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How CKM Variants Affect Power and Endurance

Power and endurance are two sides of the same athletic coin. Power describes the ability to generate force quickly — think sprinting or jumping — while endurance is the capacity to sustain effort over time, such as during long runs or cycling. The CKM gene helps determine how muscles store and use energy during both types of activity. CKM encodes the muscle-specific form of creatine kinase, an enzyme that converts creatine into phosphocreatine, a rapidly available energy reservoir used during short, intense bursts of exercise and to quickly regenerate ATP during sustained efforts.

Genetic variations in CKM can influence how efficiently this energy system works. Different alleles at the rs8111989 position can be associated with differences in muscle energy metabolism, which may subtly affect power output and endurance capacity. No genotype determines destiny. Nutrition, hydration, training, sleep, and recovery all interact with genetics to shape performance. Below we summarize what each genotype may mean and provide practical, actionable steps to support muscle energy metabolism.

Genotype Interpretations

2 effect alleles (TT) — Potentially reduced CKM efficiency

If your genotype is TT at rs8111989, you carry two copies of the effect allele. This configuration is associated with a higher likelihood of reduced efficiency in converting creatine to phosphocreatine. That may translate to a modest disadvantage in both explosive power and sustained endurance because muscles may not access rapid energy reserves as readily as others.

What this might mean for you

  • Explosive activities (sprints, heavy lifts, plyometrics) could feel more taxing, and recovery between short maximal efforts may be slower.
  • Longer efforts might require a bit more pacing or strategic fueling to maintain intensity.
  • Training and nutrition adjustments can often compensate for these differences.
1 effect allele (CT) — Mild variation in CKM function

If your genotype is CT, you carry one copy of the effect allele. This may cause slight differences in the creatine-to-phosphocreatine conversion process. Effects are usually smaller than for TT but may still influence how quickly muscles access and regenerate energy during high-intensity efforts.

What this might mean for you

  • You may notice modest variability in short-burst power or how you feel during repeated intervals.
  • Endurance performance is unlikely to be markedly affected, but attention to fueling and recovery will help maintain steady performance.
  • Targeted training and supportive nutrition can optimize your muscle energy system.
0 effect alleles (CC) — Typical CKM function

If your genotype is CC, you carry two copies of the non-effect allele. This is associated with the typical CKM enzyme function and standard conversion of creatine into phosphocreatine. Muscles generally have a balanced capacity for both power and endurance activities related to this pathway.

What this might mean for you

  • You likely have standard muscle energy availability for short, intense efforts and sustained activity.
  • Performance differences will more often come from training, nutrition, and recovery rather than this specific genetic marker.
  • Maintaining good dietary and lifestyle habits will preserve muscle energy function.

Practical Nutrition Strategies

Regardless of genotype, you can support muscle energy metabolism with targeted nutrition. Focus on consistent intake and timing to provide the substrates your muscles need:

  • Protein: Aim for 1.2 to 2.0 grams per kilogram of body weight per day depending on training phase. Prioritize complete protein sources such as lean meats, fish, eggs, dairy, soy, and legumes to support muscle repair and synthesis.
  • Creatine-containing foods: Red meat and seafood contain creatine. Regular inclusion can help, but amounts from food alone are modest compared to supplementation.
  • Carbohydrates: For endurance sessions and high-intensity intervals, prioritize carbohydrates for glycogen replenishment. Choose whole grains, fruits, starchy vegetables, and sports fuels around long workouts.
  • Timing: Consume a balanced meal with carbohydrates and protein 2 to 3 hours before intense sessions. Use a small carbohydrate-rich snack 30 to 60 minutes before shorter high-intensity efforts if needed.
  • Hydration and electrolytes: Maintain hydration before, during, and after activity. Electrolyte-containing fluids can help during long or hot workouts to preserve muscle function.

Supplement Considerations

Supplements can be appropriate tools when paired with proper training and nutrition. Discuss these with your healthcare provider before starting.

  • Creatine monohydrate: One of the most studied performance supplements. Typical dosing is a 3 to 5 gram daily maintenance dose. Creatine can increase muscle phosphocreatine stores, improve short-term power output, and support recovery between bouts of high-intensity work. It is generally well tolerated.
  • Protein powders: Useful for meeting daily protein targets when whole-food intake is insufficient. Whey, casein, and plant-based blends are options depending on tolerance and preference.
  • Electrolyte supplements: Helpful during prolonged sessions or heavy sweating to maintain fluid balance and muscle function.
  • Beta-alanine: May help with buffering during repeated high-intensity efforts, useful for activities lasting 1 to 4 minutes. Consider under guidance if you perform repeated anaerobic bouts.

Training and Lifestyle Recommendations

Your genotype provides one piece of the puzzle. Combine genetics-aware strategies with solid training and lifestyle habits to maximize results:

  • Balanced training: Combine strength work (to boost muscle mass and maximal power) with specific endurance sessions (to improve aerobic capacity and energy efficiency).
  • Interval training: Short, repeated high-intensity intervals with controlled recovery can improve both phosphocreatine recovery and aerobic capacity. Progress volume and intensity gradually.
  • Recovery and sleep: Aim for 7 to 9 hours of quality sleep per night. Sleep supports muscle repair, hormonal balance, and metabolic recovery.
  • Periodization: Plan cycles of training that vary intensity and volume to avoid overtraining and to allow physiological adaptations.
  • Monitor response: Pay attention to how your body responds to workouts and nutrition. Adjust fueling, rest, and supplement use based on performance and recovery.

When to Consider Testing and Professional Support

If you are a competitive athlete or you want a tailored plan that integrates genetic information, consider working with a coach, sports dietitian, or healthcare provider who understands exercise genetics. They can help interpret genotype results in the context of your performance goals, current fitness, and medical history.

Important Disclaimer

PlexusDx provides information about genetic predispositions to help you understand potential influences on health and performance. PlexusDx does not provide medical advice. The content in this article is educational only and should not be used to diagnose or treat medical conditions. Always consult your healthcare provider, sports medicine specialist, or a registered dietitian before making changes to your diet, supplement routine, or training plan.