【Route Tactics】Conquering the Wan Jin Shi Marathon: Decoding the Core of Pack Positioning and Negative Split Pacing Strategy on the Coastal Headwind Section

Chapter 1: Introduction: Geographic and Climatic Characteristics of the Wan Jin Shi Marathon

The New Taipei City Wan Jin Shi Marathon is Taiwan’s only top-tier marathon to receive the World Athletics Gold Label certification. The course unfolds along Taiwan’s northern coast (Wanli, Jinshan, Shimen), with the Pacific Ocean on the left and the Datun Mountain Range on the right, renowned worldwide for its spectacular coastal scenery and extremely challenging climatic conditions.

From the perspectives of marathon biomechanics and climatic physiology, the Wan Jin Shi Marathon is the ultimate test of a runner’s pacing willpower and environmental adaptability. The course characteristics of Wan Jin Shi are primarily defined by the following three points:

1. Coastal rolling terrain: Although the course largely follows the coastline, it is not completely flat. Along the way, it includes the Yehliu Tunnel, the McDonald’s Hill, and several river-crossing bridges, with undulations that rise and fall, frequently subjecting runners’ quadriceps to eccentric contraction challenges.
2. Strong northeast monsoon: Since the race is typically held in mid-March each year, the northern coast is still under the direct assault of the strong northeast monsoon. The outbound leg (Wanli to Shimen) is mostly a cross-tailwind, but on the 21.1 km return leg after the turnaround point (Shimen Junior High School), runners must face a fierce headwind of up to force 5 to 7 (wind speeds of approximately 30 - 50 km/h).
3. High humidity and low temperatures: The coastal climate is humid, with air humidity consistently above 80% year-round. Combined with low temperatures and cold rain, body heat loss occurs extremely rapidly.

On this course, many runners blindly chase speed in the first half (tailwind and gentle slopes), only to find that when they enter the headwind section in the second half, wind resistance multiplies, energy depletes rapidly, and they crash and fade in the final 10 kilometers. Therefore, mastering headwind pack positioning tactics and the “Negative Split” pacing strategy is the core key to conquering Wan Jin Shi and breaking personal bests (PB).

Chapter 2: Physiological and Mechanical Foundations: The Impact of Wind Resistance on Running Pace and Running Economy

When running on flat ground with no wind, air resistance accounts for only 2% to 4% of a runner’s total energy expenditure at a speed of 15 km/h (approximately 4:00/km pace). However, when facing strong headwinds or when running speed increases, air resistance increases exponentially.

The physical formula for running wind resistance ($F_{\text{drag}}$) is:
$$F_{\text{drag}} = \frac{1}{2} \times \rho \times C_d \times A \times (v_{\text{runner}} + v_{\text{wind}})^2$$

Where:

• $\rho$ is the air density.
• $C_d$ is the runner’s drag coefficient (dependent on running posture and body shape).
• $A$ is the runner’s frontal projection area facing the wind.
• $v_{\text{runner}}$ is the running speed.
• $v_{\text{wind}}$ is the headwind speed.

Under strong headwind conditions (such as the Wan Jin Shi return leg, where wind speed $v_{\text{wind}}$ can reach 10 m/s, or 36 km/h), even at a running speed of only 4:15/km (approximately 3.9 m/s), the relative wind speed reaches as high as 13.9 m/s. At this point, the proportion of energy expenditure attributed to air resistance skyrockets to 15% to 20%.

The Loss of Running Economy (RE)

To overcome this enormous headwind resistance, runners are forced to pay the following physiological costs:

1. Increased muscular mechanical work: To maintain the same pace, the quadriceps, triceps surae, and gluteus maximus must output greater concentric power, which significantly increases oxygen uptake ($VO_2$). This means running economy declines.
2. Disrupted running form mechanics: Strong wind forces runners to unconsciously over-lean forward or shorten their stride length. This passive adjustment increases the eccentric load on the hamstrings, easily triggering localized muscle tightness.
3. Unnecessary heart rate drift: At the same speed, overcoming a headwind raises a runner’s heart rate by 8 - 12 bpm, causing them to cross the second lactate threshold (LT2) prematurely and accelerating glycogen depletion.

Therefore, on the Wan Jin Shi return leg into the headwind, any runner fighting alone must expend more than 15% additional energy. This is precisely why “pack defense” is essential on this course.

Chapter 3: Pack Positioning and Drafting in Running: Quantifying the Mechanical Benefits on Headwind Sections

In cycling, drafting is basic knowledge; in marathon running, drafting in running likewise delivers astonishing energy-saving benefits. This was demonstrated to perfection in the recent “INEOS 1:59 Challenge.”

