Protocol · Metabolic Disorders
McArdle Disease (GSD Type V) Supportive Care Protocol
Creatine Monohydrate and Vitamin B6 (Pyridoxine) are the core of this stack, with 5 supporting supplements. Each row gives the amount the protocol lists and the grade our evidence database holds for that supplement in McArdle Disease (GSD Type V) Supportive Care.
We are re-verifying the studies cited on protocol pages; only confirmed citations are shown.
The stack
7 supplements · 1 graded
| Grade | Supplement | Amount listed | Why it’s in the stack | Evidence on file |
|---|---|---|---|---|
| Primary stackThe core of this protocol | ||||
| Creatine Monohydrate | Amount listed: 60 mg/kg/day (loading not recommended - can worsen symptoms) | Alternative energy source for muscles; may help improve exercise tolerance and reduce myoglobinuria
| Grade C for Exercise Tolerance3 studies · 28 people | |
| Vitamin B6 (Pyridoxine) | Amount listed: 50–100 mg daily | Co-factor for muscle glycogen phosphorylase b; may partially compensate for enzyme deficiency | Not graded yet | |
| Supporting stackListed as additions to the core | ||||
| Oral Glucose/Sucrose | Amount listed: 30–40 g sucrose/glucose 30–40 min before exercise | Pre-exercise glucose improves exercise tolerance by providing blood-borne fuel | Not graded yet | |
| Branched-Chain Amino Acids (BCAAs) | Amount listed: 5–10 g before and during exercise | Alternative fuel source for muscles; may provide energy during exercise | Not graded yet | |
| Coenzyme Q10 | Amount listed: 100–300 mg daily | Supports mitochondrial function; may help with muscle energy production | Not graded yet | |
| Ribose | Amount listed: 5–15 g daily in divided doses | Supports ATP regeneration; may help muscle recovery | Not graded yet | |
| Carnitine | Amount listed: 1–2 g daily | Supports fatty acid oxidation; may help muscles use fat for energy | Not graded yet | |
How this protocol works
In plain language
McArdle Disease (Glycogen Storage Disease Type V) is a rare inherited muscle disorder caused by deficiency of the enzyme myophosphorylase, which breaks down glycogen (stored sugar) in muscles. Without this enzyme, muscles cannot efficiently convert glycogen to glucose for energy during exercise.
KEY FEATURES:
- Onset typically in childhood/early adulthood
- Exercise intolerance - fatigue, pain, cramping with activity
- "Second wind" phenomenon - improvement after 10 minutes of rest
- Risk of rhabdomyolysis (muscle breakdown) with intense exercise
- Dark urine after exercise (myoglobinuria)
SYMPTOMS:
- Muscle fatigue and weakness during exercise
- Muscle cramps and stiffness
- Muscle pain (myalgia)
- Exercise intolerance
- Burgundy-colored urine after intense exercise (dangerous sign)
THE "SECOND WIND":
A hallmark of McArdle disease - after 6-10 minutes of exercise, symptoms improve as the body switches to alternative fuel sources (blood glucose, fatty acids).
CRITICAL: McArdle disease requires specialist management. This protocol is SUPPORTIVE ONLY.
MANAGEMENT STRATEGIES:
- Aerobic conditioning (supervised, gradual)
- Pre-exercise carbohydrate intake
- Pacing activities with the "second wind"
- Avoid intense/anaerobic exercise
- Hydration to protect kidneys
- Recognize and stop if symptoms of rhabdomyolysis occur
Creatine* may provide alternative energy for muscles (use low doses).
Pre-exercise glucose/sucrose* improves exercise tolerance.
B6* is a cofactor that may help residual enzyme activity.
Expected timeline: Lifelong condition. Proper management can significantly improve quality of life and exercise tolerance.