HSA | FSA CARDS ARE NOW ACCEPTED

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Understanding Muscle Power and the ACTN3 Gene

Muscle power is the ability to produce quick, forceful movements. It is essential for activities like sprinting, jumping, and heavy lifting. One gene known to influence muscle power is ACTN3. This gene affects the structure and function of fast-twitch muscle fibers, which generate short bursts of strength and speed. Variations in ACTN3 can shift how well those fibers perform, influencing whether your natural strengths lean toward explosive power or endurance.

How ACTN3 Influences Performance

ACTN3 encodes the protein alpha-actinin-3. When this protein is present in fast-twitch (type II) muscle fibers, those fibers are more capable of rapid, forceful contractions. Different forms of the ACTN3 gene lead to different levels of alpha-actinin-3 production, which can subtly affect athletic tendencies:

  • Some genotypes are associated with stronger fast-twitch function and better performance in power and sprint activities.
  • Other genotypes are associated with reduced alpha-actinin-3, which may favor endurance and fatigue resistance.
  • Regardless of genotype, training, nutrition, recovery, and lifestyle play major roles in determining real-world performance.

General Lifestyle, Training, and Nutrition Tips for Muscle Power

Whether you are naturally inclined toward power or endurance, these practical steps support muscle strength, speed, and recovery:

  • Training: Include resistance training, Olympic-style lifts, plyometrics, and high-intensity interval training (HIIT) to build fast-twitch capacity and neural drive. Pair power-focused sessions with mobility and recovery days.
  • Protein Intake: Aim for regular protein across meals to support muscle repair and growth. A commonly used guideline is 1.2 to 2.0 grams per kilogram body weight per day depending on activity level and goals.
  • Creatine: Creatine monohydrate is one of the most studied supplements for improving short burst performance and recovery. Typical dosing protocols include a loading phase (optional) followed by a maintenance dose.
  • Hydration and Electrolytes: Maintain good hydration and replace electrolytes during prolonged or intense workouts to preserve power output and reduce cramping risk.
  • Sleep and Recovery: Prioritize 7 to 9 hours of sleep per night and use active recovery, foam rolling, and strategic rest days to optimize adaptation.
  • Periodization: Cycle training intensity and volume across weeks and months. Use blocks focused on strength and power, followed by deloads and endurance-focused phases if appropriate.
  • Warm up and Technique: Proper dynamic warm ups and technique coaching improve neuromuscular efficiency and reduce injury risk during high-power efforts.

Diet and Supplement Considerations

Nutrition supports the adaptations you want from training. Consider these practical approaches:

  • Carbohydrates: Consume adequate carbs around intense workouts to fuel high-quality efforts and support glycogen restoration.
  • Healthy Fats: Include sources of omega-3 and monounsaturated fats for inflammation control and general health.
  • Key Micronutrients: Ensure sufficient iron, vitamin D, magnesium, and B vitamins to support energy production and muscle function. Monitoring these levels with blood tests can be helpful if deficient symptoms or high training loads are present.
  • Creatine Monohydrate: A well-studied option for increasing short-term power, strength, and recovery. Typical maintenance dose is 3 to 5 grams per day after an optional loading phase.
  • Protein Supplements: Whey, casein, or plant-based protein powders can help reach daily protein targets when whole food intake is limited.

Genetic Interpretation: ACTN3 rs1815739

The following section provides genotype-specific interpretations for the ACTN3 rs1815739 variant. Use these descriptions to understand predispositions and to inform training and lifestyle choices. PlexusDx does not provide medical advice. Always consult your healthcare provider before starting new supplements, training programs, or making changes based on genetic information.

2 effect alleles (CC) — higher fast-twitch power potential

If your genotype is CC at rs1815739, you carry two copies of the effect allele associated with functional alpha-actinin-3 in fast-twitch fibers. This profile is commonly linked to better performance in explosive, power-based activities.

  • Training: Emphasize sprint work, heavy resistance training, plyometrics, and short maximal-effort intervals to leverage natural fast-twitch capacity.
  • Volume and Recovery: Use lower rep ranges at higher loads for strength, with targeted recovery to allow neural adaptations. Include longer rest between maximal efforts to support power output.
  • Nutrition: Prioritize protein for muscle repair, adequate carbs for high-intensity training sessions, and consider creatine supplementation to further enhance short burst power and recovery.
  • Supplement Considerations: Creatine monohydrate (3 to 5 g/day maintenance) and a protein strategy to match training load. Monitor hydration and electrolytes during intense sessions.
  • Other: Work with coaches on technique to maximize safe force production. Regularly assess progress and adjust periodization to avoid overtraining.
1 effect allele (CT) — balanced power and endurance potential

If your genotype is CT, you have one copy of the effect allele and one copy of the non-effect allele, producing an intermediate profile. This balance gives flexibility across both power and endurance activities.

