Four notes from the sheet

Heavy slow resistance, HSR, is a way of loading a tendon with high force and a long time under tension. In the room we write it as a calf raise or a knee-dominant lift, three or four sets of six to eight, with an eccentric tempo of three to six seconds. The concentric is not a bounce. If the metronome is at 60 and we want a four-second lower, you hear four clicks on the way down. That is the whole idea.

People arrive having “done heel raises”. The usual version is twenty quick repetitions at the kitchen step, finished because the burn arrived. That session has a use as a warm-up. It is a poor HSR dose. The tendon sees little time at high load, and the next morning tells you almost nothing about whether a heavier week is safe.

We place isometric holds in front of HSR when the person cannot yet control the lowering portion. A 45-second mid-range hold at RPE 7 is a cleaner first week than a sloppy six-second eccentric. Once the hold is stable, the same joint angle becomes the start of the slow lift. The 24-hour symptom response rule still applies: if the stairs are worse the next morning, last night’s tempo was too ambitious, even if the bar looked modest.

HSR is not a bodybuilding tempo and it is not a powerlifting pause. We are not chasing a pump and we are not peaking a one-rep max. We are trying to give a tendon a reason to adapt without asking it to store energy yet. Energy-storage loading — the hops — comes later, on a different line of the sheet, with a counted plyometric dosage.

The numbers in this note are a teaching sketch. Illustrative example of a typical block. Not a client record.

The acute-to-chronic load ratio is a comparison. Acute load is what you did this week. Chronic load is the average of the previous four weeks. Divide the first by the second and you get a figure that rises when a quiet month is followed by a busy one. In Kallang that often looks like a runner who took March easy and then accepted four social 10-kilometre loops in a single week in May.

We pick one currency. Kilometres for a runner. Court-minutes or change-of-direction contacts for a racquet player. We do not add a strength session’s tonnage into the same ratio. Mixed units make a tidy number that means nothing. The studio sheet already has a separate column for HSR load; it does not need to be laundered through the outdoor ratio.

A ratio between about 1.0 and 1.3 is where we like to sit while someone is still rebuilding. That is a preference, not a law. A 1.5 week can be the correct week if it is a planned race and the 24-hour responses before it were quiet. A 1.1 week can be the wrong week if the hop battery dropped and the limb symmetry index widened. The ratio starts the conversation. It does not end it.

People sometimes treat 1.5 as a cliff. We do not. We treat a sudden jump as a reason to look at the calendar and at the next morning. If both are ugly, we write a deload week: volume down, isometric holds kept, no new plyometric dosage. If the calendar is ugly and the mornings are fine, we still ask whether the extra kilometres were sport that matters.

This is coaching arithmetic. It is not a medical risk score. Urbanfitnesssingapore provides exercise coaching, not medical care. We do not diagnose injuries and we do not replace your doctor or physiotherapist. If you have pain, see a clinician first; we are happy to work alongside them.

Sweat rate, for our purposes, is body mass lost in an hour of known work, adjusted for fluid drunk. Weigh yourself to the nearest 0.1 kg before an easy outdoor bout, note what you drink, weigh again after. A loss of 0.6 kg after 0.4 litres drunk is a useful planning number for the next similar hour. It is not a laboratory hydration panel and we do not treat it as one.

Heat acclimatisation is the slower process of doing repeated work in the climate you will actually use. In Singapore that climate is already here. What changes is how much outdoor volume a person can keep when they have spent six weeks only in an air-conditioned room doing isometric holds. The first outdoor weeks should not also be the hottest hours and the longest bouts.

When someone can only train after 19:00, we do not pretend they have a dawn option. We shorten the first runs, we keep cadence easy, and we do not add a new hop dosage on the same evening. Ground contact that looks tidy at 06:30 often looks sloppy at 20:15 after a desk day. The sheet should say so, rather than blaming the tendon for a heat problem.

Indoor HSR stays useful on the worst humidity days. A four-second eccentric calf raise in the room still loads the tissue when a 6-kilometre loop would be a poor idea. That is not softness. It is matching the dose to the hour you actually have.

Illustrative example of a typical block. Not a client record. If you faint, cramp severely, or feel unwell in the heat, that is a clinical problem, not a coaching tweak.

The hop battery at Urbanfitnesssingapore is a short, repeatable set: a single hop for distance, a triple hop, and a crossover hop when the floor allows. We measure distance and we watch the landing. We then calculate a limb symmetry index — weaker side as a percentage of stronger side — so the conversation is about a figure, not about a vibe.

Exit criteria are the marks we wrote at the load audit. A typical set is: hop LSI inside the band we set for that person; single-leg heel-raise endurance within a stated gap; two consecutive fortnights of prescribed sport volume without a 24-hour flare that forced a deload week; and a clinician’s constraint, if one exists, still respected. Missing one item means we are not done, even if the hop looks springy.

Energy-storage loading can look impressive before the weekly volume is back. That is the usual trap. A person hops well in the room on Tuesday and plays three social matches on Saturday. The acute-to-chronic load ratio jumps, the next Monday heel is loud, and the hop battery the following fortnight is worse. The hop was never the whole test. The week around the hop was.

We also refuse to treat a single symmetry number as a universal pass mark. Some people have hopped unevenly for years. If that pattern is old, quiet, and unchanged across two reviews, we may accept it and watch the 24-hour rule instead. If the index widens as we add plyometric dosage, we take the dosage back down. Cadence and ground contact on an easy run are supporting notes, not exit criteria of their own, unless running is the only sport on the sheet.

Ready, in this studio, is a completed list. It is not a feeling on a good morning in September. When the list is complete we write a four-week maintenance sheet and we stop. That ending is part of the method.