When a runner tucks directly behind another runner (or pacer), the runner ahead pushes the oncoming airflow to both sides, creating a low-pressure “slipstream” zone behind them.

Quantifying the Mechanical and Physiological Data of Drafting

Wind tunnel experiments and biomechanical research have confirmed:

• Wind resistance reduction: Tucking approximately 0.5 to 1.0 meters behind the lead runner can reduce the air resistance experienced by the runner by 50% to 70%.
• Metabolic savings: Drafting at 15 km/h in windless conditions can reduce maximal oxygen uptake consumption by approximately 2% to 3% (equivalent to saving 1.5 - 2 seconds of energy per kilometer).
• Headwind amplification: When facing force 5 or stronger headwinds on the Wan Jin Shi return leg, the metabolic savings from drafting are amplified 3 to 4 times. Tucking behind a pack of “three or more runners in a windbreaking formation” can save up to 5 to 8 seconds of energy per kilometer, with heart rate reduced by 5-10 bpm.

Practical Guide to Pack Positioning on the Wan Jin Shi Course

1. Find the “pace train” on the outbound leg: After the start and before the turnaround point, use the cross-tailwind section to quickly position yourself in the latter half of a small group running your target pace (e.g., the 3-hour-10-minute train). The primary task in this section is to “stay invisible”—do not take the lead and break the wind; maintain a steady cadence and breathing rhythm.
2. “Tight formation” after the turnaround: After the 21 km turnaround, the headwind hits head-on. Runners should immediately establish a “V-formation or single-file” defensive windbreaking formation with teammates in the group who have similar energy levels.
3. Dynamic positioning and rotating the lead: In the strong headwind section, never attempt a solo breakaway. If you unfortunately become isolated, moderately reduce your pace and wait for a larger group from behind to catch up, then quickly “slot in” to the pack. If everyone in the group has similar energy levels, you can adopt a cycling-style “rotating lead” tactic, where each person takes the wind for 1 kilometer before consciously yielding and dropping back to shelter. This ensures the group’s overall average pace does not suffer a cliff-edge collapse.

Chapter 4: The Physiological Advantages of Negative Split Pacing and Glycogen-Sparing Mechanisms

Marathon pacing strategies are primarily divided into three types: Positive Split (faster first half, slower second half), Even Split (equal speed in both halves), and Negative Split (slower first half, faster second half).

For a course like the Wan Jin Shi Marathon, where the second half is accompanied by severe headwinds and rolling terrain, “Negative Split” pacing is the only scientifically proven golden pacing method that minimizes finish time.

Physiological Advantages of Negative Split Pacing:

1. Glycogen Sparing Mechanism: At the start of a marathon, the body’s aerobic system is not yet fully activated. If the first half (1-21km) is run too fast, the body will primarily rely on carbohydrates for mixed anaerobic metabolism, causing rapid muscle glycogen depletion. By adopting a negative split strategy and starting the first half 5-10 seconds slower than target pace, the aerobic fat oxidation system can be smoothly activated, preserving ample glycogen “ammunition” for the headwind return leg.
2. Cardiovascular Drift Control: As exercise duration extends, core temperature rises, fluid is lost, heart rate gradually increases, and stroke volume decreases. A conservative first-half pace delays the onset of cardiovascular drift, ensuring that when the second-half headwind battle begins, heart rate still has upward safety margin.

The table below simulates a runner targeting a finish time of 3 hours 15 minutes, comparing the physiological and time outcomes of different pacing strategies on the Wan Jin Shi course:

Chapter 5: Analysis of the Wan Jin Shi Course Undulations and Tactical Adjustments Around the Turnaround Point (Jinshan, Shimen, Yehliu Tunnel)

To execute a negative split strategy with precision, one must have an intimate understanding of the key terrain nodes on the Wan Jin Shi course.

[Wanli Start] ──► [Yehliu Tunnel] ──► [Jinshan Outer Ring Road (rolling hills)] ──► [Shimen Turnaround (21km)]
                                                                                        │
[Wanli Finish] ◄── [Yehliu Tunnel] ◄── [McDonald's Hill (key test)] ◄─── [Shimen Return (headwind section)]

1. Start to 5 km (Wanli to Yehliu Tunnel)

• Terrain: Flat; the road widens after exiting the Yehliu Tunnel.
• Tactics: Control heart rate. The pack is crowded at the start—do not weave left and right and waste energy. Heart rate should be maintained below 75% of maximum heart rate, with pace 5-8 seconds slower than target pace.

