51 guides on sport. Showing the 48 most recent.
Pace, load and the measurements training is planned from. Each figure here names the published equation that produced it, with its author and year, so an estimate is never mistaken for a measurement.
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Best 8 of your last 20 score differentials, averaged, and no 0.96 multiplier — that disappeared in 2020. Here is the full chain from a gross 92 to a Course Handicap of 17, with the numbers worked out.
Aisha Karim · 7 min read
A 176 lb man benching 220 lb is intermediate, not strong. Here are the usual bodyweight multiples for bench, squat and deadlift, and why the labels mislead more often than they help.
Aisha Karim · 4 min read
Run as far as you can in twelve minutes, then read the distance against your age and sex. The same number also converts straight into an estimated VO2 max — here is the table and the formula.
Aisha Karim · 5 min read
Use the Riegel formula to predict your half marathon time from a recent 5K or 10K, then turn that estimate into a realistic race-day pace with a smart pacing plan.
Aisha Karim · 5 min read
How many calories does swimming burn? Learn the MET-based formula, typical MET values for freestyle, breaststroke, backstroke, and butterfly, and how weight and effort change the total.
Aisha Karim · 4 min read
The 10% rule says to raise your weekly running mileage by no more than 10% at a time. Learn why it works, when to break it, and how to plan safe progression.
Aisha Karim · 4 min read
Use the Wilks coefficient to compare powerlifting totals fairly across bodyweights, so a lighter and heavier lifter can be ranked.
Aisha Karim · 4 min read
What VO2max measures, how it ranges by age and sex in ml/kg/min, and the training that raises it.
Aisha Karim · 3 min read
How to convert between running pace in minutes per mile and speed in miles per hour, with the exact formulas.
Aisha Karim · 4 min read
Turn your FTP into the seven Coggan training zones, each a percentage of threshold power, to guide every ride.
Aisha Karim · 4 min read
Set a 300–500 kcal daily deficit to lose fat at a safe, sustainable rate while keeping muscle and training quality.
Aisha Karim · 4 min read
To build muscle, aim for about 1.6 to 2.2 grams of protein per kilogram of body weight daily. Learn how to hit that target, spread it across meals, and time it around training.
Aisha Karim · 3 min read
FTP is the highest power in watts you can hold for about an hour. Learn how to test it, why watts per kilogram matters, and how it guides training zones.
Aisha Karim · 3 min read
Turn a marathon goal time into a pace per mile and hold even splits. Learn the math, the pacing strategy, and how to check your target is realistic.
Aisha Karim · 3 min read
MET values let you estimate calories burned for any activity. Learn the formula — MET × 3.5 × kg ÷ 200 × minutes — and typical MET values for common exercises.
Aisha Karim · 3 min read
10,000 steps works out to roughly 4 to 5 miles for most people. Learn how stride length turns steps into distance, and how many calories the walk burns.
Aisha Karim · 3 min read
There is a standard behind two-person, and its berth is 24 inches wide. Divide real floor plans by their occupants, compare the result with a sleeping pad, then compute how much of a quoted peak height actually exists: in a straight-sided A-frame, sitting height covers 18 per cent of the floor width.
Aisha Karim · 14 min read
The numbers on a sleeping bag come from ISO 23537-1, which publishes four figures and lets retailers print one. The standard measures a heated manikin's heat loss — so it measures insulation, and its own test mat is R 4.8. Put the same bag on an R 1.5 pad and the heat leaving through your back more than triples.
Aisha Karim · 14 min read
A published walking-energetics equation turns body mass, pack weight, speed and terrain into a daily calorie figure. But calories are not what you carry — mass is. Work the arithmetic and the planning number stops being calories per day and becomes calories per ounce.
Aisha Karim · 14 min read
Every zone scheme is a set of percentages of some anchor, and the anchor is the whole argument. One runner, three published schemes: the ceiling of easy aerobic work lands at 131, 141 or 150 bpm. And if the anchor is 220 minus age, a two-standard-deviation error moves one boundary by 30 bpm.
Aisha Karim · 17 min read
Percentage-based training scales every lift to your one-rep max. Learn the strength and hypertrophy zones and how to set your working weights.
Aisha Karim · 4 min read
Watts per kilogram is the number that decides who climbs fastest. Learn how W/kg works, what it means for FTP and how to improve it.
Aisha Karim · 3 min read
Learn how to estimate your maximum heart rate, use the Karvonen formula and train in the right zones so every session hits its intended intensity.
Aisha Karim · 3 min read
Batting average is hits divided by at-bats. Learn how to calculate it, why a .300 hitter is excellent and what counts as an at-bat in baseball.
Aisha Karim · 4 min read
Walking time is distance divided by speed. Learn the average walking speed of about 3 mph and how to estimate the time for any distance.
