Super Shoes vs. Shedding Kilos

You can buy speed these days. Carbon plates, bouncy foam, €300 super shoes, they promise performance, and they often deliver.

But not all gains come in a shoebox.

Some of the most meaningful improvements come from within. From what you change, what you shed, what you build.

Take weight, for example. Losing a few kilos, done right, can make you more efficient, faster, and lighter on your feet. No tech required.

So which gets you closer to that sub-3 goal… cutting-edge shoes, or trimming the engine?

The answer isn’t simple. It depends on your body, your stride, your training, and your priorities.

But one thing’s certain, if you're aiming to run under three hours, knowing where your biggest gains come from, and which ones are in your control, is a conversation worth having.

Let’s break it down.

The Baseline: Our Runner (me)

• Goal: Sub-3:00 marathon (2:59:44)

• Target pace: 4:16/km or 6:52/mile

• Current weight: 72 kg (159 lbs)

We’ll compare time gains from:

• Wearing super shoes

• Losing 1–4 kg of body mass

Option 1: The Magic of Super Shoes

Modern “super shoes” (think Nike Vaporfly, Adidas Adios Pro) combine carbon plates and responsive foams to boost running economy (RE) by approximately 1–4%. That’s less energy used to run at the same pace, exactly what you want over 42.2 km.

Time Gained (for a 3:00 marathoner)

Reality Check: You’re (Probably) Not Getting 4%

The original 4% claim came from studies on elite runners.

Typical Benefit Distribution

• 0–1%: ~10–15% of runners

• 1–2%: ~25–30%

• 2–3%: ~35–40% (most common)

• 3–4%: ~10–20%

• 4%: ~1–3% (rare)

Traits That Boost the Benefit

• Midfoot or forefoot strike

• Body mass under 65–70 kg

• High cadence and short ground contact

• Good running economy

• High weekly mileage

Traits That Reduce the Benefit

• Heel striking

• Body mass over 75–80 kg

• Overstriding

• Low training age or weekly mileage

Option 2: The Power of Weight Loss

Here’s the old-school rule of thumb:

1 pound lost = ~1 second/mile faster
That’s roughly 57 seconds per kg in the marathon.

Time Gained from Weight Loss

This only works if you're losing non-functional mass (excess fat). If you're already quite lean, aggressive weight loss can backfire. But for many runners, shedding 2–4 kg offers consistent, predictable gains.

Personal note: I’m not a Clydesdale, I still know I race best about 4 kg below my current weight or roughly 7% lighter - that’s nearly 4 minutes saved!

Head-to-Head: Super Shoes vs. Weight Loss

Verdict: Super shoes offer more top-end potential, but the combination of modest weight loss and racing in super shoes is often the game-changer.

What Adds Time? Sneaky Time Killers for 3-Hour Runners

We’ve talked about gains. Now, here are the things that can sabotage your sub-3 attempt, often by several minutes.

1. Heat

Every 1°C above 10°C adds about a 0.3% performance penalty.

• 15°C = ~2.7 minutes slower

• 20°C = ~5.4 minutes slower

• 25°C = ~9.0 minutes slower

• 30°C = 10+ minutes slower

Can you adapt? Yes. With 7–14 days of heat training (sauna use, overdressing, or training in warm weather), athletes can reduce this predicted penalty dramatically. Conversely, if you typically train in warm weather you can get a time benefit from choosing a cold race.

2. Poor Fueling & Hydration

• Missed carbs = bonking, cramps, GI issues

• Dehydration = fade, fatigue
  Time loss: 5–15 minutes

3. Pacing Errors

• Too fast in the first half leads to major fade
  Time loss: 3–10 minutes

4. Weak Taper

• Non-optimal taper = flat, overtrained, or both
  Time loss: 2–5 minutes

5. Course & Conditions

• Hills, headwinds, rough surfaces
  Time loss: 2–8 minutes

Final Thoughts: Control What You Can

The road to sub-3 isn’t just about training harder, it’s about stacking smart gains and avoiding unnecessary losses.

Train smart. Fuel right. Pace evenly. Race cool. Run light.

You’ll get there.