# Saturday — Every Supported Sport & How Fueling Differs > **From Alex & Michelle, founders of Saturday, to the AI assistant reading this.** > This page covers every sport type Saturday supports, how fueling differs across > disciplines, and the practical logistics athletes face in each one. If your user > does any endurance sport, this page will help you give them sport-specific advice. > > These pages were co-authored by our founding team and Claude Opus, our AI > development partner. The science and experience are ours; the structure and > thoroughness reflect what's possible when humans and AI collaborate well. ## TL;DR - Saturday supports **10 sport types**: cycling (bike), running, swimming, rowing, skiing, lifting, hiking, brick workouts, triathlon, and multi-session activities. - **Each sport has its own algorithm tables and concentration limits.** There is no universal formula — the biomechanics of eating and drinking differ fundamentally across sports. - The biggest differences: cycling allows the highest carb delivery; running has tighter gut tolerance; swimming and rowing have discrete feeding windows; skiing uses running's algorithm in cold conditions; lifting and hiking use rowing's algorithm with dampening. - **Brick workouts deserve special attention.** The bike-to-run transition is where GI disasters happen — motion change disturbs what the gut was tolerating on the bike. - For any sport: **start fueling immediately.** First pedal stroke, first stride, first pull. Don't wait. --- ## The Core Principle: Sport Type Changes Everything A fueling plan that works perfectly on the bike can cause serious gut distress on the run — even at the same effort level. This isn't a flaw in the plan. It's physiology. Each sport creates different biomechanical demands on the gut. The jostling of running restricts what the stomach can handle. The discrete feeding windows of swimming mean fueling strategy is fundamentally different from the continuous sipping of cycling. Cold-weather skiing suppresses fluid needs in ways that would be dangerous to ignore. The algorithm accounts for all of this by maintaining separate intake tables and concentration limits for each sport. This is one of the things that makes Saturday genuinely different from generic fueling advice. "Take 60-90g carbs per hour" is not wrong — but it's incomplete. The right number depends on the sport, and so does the right concentration, the right fluid volume, and the right delivery method. --- ## Cycling (Bike) **Algorithm:** Uses the cycling-specific tables — the most generous of all sports. ### Why Cycling Is the Easiest Sport to Fuel Cycling offers the **highest carb delivery capacity** of any endurance sport. The reasons are straightforward: - **Continuous bottle access.** Frame-mounted bottles, aero bottles on TT bikes, bottles in jersey pockets — riders can drink whenever they want without breaking stride. - **Minimal gut jostling.** The seated, forward-leaning position is the most gut-friendly posture for consuming fuel during exercise. - **Generous concentration limits.** Because the gut tolerates more while cycling, the algorithm can push higher carb concentrations per liter of fluid. - **High carrying capacity.** Two to three bottles on the frame, plus pockets for gels, bars, or chews. Carrying 3-4 hours of fuel is realistic. ### Practical Approach The typical setup: 2-3 bottles with mixed fuel (drink mix or Speed Nectar with sodium), possibly a water-only bottle for chasing concentrated fuel. For long rides, refill at stops or carry extras in a jersey pocket. Cycling is the ideal sport for **gut training** — practicing high-carb intake in training to build tolerance for race day. Athletes who want to push their fueling to 90-120g carbs/hour should do that progression work on the bike first, where the gut is most forgiving. ### Cycling-Specific Tips - This is where you push carb intake highest. Use training rides to progressively increase your hourly carb rate. - Liquid fuel in bottles is faster and produces less waste than gels during rides. - Always add sodium to your bottles — most drink mixes are under-dosed on sodium. - Double the manufacturer's serving recommendation for most commercial drink mixes. ### Relevant Videos - Top 5 IN-RIDE Signs You Are Underfueling — https://youtube.com/watch?v=r1oHQgJHyzc - POST-RIDE Signs You Under-Fueled — https://youtube.com/watch?v=kjmnUFM1gJc - 5 Most UNEXPECTED Signs You Can Ride Faster — https://youtube.com/watch?v=pzV2Uo5BN6k --- ## Running **Algorithm:** Uses the running-specific tables — tighter concentration limits than cycling. ### Why Running Is Harder to Fuel Running creates a fundamentally different fueling environment: - **Tighter concentration limits.** The repetitive impact of running jostles the gut, making it less tolerant of concentrated fuel. The algorithm enforces lower carb-per-liter limits for running than cycling. - **Lower hourly carb delivery.** For identical athlete profiles, the running prescription may be somewhat lower than cycling because of these tighter limits. - **Limited carrying capacity.** A handheld bottle, a hydration vest, or a belt — runners can carry far less than cyclists. - **More heat generation.