2. 5 km to 20 km (Jinshan to Shimen)

• Terrain: Rolling gentle slopes and bridge crossings. The Jinshan Outer Ring Road features significant wave-like undulations.
• Tactics: Do not push hard on uphills; maintain a constant “Rate of Perceived Exertion (RPE)” rather than a constant pace. Pace on uphills may drop slightly by 5-10 seconds; on downhills, relax your stride and let gravity carry the speed back. This section is with a tailwind, so follow the pace train smoothly.

3. 21 km (Shimen Junior High School Turnaround)

• Terrain: 180-degree sharp turn at the turnaround point.
• Tactics: “Defensive posture switch.” After the turnaround, the wind direction instantly shifts from tailwind to strong headwind. Runners should immediately lean the torso slightly forward (reducing the wind-facing surface area), lower their gaze slightly downward (to keep strong wind from blowing directly into the face), and proactively merge into or establish a windbreaking small group. At this point, pacing should be based on “heart rate” rather than the real-time speed on the GPS watch.

4. 35 km mark: Jinshan McDonald’s Hill (The Ultimate Test)

• Terrain: The steep slope on the Jinshan Outer Ring Road at approximately 35 km on the return leg, commonly known as “McDonald’s Hill.” At this point, runners are in an extreme state of fatigue and facing a headwind.
• Tactics: High-cadence defense. Shorten stride length, raise cadence to above 185 SPM, reduce air time with each footstrike, and prevent quadriceps cramping on the downhill sections.

Chapter 6: Practical Pace Management and Dynamic Fueling: Energy and Hydration Scheduling for High Headwind Expenditure

In headwind and low-temperature conditions, in order to maintain body temperature and overcome wind resistance, heat-generating energy expenditure and glycogen consumption rates increase by 20-30%. Therefore, the fueling frequency at Wan Jin Shi must be higher than in regular flat races.

1. Electrolyte and Anti-Cramping Fueling

Under low-temperature, high-humidity conditions, although runners appear to sweat less, cold causes vasoconstriction and heightened urination reflexes, yet electrolyte loss remains severe.

• Strategy: Starting from the 10 km mark, salt tablets must be taken at every aid station (1 tablet every 5 km) to maintain sodium ion balance in the blood and prevent cramping in the quadriceps from eccentric contractions caused by cold and sodium deficiency on the return leg.

2. Energy Gel Supplementation Schedule (1 pack every 35-40 minutes)

To prevent energy blackout, exogenous glucose supplementation must be continuous:

• 15 minutes before the race: Take 1 pack of caffeine-free energy gel.
• During the race (every 8 km): Take 1 pack of energy gel (recommended to carry gels containing sodium).
• At the 30 km mark on the return leg: Take 1 pack of high-dose caffeine energy gel (containing 100mg of caffeine). Caffeine effectively counteracts the central nervous system fatigue produced by the prolonged headwind battle, forcing motor neurons to maintain high-frequency firing.

3. “Windbreak and Collision-Avoidance” Tactics at Water Stations

Aid stations at Wan Jin Shi are typically set up alongside open roads and are often exposed to strong winds.

• Tactics: 100 meters before entering an aid station, first observe the wind direction. Enter the station on the side with less wind resistance whenever possible. After grabbing a cup, pinch the rim to form a spout and sip the water while jogging or walking, avoiding inhaling cold water into the trachea and triggering coughing. After refueling, immediately return to your original windbreaking small group—never linger alone at the aid station for too long and get dropped.

Through rigorous execution of mechanical analysis, headwind pack defense, and negative split pacing strategy, runners can transform the storm-force resistance of the northern coast into a tactical advantage on the course, crossing the finish line at the Wan Jin Shi Marathon and conquering the challenge of the northeast monsoon.

Related Reading

• 【Route Tactics】Conquering the Wan Jin Shi Marathon: The Core Decryption of Power and Pace Management in Pack Positioning and Negative Split Strategy on the Coastal Headwind Section (Part 2) Practical Guide
• 【Race Practice】The Complete Guide to the Wan Jin Shi Marathon: Core Decryption of Pack Positioning, Negative Split Strategy, and Pre-Race Tapering Guide on the Coastal Headwind Section
• Wan Jin Shi Marathon: A Complete Guide to the Northern Coast’s Coastal Scenery and Wind Speed Challenges
• Wan Jin Shi Marathon Guide: Wind Direction Strategy and Aid Station Distribution on the Coastal Course