry out without asking you a single question. The FITT principle is the framework that makes that possible, and its real value is not that it helps you remember four words. It is that it exposes vagueness. "Do some interval training twice a week" survives conversation and dies the moment you try to write it as frequency, intensity, time and type — because three of the four turn out to be missing, and the one you have is the one that matters least.
Here is a training program, written out in full, exactly as it was handed to a 16 year old who wanted to improve their 5 kilometre time.
Everyone can see it is inadequate. The useful exercise is being precise about which decisions it failed to make. Write down every question the athlete would have to ask before they could do Monday's session — and be exhaustive, because the number of them is the point. Then a harder one: the program does contain one genuinely useful instruction. Identify which of the three sentences it is, and say why it is the one that survives.
- Define frequency, intensity, time and type, and say what decision each one settles.
- Set intensity in the three ways a program actually uses: percentage of maximum heart rate, percentage of one repetition maximum, and rating of perceived exertion.
- Explain why the four variables interact, so that raising one usually requires lowering another.
- Build progression into a program, and explain why only one variable should be advanced at a time.
- Explain what FITT does not cover, and why a program built on FITT alone can still be a bad program.
- Design a six-week aerobic or anaerobic program for a named athlete with a stated goal.
- Justify every one of the four decisions from the demands of the sport rather than from habit.
- Frequency — how often the training occurs, usually as sessions per week.
- Intensity — how hard each effort is, expressed relative to the athlete's own maximum.
- Time — the duration of each session, or of the work within it, including the work-to-rest structure.
- Type — the method used, chosen so that the system being targeted is the system actually stressed.
- Maximum heart rate — the highest rate the heart can reach; commonly estimated as 220 minus age, an estimate with a wide margin of error.
- Target heart rate zone — the band of heart rates corresponding to the intended training intensity.
- One repetition maximum, or 1RM — the heaviest load that can be lifted once with correct technique; the reference point for resistance intensity.
- Rating of perceived exertion, or RPE — a subjective intensity scale, typically 1 to 10, useful where no monitoring equipment exists.
- Progressive overload — the gradual increase in training demand required for adaptation to continue.
FITT is not a checklist to be ticked. It is the minimum set of decisions that must be made before a session can be carried out by someone who was not in the room when it was planned. That is the test to apply to any program, including your own: could a stranger execute Monday from what is written?
| Variable | The decision it settles | Aerobic example | Anaerobic example |
|---|---|---|---|
| Frequency | How often, and therefore how much recovery falls between sessions | 4 to 6 sessions per week; can be on consecutive days | 2 to 3 sessions per week, with at least 48 hours between heavy sessions |
| Intensity | Which energy system is stressed, and therefore which adaptation results | 70 to 85 per cent of maximum heart rate | Above 85 per cent of maximum heart rate, or 75 to 90 per cent of 1RM for resistance work |
| Time | How long the stress is applied, and the work-to-rest structure inside the session | 30 to 60 minutes of continuous work | Efforts of 10 to 120 seconds, with recovery from 1:3 to 1:20, total work often under 10 minutes |
| Type | Which method, and therefore how closely the training resembles the sport | Continuous, fartlek, long interval or circuit | Short interval, repeated sprint, plyometric or resistance |
Frequency and intensity are the two that most often contradict each other, and noticing that is what separates a designed program from a wished-for one. A program cannot be both very frequent and uniformly very intense, because the recovery required by high intensity is precisely what frequency removes. Almost every failed program a student writes fails here, and it fails silently — on paper it looks ambitious.
Quick check: A program prescribes "sprint training, five days a week, all-out efforts, 45 minutes per session". Its most serious flaw is that:
Intensity is the variable that decides which energy system is stressed, so it is the one that must be written as a number rather than as an adjective. There are three standard ways, and a program should use whichever one can actually be measured in the setting it will be used in.