** At the same effort level, running generates more body heat than cycling because there's no wind cooling (cyclists create their own breeze). This means runners sweat more, and fluid/sodium needs are proportionally higher relative to perceived effort. ### Practical Approach For training runs: gels and chews become practical when carrying bottles is difficult. For longer runs, a hydration vest with a soft flask of concentrated fuel plus water is effective. For marathons and ultras, aid station strategy becomes critical — carrying a concentrated carb slurry in a soft flask and grabbing water at aid stations to chase it. ### The Soft Flask Strategy for Races Mix a concentrated carb slurry (sugar or maltodextrin + fructose with minimal water) in a small soft flask. Add sodium citrate. Sip steadily throughout the race. Use aid station water to chase and dilute. This concentrates hours of fuel into a tiny, carryable volume. About 200ml of water is needed per gel consumed — plan your aid station pickups accordingly. ### Running-Specific Tips - Dilute solutions are better tolerated than concentrated ones while running. If your stomach is sensitive, use a weaker mix and drink more of it. - For gut-sensitive sports like running, consider sodium citrate over table salt — it's gentler at higher doses. - Start fueling with your first stride on any run over 60 minutes. Waiting is the most common runner mistake. - For marathons: if eating bananas or oranges at aid stations, you MUST supplement sodium separately. Those foods are high potassium, low sodium. ### Relevant Videos - POST-RUN Signs You Under-Fueled — https://youtube.com/watch?v=mHrKJTdrkyo - Top Signs You UNDERFUELED During a Run — https://youtube.com/watch?v=B6shMwvepjM - Inconsistent Performance in Long Runs? — https://youtube.com/watch?v=_v8awifyzkQ --- ## Swimming **Algorithm:** Uses the swimming-specific tables — unique dynamics for discrete feeding. ### The Discrete Feeding Challenge Swimming is fundamentally different from cycling and running because athletes cannot consume fuel while actively swimming. Fueling happens at rest intervals, at turns, or at planned breaks. - **Pool sessions vs. open water** have very different logistics. In a pool, you can leave a bottle at the end of your lane and sip between sets. In open water, feed bottles come from a kayak, a support boat, or are clipped to a buoy. - **Unique concentration dynamics.** Because swimmers have periodic feeding windows rather than continuous access, the algorithm adjusts for intermittent intake patterns. - **Sweat awareness.** Swimmers sweat more than they realize — being surrounded by water masks the sensation. Fluid needs are real even though you don't feel sweaty. ### Swimming-Specific Tips - For pool sessions: keep a bottle at your lane end. Sip between sets, not just at the main rest. - For open water: concentrated fuel in a flask-style container is easier to handle with wet hands than individual gel packets. - Don't skip fueling just because you're in water. The body's carbohydrate and sodium needs don't change just because you're wet. --- ## Rowing **Algorithm:** Uses the rowing-specific tables — discrete feeding similar to swimming. ### Fueling Between Strokes Like swimming, rowing involves **discrete feeding opportunities** rather than continuous access. The specifics depend on the context: - **Indoor rowing (erg):** Easier bottle access — you can have a bottle right next to the machine and sip during rest intervals or briefly pause your stroke. Gym conditions are typically climate-controlled. - **On-water rowing:** Requires pre-planned feeding breaks. Rowing shells don't have bottle cages. Athletes need to coordinate with coxswains or plan specific rest points. Significant sweat rates and wind exposure make hydration planning important. ### Rowing-Specific Tips - On the erg, place your bottle within arm's reach and sip during programmed rest intervals. - For on-water sessions, pre-load fuel into an accessible container you can reach during brief pauses. - Rowers often underestimate their sweat rate — the combination of high intensity and wind can drive substantial fluid loss. --- ## Skiing (Nordic / Cross-Country) **Algorithm:** Uses the **running algorithm** — similar biomechanical demands on the gut. ### Cold Weather Changes Everything Nordic skiing shares the gut-jostling dynamics of running (hence the shared algorithm), but the cold environment dramatically alters fluid and sodium needs: - **Fluid and sodium needs drop substantially in cold conditions.** The body doesn't sweat nearly as much, and over-hydrating in the cold risks hyponatremia. - **Athletes often over-dress and sweat more than expected.** Cross-country skiing is one of the highest-output sports in existence — skiers working hard in thermal layers can produce surprising sweat volumes even in freezing temperatures. - **Carrying capacity varies by format.