Aisha Karim · 3 min read
50/11 means nothing until you attach a wheel. Gear inches and metres of development, derived and converted, a full table for a real 12-speed drivetrain, and why the gear step between two sprockets decides whether you can hold a cadence.
Aisha Karim · 13 min read
xG is the fitted probability that a shot with a given set of features becomes a goal — a model output, not an observation. A worked match, the binomial arithmetic that says one game is far too few shots, and the limits nobody quotes.
Aisha Karim · 13 min read
French, YDS, UIAA, V-scale and Font are ordinal scales with no underlying unit. A conversion table is a negotiated alignment between climbing communities — and published tables disagree by half a grade at the top and by four letter-grades at the bottom of the boulder scales.
Aisha Karim · 15 min read
Speed equals distance divided by time. Learn how to compute your running speed in mph, tell speed apart from pace and convert between the two.
Aisha Karim · 4 min read
Use a recent race result and the Riegel formula to predict your finish time at a longer distance — from a 5K to a 10K or half marathon.
Aisha Karim · 4 min read
A strike scores ten plus your next two balls, a spare ten plus your next one. That bonus chain is the entire game — it is why a perfect game is 300 and why alternating strikes and spares scores 200, not the 250 almost everyone guesses.
Aisha Karim · 11 min read
Running pace is time per kilometre or mile. Here's how to work it out from any run, convert between units, and use it to pace a race without blowing up.
Aisha Karim · 3 min read
ERA measures what happened, FIP measures only what the pitcher controls without his fielders, WHIP measures traffic allowed. Two pitchers can swap places entirely between them — and the gap between ERA and FIP is a forecast, not a verdict.
Aisha Karim · 10 min read
OPS adds two fractions with different denominators, which as arithmetic is indefensible. It survives because it tracks run scoring far better than batting average and costs nothing to compute — but it underpays on-base ability, and OPS+ does not fix that.
Aisha Karim · 10 min read
Field goal percentage counts a three-pointer and a layup as the same event and ignores free throws entirely. eFG% fixes the first problem, TS% fixes both — and the ranking of three players changes at every step.
Aisha Karim · 10 min read
Turning jump height into take-off velocity is exact physics. Turning it into watts is a regression fitted on somebody else's athletes — and the three common formulas disagree by thousands of watts on the same jump.
Aisha Karim · 13 min read
BMI weighs you and divides by your height squared. It cannot tell muscle from fat, which is why lean athletes get classed overweight. FFMI removes the fat first — and inherits every error in the body-fat estimate it is built on.
Aisha Karim · 13 min read
Epley, Brzycki, Lombardi, O'Conner and Wathan are five curves through the same data. They agree within a few pounds at low reps and disagree by a quarter at fifteen — which is exactly how you know when an estimate is worth having.
Aisha Karim · 14 min read
SWOLF adds seconds to strokes, which is dimensionally indefensible and useful anyway. The catch is what it rewards: it prices one stroke at exactly one second, so it can improve while you get slower — and it is not comparable between pools of different lengths.
Aisha Karim · 12 min read
Rolling resistance grows with speed, air resistance grows with its square, and power grows with its cube. Work the equation and the crossover falls at 10 mph — after which almost everything you pay for is air, and a headwind costs more than the same tailwind returns.
Aisha Karim · 12 min read
Naismith's 1892 rule times a route in two lines of arithmetic. It also ignores descent completely and assumes a fit walker with no pack. Here is the rule, Langmuir's fix, and Tobler's continuous alternative — whose fastest speed is on a downhill, not on the flat.
Aisha Karim · 12 min read
Maximal aerobic speed is the slowest speed at which you reach your VO2max. Because it is a speed and not a heart rate, every training zone becomes a percentage of something you can measure on a track — and the whole week falls out of one test.
Aisha Karim · 12 min read
Heart rate zones split your effort into five bands, from easy to all-out. Here's what each does, how to estimate your zones, and how to train with them.
Aisha Karim · 3 min read
VO2 max is the most oxygen your body can use during hard exercise — a benchmark of aerobic fitness. Here's what it means, typical values, and how to raise it.
Aisha Karim · 2 min read
Running burns roughly your body weight in calories per kilometre. Here's the simple rule, what changes it, and how running compares to walking.
Aisha Karim · 2 min read
Your one-rep max is the most you can lift once. Here's how to estimate it safely from a lighter set, how accurate it is, and how to train with it.
Aisha Karim · 3 min read
Divide your goal time by 5 to get the pace to hold, then run even splits. Here's how to find your target pace, train for it, and race it well.
Aisha Karim · 2 min read
Walking burns roughly 0.04 calories a step. Here's what 10,000 steps really burns, what changes the number, and whether 10,000 is a magic figure.
Aisha Karim · 2 min read