1. Percentage of maximum heart rate. Estimate maximum heart rate as 220 minus age, then take the required percentage. For a 16 year old, maximum is estimated at 204, so a 70 to 85 per cent aerobic zone is roughly 143 to 173 beats per minute. This is the standard method for aerobic work and the reason heart rate monitors exist.
2. Percentage of one repetition maximum. For resistance work, intensity is a share of the heaviest load the athlete can lift once. Roughly: above 85 per cent of 1RM for 1 to 5 repetitions develops maximal strength; 70 to 85 per cent for 6 to 12 repetitions develops strength and muscle size; and below 70 per cent for 15 or more repetitions develops muscular endurance. The load and the repetition range are not two separate decisions — each implies the other.
3. Rating of perceived exertion. A 1 to 10 scale where 6 to 7 is roughly a moderate aerobic effort and 9 to 10 is maximal. It requires no equipment, works for any activity, and correlates well enough with heart rate to be useful. Its weakness is that it is subjective and that inexperienced athletes systematically under-rate hard efforts. For a school squad with no monitors, it is not a compromise; it is the correct choice, because a prescription that cannot be measured is not a prescription at all.
True or false: The formula 220 minus age gives an individual athlete's actual maximum heart rate, so a zone calculated from it needs no adjustment.
The four letters are written as a list, and that presentation is misleading. They are constraints on one another, and a designed program is a set of trades rather than four independent maxima.
- Intensity and time trade against each other directly. The harder the effort, the shorter it can be sustained — which is the same relationship the energy systems showed in Lessons 9 and 10, appearing again at the level of a session. A program prescribing maximal intensity for 40 continuous minutes has described something physiologically impossible, and that is a substantive error rather than an ambitious one.
- Intensity and frequency trade through recovery. Adaptation happens during recovery, not during the session. Removing recovery by raising frequency does not add adaptation; it subtracts it, and eventually produces the accumulating fatigue and raised injury risk of over-training.
- Type constrains the useful range of the other three. Plyometric work is high intensity and short by nature, so a plyometric session that is frequent and long has not been differentiated — it has been misunderstood.
- Time includes the work-to-rest structure, not just the clock. A 40 minute session containing eight minutes of work is a different physiological event from a 40 minute continuous run, and writing only "40 minutes" conceals which one you meant. This is the Lesson 12 point restated where it does the most damage.
Match each prescription to the FITT variable it specifies.
- Three sessions per week, with 48 hours between them
- 80 per cent of one repetition maximum
- Six efforts of 30 seconds, with 90 seconds recovery
- Fartlek running over undulating terrain
- Frequency
- Intensity
- Time
- Type
A program that prescribes the same four variables for six weeks produces adaptation for perhaps two of them and then stops. Once the body has adapted, the same load is no longer a stress, so progressive overload has to be written into the program rather than left to enthusiasm.
The rule that makes progression safe is simple and widely ignored: advance one variable at a time. Raise frequency, intensity and time together and the load rises steeply and unpredictably; more importantly, when something goes wrong you have no way of knowing which change caused it. Advancing one variable is both safer and diagnostic.
| Week | Frequency | Intensity | Time | What changed |
|---|---|---|---|---|
| 1–2 | 3 per week | 70% HRmax | 25 min | Baseline established |
| 3 | 4 per week | 70% HRmax | 25 min | Frequency only |
| 4 | 4 per week | 70% HRmax | 35 min | Time only |
| 5 | 3 per week | 70% HRmax | 25 min | Recovery week — load deliberately reduced |
| 6 | 4 per week | 80% HRmax | 35 min | Intensity only, from the week 4 baseline |
Week 5 is the row that marks out a considered program. A planned reduction in load lets accumulated fatigue clear so that the adaptation already stimulated can be expressed, and it is the point at which most student programs instead schedule their hardest week. A program that only ever goes up has confused the training with the adaptation.
A widely used starting guideline is to increase total weekly load by no more than about 10 per cent per week. It is a rule of thumb rather than a law, and like the heart rate formula it should be quoted with that qualification, but it is a sound default when nothing more specific is known about the athlete.