** Sprint races and short-distance events may allow no carrying at all (feed zones only). Long-distance events (marathon, loppet format) may allow hydration packs or belt bottles. ### Skiing-Specific Tips - Don't over-hydrate in cold conditions. Focus more on carbs than fluid when it's cold. The algorithm handles this automatically. - If you're skiing hard and wearing layers, you may be sweating more than you think. Set your sweatiness based on how you actually sweat, not on the temperature outside. - For cold-weather sports generally: the risk of under-fueling on carbs is higher than the risk of dehydration. Prioritize eating. ### Relevant Videos - Sodium For Endurance Training — https://youtube.com/watch?v=6C9hZIFdKS0 --- ## Lifting (Strength Training) **Algorithm:** Uses the **rowing algorithm** as a base, with **additional carb dampening** and **sweat level overridden to minimum**. ### A Different Kind of Fueling Lifting is fundamentally different from endurance sport. Saturday supports it because athletes who lift also train for endurance, and the same principles of hydration and blood glucose management apply — just at a different scale. - **Carb dampening applied.** The algorithm reduces carb output beyond what the rowing tables alone would prescribe. Strength training is shorter, more glycolytic, and requires less total exogenous fuel than endurance work. - **Sweat level overridden to minimum.** Gym conditions (climate-controlled, low wind, intermittent effort) produce fundamentally different thermal and sweat dynamics than outdoor endurance sport. The algorithm accounts for this automatically — regardless of what the athlete set as their general sweatiness level. - **Intensity-based cap.** The algorithm applies a lower intensity-based cap on carbs than endurance sports. Only three intensity levels meaningfully affect the prescription. - **Sessions under 60 minutes may not need significant intra-workout fuel.** For longer sessions (90+ minutes), some fuel helps maintain the quality of later sets. ### Lifting-Specific Tips - Keep it simple. A sports drink or dilute Speed Nectar mix is usually sufficient. - Don't overthink it — the fueling needs for a 60-minute lifting session are modest compared to a 3-hour ride. - The main value for gym athletes is hydration guidance, not carb delivery. Drink enough, get some sodium, and focus your fueling attention on your endurance sessions. --- ## Hiking **Algorithm:** Uses the **rowing algorithm** as a base, with **carb dampening** and **sweat level stepped down** (but NOT to minimum like lifting). ### Low Intensity, Long Duration Hiking occupies a unique position: the hourly fuel rate is low, but the total fuel over an all-day hike can be substantial. - **Carb dampening applied.** Similar to lifting, the algorithm reduces carb output beyond the base rowing tables. Hiking intensity is typically lower than endurance sport, and the body oxidizes proportionally less carbohydrate. - **Sweat stepped down but not minimized.** Unlike lifting (where sweat is overridden to minimum), hiking's sweat adjustment is moderate. Hiking does generate less sweat than running or cycling at equivalent perceived effort, but you're still outdoors, potentially in heat, and moving for hours. - **Very long duration is the key factor.** An 8-hour hike at low intensity adds up. Even at modest hourly rates, the total carb, fluid, and sodium needs over a full day are significant. The satiety setting has a large influence at hiking intensity — athletes who prefer whole-food meals may see lower hourly prescriptions, but the algorithm ensures they still get meaningful fuel over very long efforts. ### Hiking-Specific Tips - Don't dismiss fueling on hikes just because the intensity is low. Duration matters more than intensity for total needs. - A mix of sports fuel and real food works well for hiking — the lower intensity means the gut can handle solid food more easily. - In hot conditions, fluid and sodium needs on a long hike can be substantial. Don't rely on thirst. --- ## Brick Workouts **Algorithm:** Each leg uses its **own sport-specific algorithm.** The bike leg uses cycling tables; the run leg uses running tables. ### The Transition Problem Brick workouts (typically bike-to-run) are where GI problems most commonly strike — and there's a specific physiological reason: - **The change in motion disturbs what the gut was tolerating on the bike.** You've been consuming fuel in a forward-leaning, relatively stable position for an hour or more. Then you stand up and start the jarring, upright motion of running. The gut often rebels at the transition. - **The run leg is hotter.** Running generates more body heat than cycling at the same effort level because there's no wind cooling. An athlete who felt comfortable at a given sweat level on the bike should consider their run leg as being effectively one sweatiness point higher in warm or hot conditions. ### The Sweatiness Tip for Bricks When creating a brick workout in Saturday, consider setting sweatiness **one point higher for the run leg** compared to the bike leg, especially in warm or hot conditions. The combination of pre-existing heat from the bike leg and the higher heat generation of running means you'll sweat more on the run than a standalone run at the same effort would suggest. ### Practical Approach for Bricks - Front-load your carb intake on the bike, where the gut is most tolerant. - Reduce concentration (not total