Goals ›

Fitness

Exercise performance, strength, endurance and recovery.

Strongest evidence: Iron, Whey Protein and Essential Amino Acids.

Supplements for fitness

Each supplement gets the grade of its strongest fitness benefit. Open one to see each benefit.

StrongModerateWeakNo trials
SupplementMain effects in studiesEvidenceBenefits studied
IronIron stores +Hgb, Endurance +VO2Strong4 of 10
Whey ProteinMPS +40-100%, Lean mass +4kgStrong8 of 10
Essential Amino AcidsAmino retention +15%, Lean mass +2.5kgStrong6 of 10
Branched-Chain Amino AcidsAnabolic signaling +mTOR, Muscle preservation +gainsStrong9 of 10
ElectrolytesCramp threshold +0.86 Hz, Pain -0.7 scaleStrong5 of 10
Hyaluronic acidLess pain, faster recovery, +23pp adhesionsStrong1 of 10
MagnesiumStrength/mg +1.02, Muscle relaxation +20%Strong3 of 10
Nitrate↑ exercise tolerance, ↓ angina/ischemiaStrong5 of 10
Vitamin DStrength/mass +25(OH)D, Falls/function ↓; +25(OH)DStrong1 of 10
CreatineStrength/lean mass +10–30%, Sprint power/endurance +8–35%Strong5 of 10
Showing 10 of 142 supplements.

What fitness covers

10 benefits that studies measure, and the supplements with the strongest evidence for each.

Workout performance

How well you perform in a single training session: power, work completed and how hard it felt. It is measured by power output, total volume lifted and rated perceived exertion.

36 supplements, 11 strong
  1. IronStrong, 117
  2. CreatineStrong, 60
  3. Branched-Chain Amino AcidsStrong, 53
  4. Essential Amino AcidsStrong, 51
  5. CaffeineStrong, 35

Endurance

How long you can keep going at a given effort. It is measured as time to exhaustion, as distance covered in a fixed time, and as VO2 max, the maximum oxygen the body can use.

69 supplements, 12 strong
  1. IronStrong, 316
  2. NitrateStrong, 74
  3. CreatineStrong, 54
  4. ElectrolytesStrong, 33
  5. CaffeineStrong, 30

Strength

How much force a muscle can produce. It is measured as a one-repetition maximum, as grip strength, and as peak force on a dynamometer.

22 supplements, 7 strong
  1. IronStrong, 110
  2. Essential Amino AcidsStrong, 60
  3. Branched-Chain Amino AcidsStrong, 59
  4. CreatineStrong, 59
  5. Whey ProteinStrong, 54

Muscle growth

Muscle getting bigger, which is separate from getting stronger. It is measured as lean mass on a DXA scan, as muscle thickness on ultrasound, and as muscle fibre size on a biopsy.

23 supplements, 11 strong
  1. Whey ProteinStrong, 140
  2. Essential Amino AcidsStrong, 88
  3. Branched-Chain Amino AcidsStrong, 79
  4. LeucineStrong, 45
  5. CreatineStrong, 33

Muscle maintenance

Keeping the muscle you already have, during ageing, illness, bed rest or a period of eating less. It is measured as lean mass over time and by markers of muscle being broken down.

28 supplements, 11 strong
  1. Vitamin DStrong, 86
  2. MagnesiumStrong, 64
  3. Whey ProteinStrong, 58
  4. CalciumStrong, 57
  5. Branched-Chain Amino AcidsStrong, 39

Exercise recovery

How quickly the body returns to normal after hard exercise. It is measured by muscle damage markers such as creatine kinase, by how fast strength comes back, and by soreness over the following days.

72 supplements, 10 strong
  1. IronStrong, 164
  2. Hyaluronic acidStrong, 91
  3. Branched-Chain Amino AcidsStrong, 44
  4. Omega-3 fatty acidsStrong, 40
  5. MagnesiumStrong, 30

Muscle soreness

The ache that arrives a day or two after unfamiliar exercise, called delayed-onset muscle soreness. It is measured on a visual analogue scale at fixed hours afterwards, and by pressure pain threshold.

17 supplements, 2 strong
  1. Essential Amino AcidsStrong, 18
  2. GlucosamineStrong, 14
  3. L-CarnitineModerate, 8
  4. ElectrolytesModerate, 7
  5. Type-II CollagenModerate, 6

Muscle cramps

Sudden involuntary muscle contractions, usually in the legs and often at night or during exercise. Trials count how often they happen, how long they last and how much they hurt.

5 supplements, 4 strong
  1. ElectrolytesStrong, 40
  2. MagnesiumStrong, 21
  3. CalciumStrong, 20
  4. PotassiumStrong, 16
  5. DiosminModerate, 6

Body composition

What the body is made of, rather than what it weighs: fat mass, lean mass and bone. It is measured by DXA scan, bioelectrical impedance or skinfolds, and two people at the same weight can differ completely here.

19 supplements, 9 strong
  1. Essential Amino AcidsStrong, 125
  2. Whey ProteinStrong, 85
  3. Branched-Chain Amino AcidsStrong, 63
  4. GlutamineStrong, 44
  5. LeucineStrong, 43

Protein source

The substance supplying protein and its amino acids. What matters is the amount, the amino acid profile and how well it is digested, rather than any effect beyond supplying protein.

10 supplements, 7 strong
  1. CaseinStrong, 46
  2. AlanineStrong, 45
  3. Branched-Chain Amino AcidsStrong, 29
  4. GlutamineStrong, 27
  5. L-SerineStrong, 26

Protocols for fitness

What studies used, for this goal or for a group of people. Not advice: talk to a doctor first.