Two truths and a lie. Which statement is false?
FITT is a framework for making a program specifiable. It is not a framework for making it good, and a program can have all four variables written precisely and still be the wrong program. Four things it does not settle:
- Whether the type matches the demands of the sport. FITT requires you to name a type; it does not check that you named the right one. A netballer given a fully specified continuous running program has a complete FITT prescription aimed at the wrong quality. Specificity is what makes the type correct, and it sits outside the four letters.
- Whether the starting point suits the athlete. The same program is appropriate for one 16 year old and injurious for another. Individuality — the differentiation of Lesson 12 — is upstream of FITT.
- Safety and structure within the session. Warm-up, cool-down, technique standards, progression of complexity and the order of work within a session are all absent from FITT and all capable of ruining a program that satisfies it. Every session in a written program should begin with a warm-up and end with a cool-down, and a program that does not say so is incomplete.
- What happens when the six weeks end. Adaptations reverse when training stops, typically faster than they were gained. A program with no maintenance phase gives back what it produced.
Fill the gaps. Type one word or number in each box.
The four variables of the FITT principle are frequency, , time and type. Maximum heart rate is commonly estimated as minus the athlete's age. The gradual increase in training demand required for adaptation to continue is called progressive .
Text description
- Two parts, one above the other.
- Above, four labelled boxes linked by lines: frequency and time side by side at the top, intensity below them and type at the bottom. The time–intensity link is labelled trade-off and the frequency–intensity link is labelled recovery, showing that intensity trades against time, intensity trades against frequency through recovery, and type, joined to all three, constrains the useful range of the other three, with a note that raising one variable requires lowering another.
- Below, a six week progression chart with one horizontal bar per week, bar length showing training load: weeks one and two level as a baseline, week three raised by frequency alone, week four raised by time alone, week five deliberately dropped back as a recovery week, and week six raised by intensity alone to the highest load of the block.
Activities · put the method to work
This is the dot point itself, so do it properly. Choose one athlete: yourself, a teammate, or one of the two below. Design an aerobic or an anaerobic program — not both.
Mia, 16. Plays club netball, goal defence. Wants to stop fading in the fourth quarter. Trains with the team twice a week and has three free afternoons. No access to a gym; has a park and a phone.
Josh, 17. Sprinter, 100 and 200 metres. Wants to improve his last 30 metres. Has access to a track and a school gym, and is six weeks out from the first competition of the season.
Your submission must contain all six of the following. A program missing any one of them is not yet a program.
The goal, stated so it could be measured. "Get fitter" is not a goal. "Complete four quarters with less than a 10 per cent drop in sprint output" is.
The demands, in seconds. Effort durations and recovery durations for the sport or event, as in Lesson 10. Everything below must be traceable to these numbers.
All four FITT variables, written as numbers. Including the work-to-rest structure inside the session, and the intensity method you chose with its target zone calculated.
A six-week progression table with exactly one variable changing per step, and at least one week where the load comes down.
Warm-up and cool-down for every session, and any safety constraint that applies to your athlete.
A justification paragraph linking each of the four variables to the demands in step 2. This is the part that carries the marks in an exam, and it is the part most often left out.
Then apply the stranger test: hand it to someone who was not in the room and ask them to describe Monday's session back to you. Every question they have to ask is a decision you did not make.
Odd one out. Three of these are settled by the FITT principle. Which one is not?
Each program below has been written by someone who has heard of FITT. For each: name the specific fault, say which variable or which interaction is wrong, predict what will actually happen to the athlete, and write the one-line repair.
For a distance runner: "Six sessions a week, all at 90 per cent of maximum heart rate, 50 minutes each, continuous running. Add five minutes each week."
For a 400 metre runner: "Four sessions a week, 60 minutes of continuous running at 70 per cent of maximum heart rate. Progress by adding 10 minutes weekly."