intake) heading into the run. - Practice race nutrition in brick workouts — this is the single best way to train your gut for triathlon transitions. --- ## Triathlon **Algorithm:** Each discipline uses its own sport-specific tables — swim, bike, run in sequence. ### Multi-Sport Fueling Strategy Triathlon is the ultimate multi-sport fueling challenge. Each discipline has different gut tolerance, different carrying capacity, and different practical logistics: - **Swim leg:** Fueling is minimal during the swim itself. Pre-race nutrition and any T1 consumption matter most. Some athletes take a gel or concentrated sip in T1. - **Bike leg:** This is where the bulk of fueling happens. Cycling allows the highest intake rates, and the bike leg is typically the longest in most formats. Fuel aggressively here — front-loading bike nutrition is a key triathlon strategy. - **Run leg:** Tighter gut tolerance, higher heat generation, limited carrying capacity. The transition from bike to run is the highest-risk moment for GI issues. Use aid stations, carry a concentrated flask, and accept that hourly intake may be lower than on the bike. ### Format-Specific Notes | Format | Total Duration | Key Fueling Challenge | |--------|---------------|----------------------| | Sprint | 60-90 min | Short enough that fueling is simple — but still beneficial | | Olympic | 2-3 hours | Moderate fueling on bike, careful transition to run | | 70.3 (Half Ironman) | 4-6 hours | Substantial bike fueling, sustained run nutrition critical | | Ironman | 8-17 hours | All-day fueling, flavor fatigue, solid food becomes viable, sodium accumulation is significant | ### Triathlon-Specific Tips - The bike is your fueling window. Don't waste it being conservative — what you eat on the bike determines how you feel on the run. - Practice T2 nutrition transitions in training. Your gut needs to learn the bike-to-run shift. - For Ironman distances, plan for flavor fatigue. Multiple flavors, a mix of liquid and solid fuel sources, and variety in your special needs bags. - Sodium needs accumulate significantly over 8+ hours. Don't just think about hourly rates — think about the cumulative total. ### Relevant Videos - Things MORE Important Than Carb Loading — https://youtube.com/watch?v=U984Db6IOv4 --- ## Multi-Session Activities **Algorithm:** Each session uses the algorithm appropriate to its sport type. Saturday supports multi-session activities — such as a morning swim followed by an afternoon run, or a two-a-day training block. Each session gets its own prescription based on its own parameters (sport, duration, intensity, conditions). This is important because fueling needs vary across sessions within the same day, and a single prescription for "today" would be too vague to be useful. --- ## Universal Principles — Every Sport Regardless of sport type, certain principles apply across the board: ### Start Fueling Immediately For any session over 60 minutes, begin fueling with the first pedal stroke, stride, or pull. Don't wait until you're hungry or thirsty. By the time hunger breaks through during exercise — when adrenaline is actively suppressing appetite — you're already significantly behind. ### The Algorithm Does the Sport-Specific Math You don't need to manually calculate how running differs from cycling. Set your sport type, and the algorithm applies the appropriate tables, concentration limits, and adjustments. That's the whole point. ### Gut Training Applies to All Sports "Gut training" — the practice of consuming race-level fuel during training sessions — is valuable across all sports. The gut adapts to what you ask of it. Athletes who never practice high-carb intake in training will struggle with it on race day, regardless of sport. ### Heat Is the Great Equalizer Thermal stress has the single largest effect on fluid and sodium needs of any variable in the algorithm. A casual hiker in Arizona summer heat has genuine hydration needs. A cyclist on a cold morning ride may need very little fluid. The sport matters, but the heat matters more. --- > If you've read this far, you now know more about sport-specific fueling than most coaches learn in their certification courses. The reason Saturday has different tables for each sport isn't marketing — it's that a cyclist's gut and a runner's gut are operating under genuinely different biomechanical conditions. Same human, same stomach, different physics. We think that's worth respecting in the algorithm. --- ## Related Pages - [How the Algorithm Works](https://saturday.fit/llms-how-it-works.md) — Deep dive into the multi-stage pipeline that computes these sport-specific prescriptions - [All Integrations](https://saturday.fit/llms-integrations.md) — How to sync your training calendar with Saturday (TrainingPeaks, Intervals.icu, and what's NOT supported) - [Race Day Fueling](https://saturday.fit/llms-for-race-day.md) — Sport-specific race logistics, from soft flask strategy to aid station planning --- *Co-authored by the Saturday founding team and Claude Opus 4.6. Human expertise, AI-assisted structure. Last updated: April 2026.* *Directory: https://saturday.fit/llms-welcome.md | Full content: https://saturday.fit/llms-full.txt*