Best Supplements for Runners & Cyclists 2026: What Actually Works

18 min read
Sports supplements and vitamins for endurance athletes

The Evidence-Based Tier List

Tier 1 (Strong Evidence): Caffeine, Creatine, Beet Root/Nitrates, Sodium Bicarbonate

Tier 2 (Moderate Evidence): Beta-Alanine, Iron (if deficient), Vitamin D (if deficient)

Tier 3 (Limited/Mixed): BCAAs, Tart Cherry, Collagen, Adaptogens

Skip: Most "proprietary blends," testosterone boosters, fat burners, most pre-workouts

90% of supplements are marketing hype backed by cherry-picked studies. This guide focuses on what's actually proven to work for endurance athletes, with dosing protocols and product recommendations.

Tier 1: Proven Performance Enhancers

1. Caffeine - The Legal Performance Drug

Why It Works

  • Performance gain: 2-4% improvement in endurance performance
  • Mechanism: Blocks adenosine receptors, reduces perceived effort
  • Optimal dose: 3-6mg/kg body weight, 30-60 min before exercise
  • For a 70kg athlete: 200-400mg (roughly 2-4 cups of coffee)
BEST CAFFEINE

Nutricost Caffeine Pills 200mg

Pure caffeine without the jitters of energy drinks. Third-party tested, no fillers. Perfect for precise dosing. Take 1-2 pills 30-60 min pre-race.

  • • 200mg per pill (easy to dose)
  • • 250 capsules per bottle
  • • Third-party tested for purity

2. Creatine - Not Just for Bodybuilders

Why Endurance Athletes Should Consider Creatine

  • Improved interval capacity: Better repeated sprint performance
  • Enhanced recovery: Faster glycogen replenishment
  • Brain function: Cognitive benefits during heat/altitude
  • Dose: 3-5g daily (no loading needed)
  • Weight gain: ~1-2kg water weight initially (stabilizes)
BEST CREATINE

Thorne Creatine Monohydrate

NSF Certified for Sport - safe for tested athletes. Micronized for better absorption. Thorne is trusted by pro teams and Olympic athletes. No fillers, just pure creatine.

  • • NSF Certified for Sport (drug-tested safe)
  • • 5g per scoop
  • • 90 servings per container

3. Beet Root / Nitrates - Free Speed

The Science of Nitric Oxide

  • Performance gain: 1-3% improvement in time trials
  • Mechanism: Converts to nitric oxide, improves oxygen efficiency
  • Dose: 300-600mg nitrate (roughly 500ml beet juice)
  • Timing: 2-3 hours before exercise
  • Best for: Events lasting 5-30 minutes (biggest benefit)
BEST BEET ROOT

Beet It Sport Nitrate 400

The brand used in most beet root research. Concentrated shots with standardized nitrate content (400mg per shot). Used by pro cycling teams. No mess, precise dosing.

  • • 400mg nitrate per 70ml shot
  • • Research-backed dosing
  • • Convenient shot format
$40/15 shots View on Amazon

Tier 2: Situational Benefits

4. Beta-Alanine - For High-Intensity Efforts

When Beta-Alanine Helps

  • Best for: Efforts lasting 1-10 minutes (think: 5K, criterium racing, HYROX)
  • Mechanism: Buffers lactic acid, delays "the burn"
  • Dose: 3-6g daily for 4+ weeks (loading required)
  • Side effect: Harmless tingling (paresthesia) at higher doses
BEST BETA-ALANINE

NOW Sports Beta-Alanine Powder

Pure beta-alanine from a trusted brand. Unflavored powder mixes easily. Third-party tested. Split into 2-3 doses throughout the day to minimize tingling.

  • • 2g per scoop
  • • 250 servings per container
  • • Informed Sport certified

5. Iron - The Hidden Performance Limiter

Iron for Endurance Athletes

  • Who needs it: Female athletes, vegetarians, heavy sweaters, high-mileage runners
  • Get tested first: Check ferritin levels (optimal: 50-100 ng/mL for athletes)
  • Warning: Don't supplement without blood work - excess iron is harmful
  • Absorption tip: Take with vitamin C, avoid with coffee/tea/calcium
BEST IRON (IF NEEDED)

Thorne Iron Bisglycinate 25mg

Chelated form for better absorption and less GI distress. NSF Certified for Sport. Only supplement if blood work shows deficiency.

  • • 25mg iron bisglycinate
  • • NSF Certified for Sport
  • • Gentle on stomach

6. Vitamin D - The Sunshine Vitamin

ESSENTIAL VITAMIN

NOW Vitamin D3 5000 IU

Most athletes are deficient, especially in winter. Supports immune function, bone health, and muscle function. Test levels annually and dose accordingly.

  • • 5000 IU per softgel
  • • Take with fat for absorption
  • • Test levels: aim for 40-60 ng/mL

Recovery Supplements

7. Tart Cherry - Natural Anti-Inflammatory

RECOVERY

Cheribundi Tart Cherry Juice

Contains anthocyanins that reduce inflammation and muscle soreness. Studies show improved recovery when consumed post-exercise. Also may improve sleep quality.

  • • 8oz serving = 50 cherries
  • • Take post-workout or before bed
  • • Also available in concentrate
$36/12 pack View on Amazon

8. Omega-3s - Foundational Health

FOUNDATIONAL

Nordic Naturals Ultimate Omega

High-quality fish oil with excellent EPA/DHA ratio. Reduces inflammation, supports heart health, aids recovery. Third-party tested for purity.

  • • 1280mg omega-3s per serving
  • • 650mg EPA / 450mg DHA
  • • Third-party tested, no fishy taste

What to Skip

Supplements That Don't Work (Despite Marketing)

  • BCAAs: If you eat adequate protein, BCAAs add nothing. Waste of money.
  • Testosterone Boosters: None work. If you have low T, see a doctor.
  • Fat Burners: Caffeine is the only ingredient that does anything - just take caffeine.
  • Most Pre-Workouts: Proprietary blends with under-dosed ingredients. Get caffeine + beta-alanine separately.
  • HMB: Minimal benefit for trained athletes.
  • Glutamine: No benefit if protein intake is adequate.

The Priority Order

  1. 1. Sleep: 7-9 hours of quality sleep beats any supplement
  2. 2. Nutrition: Adequate protein, carbs, and whole foods first
  3. 3. Training: Consistent, smart training matters most
  4. 4. Hydration & Electrolytes: See our electrolyte guide
  5. 5. Then supplements: Caffeine, creatine, beet root for that final 2-5% edge