For a school football squad: "Three sessions a week. Intervals. Work hard. 40 minutes."
For a 15 year old starting resistance training: "Five sessions a week, 95 per cent of one repetition maximum, three sets of one repetition, free weights. Add 5 kilograms every week."
One of these four is wrong in a way that is not about FITT at all — every variable is specified, and the program is still unsuitable. Identify which one, and name the thing FITT could never have caught.
Propose a six-week aerobic training program for a 16 year old club netballer who fades in the fourth quarter, using the FITT principle. Justify each decision.
Design means produce a plan, and in this dot point the plan must be specific enough to be carried out. But the sentence that follows it does the heavier lifting: justify. A fully specified program with no justification typically earns about half the marks, because the examiner cannot tell whether the numbers were reasoned or copied.
Plan: demands of the position in seconds first; goal stated measurably; then F, I, T and T each with its number and its reason in the same sentence; then the six-week progression with one variable per step and a recovery week; then what I traded.
Netball is intermittent over four 15 minute quarters. Individual efforts — a drive, a jump, a change of direction — last roughly two to five seconds and are supplied predominantly by the ATP-PCr system, separated by periods of jogging, walking and standing. Fading in the fourth quarter is therefore rarely a failure of maximal speed; it is a failure of recovery between efforts, and the aerobic system is what performs that recovery. An aerobic program is consequently the correct choice for this goal.
Frequency: three additional aerobic sessions per week alongside two team sessions, spaced so that no two hard days are consecutive, because aerobic work can be repeated frequently while the team sessions already impose high-intensity load. Intensity: 70 to 85 per cent of maximum heart rate, which for a 16 year old is approximately 143 to 173 beats per minute using 220 minus age, noting that this estimate carries an error of roughly ten beats and should be adjusted against her actual response. Time: 30 minutes, rising to 40, with one session per week structured as four blocks of four minutes at the top of the zone with two minutes easy between them. Type: continuous and fartlek running, with the interval session added from week 3, since fartlek's changes of pace resemble the intermittent demands of the game more closely than steady running does.
The goal is stated measurably: to reduce the drop in repeated-effort output between the first and fourth quarters, judged by her ability to complete the same defensive efforts late in the game without visible delay in arriving. The demands of the position set everything that follows. Netball is intermittent over four 15 minute quarters, with individual efforts of roughly two to five seconds supplied predominantly by the ATP-PCr system and separated by periods of jogging, walking and standing. Fading in the fourth quarter is therefore not primarily a loss of maximal speed but a loss of the capacity to recover between efforts, and since it is the aerobic system that resynthesises phosphocreatine and metabolises the by-products of glycolysis during those low-intensity periods, an aerobic program is the correct choice even though her individual efforts are anaerobic. Frequency is set at three aerobic sessions per week in addition to her two team sessions, arranged so that no two demanding days fall consecutively; aerobic work recovers quickly enough to be performed frequently, and the team sessions already supply the week's high-intensity load. Intensity is set at 70 to 85 per cent of maximum heart rate, approximately 143 to 173 beats per minute for a 16 year old using the estimate of 220 minus age; because that formula is a population average with an error of roughly ten beats per minute, the zone is a starting point to be adjusted against her measured response rather than a fixed prescription, and where no monitor is available a rating of perceived exertion of 6 to 7 out of 10 is the workable substitute. Time begins at 30 minutes per session and rises to 40, and from week 3 one of the three sessions is restructured as four blocks of four minutes at the top of the zone with two minutes of easy running between them, which raises the intensity at which her aerobic system can still predominate. Type is continuous and fartlek running, with fartlek preferred for at least one session because its changes of pace resemble the intermittent demands of a match more closely than steady running does, and the whole program is deliverable in a park with a phone, which is the equipment she actually has. Progression advances one variable at a time: weeks 1 and 2 establish a baseline of three sessions of 30 minutes at 70 per cent; week 3 introduces the interval session without changing frequency or duration; week 4 extends the continuous sessions to 40 minutes; week 5 deliberately reduces the load to two sessions of 30 minutes, because adaptation is expressed during recovery and a planned lighter week allows accumulated fatigue to clear; and week 6 raises intensity to 80 to 85 per cent from the week 4 baseline. Weekly load rises by no more than about 10 per cent at each step. Every session begins with a progressive warm-up including the movement patterns to be used and ends with a cool-down, since the program adds load to an athlete already training twice a week and the additional injury risk is real. The trade being made is explicit: the program adds aerobic volume and does not add anaerobic work, because her anaerobic qualities are already being loaded by team training and adding maximal work on top of five sessions a week would remove the recovery the program depends on.
