Article
Acute Muscle Damage Score Overview
Benjamin T. House, Andy J. Galpin, Dan Garner, Vince Kreipke, and Thomas R. Wood

What Is the Muscle Damage Score?

Both endurance and resistance exercise can cause acute (short-term) muscle damage [1-6]. As someone accumulates more training, signals of acute muscle damage will generally be less pronounced and dissipate faster [7-10]. In general, more highly trained individuals will not get as sore after intense training and will recover more quickly. However, athletes still tend to have higher levels of these markers compared to the general population [11, 12], and with higher training volumes some individuals may display long-term elevations of these markers [7, 11, 12]. The Acute Muscle Damage score aggregates all of the validated biomarkers that are associated with muscle damage into one integrated value. The thresholds are set to differentiate between standard training-induced changes and those associated with more significant acute muscle damage. A yellow or red on this score indicates that muscle damage is likely present.

Keywords: Muscle Damage, Training, Recovery

Associated Biomarkers

Female Biomarkers Male Biomarkers
AST AST
ALT ALT
LDH LDH
Creatine Kinase Creatine Kinase

Experienced Physiological Effects:

  • Delayed onset muscle soreness (DOMS)
  • Increased muscle stiffness
  • Decreased range of motion

Physiology Deep Dive:

Creatine kinase (CK), alanine aminotransaminase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) are muscle damage markers that are sensitive to acute training and can remain elevated for 24 to 96 hours post-exercise [1-6]. In some scenarios, these markers may be able to pick up acute increases in training load [13, 14]. Acute muscle damage can decrease strength, range of motion, sprinting, change of direction, and endurance performance [10, 15-19].

Constraint Zones:

Dark Green:

No overt blood biomarker signs of acute muscle damage. It is very unlikely that there is any significant exercise-induced residual muscle damage.

Green:

A limited degree of acute muscle damage is likely present due to previous exercise-induced muscle damage over the last 24 to 96 hours. It is very unlikely that there is any significant exercise-induced residual muscle damage. Consult the Training Stress Signal to assess whether your current training regimen may be outpacing recovery capacity.

Yellow:

Some degree of acute muscle damage is likely present due to previous exercise-induced muscle damage over the last 24 to 96 hours. Consult the Training Stress Signal to assess whether your current training regimen may be outpacing recovery capacity. If you have not exercised intensely in the last 24 to 96 hours, we recommend seeing a primary medical provider.

Red:

Muscle damage is likely present due to previous exercise over the last 24 to 96 hours. Consult the Training Stress Signal to assess whether your current training regimen may be outpacing recovery capacity. If you have not exercised intensely in the last 24 to 96 hours, consulting a primary care provider is recommended.

References

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