  • Training: Combine power-focused sessions (sprints, low-rep strength, plyometrics) with endurance and conditioning work. This mixed approach supports a wide range of athletic demands.
  • Programming: Use hybrid periodization to develop both speed and stamina. Alternate blocks that prioritize strength and power with blocks emphasizing aerobic capacity.
  • Nutrition: Maintain consistent protein intake and fuel higher intensity sessions with carbohydrates. Creatine can still provide benefits for repeated sprint and strength performance.
  • Recovery: Ensure adequate recovery between diverse session types to allow adaptations across both fast and slow fiber systems.
0 effect alleles (TT) — lower fast-twitch power potential; possible endurance advantage

If your genotype is TT, you do not produce functional alpha-actinin-3 in fast-twitch muscle fibers. This profile is associated with reduced explosive power but can align with better endurance-oriented traits.

  • Training: Focus on developing muscular endurance, technique, and aerobic capacity. You can still improve power through targeted strength training and plyometric work, though gains may be slower.
  • Programming: Prioritize higher-repetition strength work, tempo runs, and longer intervals to build stamina and fatigue resistance. Include specific power drills to maximize neuromuscular improvements.
  • Nutrition: Keep protein adequate for recovery and muscle maintenance. Carbohydrate timing remains important for quality training sessions. Creatine may still help with repeated high-intensity efforts, even with this genotype.
  • Mindset: Use genetics as one piece of information. Many athletes with this profile achieve excellent power outcomes through focused training, technique, and consistent programming.

Monitoring Progress and When to Seek Testing

Track performance with objective measures such as sprint times, vertical jump, rep max, and power outputs. If you have concerns about iron status, vitamin D, or energy levels that affect training, discuss targeted blood tests with your healthcare provider. Adjust training and nutrition based on results and professional guidance.

Important Disclaimer

PlexusDx provides educational information about genetic predispositions only. This content is not medical advice. Always consult your healthcare provider or a qualified sports professional before making changes to medications, supplements, diet, or exercise programs based on genetic information.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Muscle Power and ACTN3 rs1815739

How does the ACTN3 rs1815739 variant affect muscle power and sprint performance?

ACTN3 influences how fast-twitch (type II) muscle fibers produce rapid, forceful contractions by affecting alpha-actinin-3 production. With two effect alleles (CC), you’re more likely to have higher fast-twitch power potential linked to explosive activities. With one effect allele (CT), you may show a more balanced ability across power and endurance. With zero effect alleles (TT), functional alpha-actinin-3 in fast-twitch fibers is reduced, which may align with lower explosive power but potential endurance advantage.

What training approach is best for each ACTN3 rs1815739 genotype (CC, CT, TT)?

For CC, prioritize sprint work, heavy resistance training, plyometrics, and short maximal-effort intervals, with lower reps at higher loads and longer rests for power. For CT, use a mixed plan that combines power sessions (sprints, low-rep strength, plyometrics) with endurance/conditioning and hybrid periodization. For TT, focus more on muscular endurance, technique, aerobic capacity, higher-repetition strength work, tempo runs, and longer intervals, while still including some targeted power drills to improve neuromuscular performance.

Can nutrition and supplements improve power regardless of ACTN3 rs1815739 results?

Yes—training, nutrition, recovery, and lifestyle still strongly determine outcomes across genotypes. Key supports include regular protein intake (about 1.2–2.0 g/kg/day depending on goals), adequate carbs around intense training for fueling and glycogen restoration, and hydration/electrolytes to preserve workout performance. Creatine monohydrate (commonly 3–5 g/day after an optional loading phase) is one of the most studied options for improving short-burst performance and recovery, including repeated high-intensity efforts. Sleep (7–9 hours) and periodization also help your adaptations.

What tests can help me learn more about Muscle Power and ACTN3 rs1815739?

The Functional Health Genetic Test delivers over 750 personalized genetic insights across 10 in-depth genetic reports to support whole-body, systems-level health understanding. The Fitness and Injury Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.