A coach prescribes six sessions a week, all at 90 per cent of maximum heart rate, adding five minutes to each session weekly. Explain why this program will not produce the improvement intended.
Questions of this shape almost always contain several faults, and an answer that finds only the obvious one caps itself. Here there are three: frequency against intensity through recovery, intensity against time within each session, and a progression that advances a variable that is already too high.
Plan: name the interaction rule; fault 1, recovery; fault 2, the impossibility of 50 continuous minutes at 90 per cent; fault 3, the progression compounding it; then what the athlete will actually experience; then the repair.
Adaptation occurs during recovery rather than during the session, as the tissue repairs and rebuilds beyond its previous capacity. Six sessions a week at 90 per cent of maximum leaves no day on which that process can complete, so each session begins from an incompletely recovered state. The load accumulates rather than the adaptation, and performance falls while training volume rises.
90 per cent of maximum heart rate is above the intensity at which oxygen delivery can meet demand, so a substantial share of the energy must come from the glycolytic system, hydrogen ions accumulate and the effort cannot be sustained. Fifty continuous minutes at that intensity is not merely hard; it cannot be performed. In practice the athlete either drops the intensity, in which case the prescription is not what is happening, or stops early, in which case the program is not being followed.
This program fails for three separate reasons, and each of them is an interaction between FITT variables rather than a fault in any single one. First, frequency and intensity are incompatible. Adaptation occurs during recovery, when the tissue repairs and rebuilds beyond its previous capacity, and six sessions a week at 90 per cent of maximum heart rate leaves no day on which that process can complete. Each session therefore begins from an incompletely recovered state, so training load accumulates while adaptation does not, producing the rising fatigue, falling performance, disturbed sleep and raised injury risk characteristic of over-training — an athlete who trains more and performs worse. Second, intensity and time are incompatible within each session. At 90 per cent of maximum heart rate the athlete is working above the intensity at which oxygen delivery can meet demand, so a significant proportion of the energy must be supplied glycolytically, hydrogen ions accumulate and muscle pH falls. Fifty continuous minutes at that intensity cannot be performed, so in practice the athlete either reduces the intensity, meaning the prescription no longer describes what is happening, or abandons the session, meaning the program is not being followed; either way the coach no longer knows what training is being done. Third, the progression advances the wrong variable. Adding five minutes per week increases time when time is already limited by an intensity that is itself too high, so the single change compounds both existing faults instead of addressing either, and it does so in a way that makes the cause of any breakdown impossible to identify because the athlete was never on a sustainable baseline. The repair follows directly from the diagnosis. The great majority of the weekly volume should be performed at 70 to 85 per cent of maximum heart rate, where it can be sustained and repeated, with one or at most two higher-intensity sessions per week placed so that they are separated by at least 48 hours and preceded by an easier day. Progression should then advance one variable at a time from that baseline, with a planned reduction in load every third or fourth week so that the adaptation already stimulated can be expressed. The underlying principle the original program ignores is that the four FITT variables constrain one another, so raising one requires lowering another, and a program in which every variable rises together has not been designed at all.
