The Lytework framework
The SALT Framework
A decision framework for managing hydration under real conditions. Not a prescription — a system for knowing what to adjust, when, and why.
Hydration has four variables. Most athletes only manage one.
Standard hydration advice treats fluid intake as the primary lever. SALT separates the four inputs that govern hydration performance — Sodium, Amount, Load, and Timing — so you can adjust each independently based on conditions, not habit. When conditions change, not everything needs to change. SALT tells you what does.
The variable that changes most — and gets managed least.
Sodium is not a fixed requirement. It is a function of your sweat rate, your sweat sodium concentration, the heat load, and how long you are out. Two athletes doing the same session can lose several grams of sodium difference per hour. A fixed drink cannot account for that.
- Temperature rises above your training baseline
- Session extends beyond 90 minutes
- You notice salt stains, cramping, or late-session flatness
- You are racing in heat you have not trained in
Base dose. 1 capsule / hr as starting point.
Moderate increase. 1–2 capsules / hr.
High demand. 2–3+ capsules / hr.
Why this matters: Replacing fluid without adequate sodium does not restore electrolyte balance. Plasma sodium concentration can decline even when you feel hydrated — affecting cardiovascular stability and perceived effort before you know something is wrong.
Fluid intake is dynamic. Drink to thirst, not to a schedule.
Fluid needs fluctuate moment to moment with temperature, intensity, and body size. Overdrinking is as problematic as underdrinking for many athletes — it can dilute plasma sodium and contribute to fluid retention without improving performance.
- Drink to thirst as the primary signal in most conditions
- In extreme heat, preemptive intake may be warranted — guided by sweat rate, not habit
- Monitor urine colour and body weight change across training blocks
- Fluid and sodium are independent dials — adjusting one does not require adjusting the other
The key distinction: Lytework capsules separate sodium from fluid entirely. When you need more sodium in heat, you take another capsule — not another bottle. You are not forced to overdrink to hit a sodium target.
Carbohydrate needs are driven by intensity — not by sodium loss.
Carbohydrate requirements are governed by exercise intensity, duration, and gastrointestinal tolerance. They do not scale with sweat rate. Bundling carbs and sodium into a single drink forces a trade-off — adjusting one changes the other, regardless of what your body actually needs.
- Keep your carbohydrate plan steady based on session intensity and duration
- When gut tolerance drops in heat, reduce carbs — not sodium
- Lytework capsules add zero carbohydrate — sodium stays controlled independently
- Do not use electrolyte drinks to hit sodium targets if the sugar load compromises gut function
30–60g / hr. Adjust sodium independently for heat.
60–90g / hr. Sodium need rises with duration.
80–120g / hr. Sodium is the variable, not carbs.
Start earlier than you think. By the time you feel it, you are behind.
Sodium depletion does not produce clear early signals. Athletes typically feel the consequence — cramping, elevated RPE, performance loss — well after the physiological deficit has accumulated. Timing is about staying ahead, not catching up.
- Begin sodium intake within the first 15 minutes of sessions exceeding 90 minutes
- In heat, dose pre-session with your first capsule before you start sweating
- Space intake evenly — every 45–60 minutes — rather than front-loading or reacting late
- During taper, prioritise sodium storage when fluid intake increases and sweat loss drops
The taper mistake: Athletes arriving at races with low plasma sodium despite hydrating well. When fluid intake rises without sufficient sodium, excess water is excreted and plasma volume does not expand effectively. Sodium timing matters even when you are not sweating heavily.
How the four variables
interact under load
When one variable changes, it does not always require changing the others. SALT helps you identify the right lever.
| Scenario | Sodium (S) | Amount (A) | Load (L) | Timing (T) |
|---|---|---|---|---|
| Heat rises mid-session | Increase dose | Drink to thirst | No change | Next capsule earlier |
| Session extends beyond planned duration | Continue dosing | Maintain intake | May reduce | Do not skip doses |
| GI distress in race | Maintain or increase | Reduce slightly | Reduce carbs | Space doses further apart |
| Taper week / pre-race | Increase — storage focus | Drink to thirst | Reduce | Begin earlier in day |
| Cool conditions, short session | Base dose or skip | Low | Maintain | Less critical |
How to use SALT in training
Use the Lytework Sodium Calculator to estimate your sweat sodium loss based on sweat rate, session length, and conditions. This is your starting dose — not a permanent prescription.
Use the Sweat Rate Calculator to estimate fluid loss per hour. Default to thirst as your primary signal. In heat, apply a mild preemptive strategy based on your output data.
Set your carbohydrate plan based on session intensity and duration. Treat it as a fixed variable. When gut tolerance changes, reduce carbs — not sodium. Lytework capsules add nothing to your carb load.
Start sodium within the first 15 minutes of any long or hot session. Dose consistently every 45–60 minutes. Adjust frequency with conditions — not reactively after you feel the deficit.
Find your sodium target. Build your protocol.
The SALT framework tells you what to adjust. The Lytework calculator tells you where to start.
SALT is a decision framework based on exercise physiology principles. It explains what to adjust and why — not a universal prescription. Individual needs vary by sweat rate, environment, intensity, and tolerance. Use in conjunction with your personalised Lytework calculator output.