Multiple choice · 5 questions
MC 1. In the FITT principle, the variable that most directly determines which energy system is stressed is:
- A. frequency
- B. intensity
- C. time
- D. type
MC 2. Using the common estimate, the aerobic training zone of 70 to 85 per cent of maximum heart rate for a 16 year old is approximately:
- A. 120 to 150 beats per minute
- B. 143 to 173 beats per minute
- C. 175 to 200 beats per minute
- D. 100 to 130 beats per minute
MC 3. Resistance training at above 85 per cent of one repetition maximum for 1 to 5 repetitions primarily develops:
- A. muscular endurance
- B. aerobic capacity
- C. flexibility
- D. maximal strength
MC 4. A program should advance only one FITT variable at a time principally because:
- A. changing more than one is prohibited by the principle of specificity
- B. the load rises more predictably and the cause of any problem can be identified
- C. the athlete would otherwise adapt too quickly to continue improving
- D. the other three variables cannot be measured accurately
MC 5. A planned reduction in training load in week 5 of a six-week program exists in order to:
- A. give the athlete a break from a program they are finding boring
- B. allow accumulated fatigue to clear so the adaptation already stimulated can be expressed
- C. reduce the total cost of the program in training time
- D. reverse the adaptations of the first four weeks before starting again
Short answer · exam style
SA 1. Remember Band 3 Outline the four components of the FITT principle, giving one example of how each would be written in an aerobic training program. (4 marks)
SA 2. Understand Band 5 Explain why raising one FITT variable usually requires lowering another. Use two specific examples. (5 marks)
SA 3. Apply Band 6 Design a six-week anaerobic training program for a 17 year old sprinter, using the FITT principle, and justify each decision from the demands of the event. (6 marks)
📖 Comprehensive answers (click to reveal)
Multiple choice: 1 → B. 2 → B. 3 → D. 4 → B. 5 → B.
Activity 1 guidance: The two scenarios are chosen because they pull in opposite directions and both resist the obvious answer. Mia's goal looks anaerobic and is served by an aerobic program, because fourth-quarter fade is a recovery failure and the aerobic system performs the recovery; students who prescribe more sprint work have read the symptom and not the mechanism. Josh's goal — the last 30 metres of a 200 — is genuinely anaerobic, and the trap there is the opposite one: six weeks out from competition is not the time for a high-volume block, so the program should be low in volume, high in quality, with long recoveries preserving the speed of each effort, and should taper. On step 3, the commonest omission is the work-to-rest structure, which is the variable that decides whether the session trains speed or lactate tolerance; a session written as "40 minutes of intervals" is not specified. On step 5, warm-up and cool-down are worth insisting on because they are absent from FITT and therefore absent from most student programs. The stranger test is the part worth doing literally: in practice it finds two or three unmade decisions in almost every first draft, and the most common is the intensity of the recovery periods, which students leave unstated.
Activity 2 guidance: Program 1 has the frequency-intensity conflict and the intensity-time impossibility together, and its progression advances time when time is already the constrained variable. Program 2 has every variable specified and legal, and is nonetheless wrong — this is the one whose fault FITT could never catch. A 400 metre race lasts roughly 45 to 60 seconds and depends heavily on the glycolytic system and on tolerance of its by-products, so a program consisting entirely of continuous running at 70 per cent trains the wrong quality; the fault is specificity, which lies outside the four letters. Program 3 fails the stranger test at three of the four variables: "intervals" is not a type, "work hard" is not an intensity, and "40 minutes" conceals the work-to-rest structure that decides what the session actually is. Program 4 is the safety case: 95 per cent of one repetition maximum with free weights, five times a week, for a novice 15 year old, is a program whose loading is beyond the athlete's training age and whose frequency leaves no recovery, and the weekly 5 kilogram increase is arithmetic rather than progression. Note that all four also share one omission — none mentions a warm-up.
SA 1 (4 marks): One mark per component correctly defined with a usable aerobic example. Frequency — how often, for example four sessions per week [1]. Intensity — how hard, expressed relative to the athlete's maximum, for example 70 to 85 per cent of maximum heart rate [1]. Time — the duration of the session and the work-to-rest structure within it, for example 30 minutes continuous [1]. Type — the method used, for example continuous or fartlek running [1]. A component named without an example, or an example given as an adjective rather than a number, does not earn the mark.
SA 2 (5 marks): States the principle that the four variables constrain one another, so a program is a set of trades rather than four independent maxima [1]. Example 1, intensity against time, with the physiology — above roughly 85 per cent of maximum, oxygen delivery cannot meet demand, so the glycolytic system contributes, hydrogen ions accumulate and the effort cannot be sustained; the harder the work, the shorter it must be [1]. Example 2, intensity against frequency, through recovery — adaptation occurs during recovery, so high-intensity sessions require 48 hours or more between them and cannot be performed daily [1]. The consequence of raising both together — load accumulates while adaptation does not, producing declining performance, rising injury risk and the over-training state [1]. The programming implication — when raising one variable, identify the one being lowered to pay for it, and advance only one at a time so the cause of any problem remains identifiable [1].
SA 3 (6 marks): Measurable goal stated [1]. Demands of the event given in seconds and mapped onto the energy systems — a 100 metre race lasts roughly 10 to 12 seconds and is supplied predominantly by ATP-PCr, a 200 roughly 21 to 25 seconds with a rising glycolytic contribution, which is why the last 30 metres is where the deceleration appears [1]. Frequency justified — two to three quality sessions per week with at least 48 hours between them, because maximal work requires substantial recovery [1]. Intensity and time given as numbers including the work-to-rest structure — maximal efforts of 20 to 60 metres with three to five minutes between repetitions, since long recoveries allow near-complete phosphocreatine restoration and preserve the quality of every effort [1]. Type justified — short intervals and repeated sprints, supported by plyometric and resistance work for power, all specific to the movement pattern [1]. Six-week progression advancing one variable at a time, with a recovery week, plus warm-up, cool-down and the recognition that being six weeks from competition means low volume and high quality rather than a heavy block [1]. A program that prescribes short recoveries between maximal sprints has trained lactate tolerance instead of speed and cannot earn the intensity-and-time mark, because it contradicts the goal it stated.
FITT is the minimum set of decisions that makes a program executable by someone who was not in the room. Frequency settles how often and therefore how much recovery falls between sessions. Intensity settles which energy system is stressed and therefore which adaptation results. Time settles how long the stress is applied, and it includes the work-to-rest structure, which is the part most often left out. Type settles the method. Apply the stranger test to anything you write: every question they have to ask is a decision you did not make.
Intensity has to be a number, and there are three legitimate ways to get one. Percentage of maximum heart rate, estimated as 220 minus age — roughly 143 to 173 beats per minute for the 70 to 85 per cent zone at 16, and worth quoting with the reminder that the formula carries about ten beats of error. Percentage of one repetition maximum, where the load and the repetition range imply each other. And rating of perceived exertion, which is the right choice rather than a compromise when no equipment exists, because an unmeasurable prescription is not a prescription.
The four variables constrain one another. Intensity trades against time directly, and against frequency through recovery; type limits the useful range of all three. So when you raise one, name the one you lowered to pay for it. A program in which everything rises at once looks ambitious and is simply unplanned — and its failure will be silent until the athlete breaks down.
Progression belongs in the program, one variable at a time, with a week that goes down. Advancing a single variable is both safer and diagnostic. A planned lighter week is not lost time; it is when the adaptation you already stimulated gets expressed. And remember the four things FITT cannot see: whether the type is specific to the sport, whether the starting point suits the athlete, whether the session is safely structured with a warm-up and cool-down, and what happens when the block ends.
Lesson 14 turns to what happens the moment training starts. The immediate physiological responses — heart rate, ventilation rate, stroke volume, cardiac output and lactate levels — are what you would measure to check that a program is doing what it was designed to do.
Mark lesson as complete
Tick when you've finished the practice and review.