digest
Short Summary
Main recommendation: Rather than canceling a training session outright when fatigue signals appear, scale the session down by lowering intensity and volume while still keeping enough work to support hypertrophy, using measurable local and systemic markers to decide how much to modify. Soreness, blood biomarkers, sleep, heart rate variability, resting heart rate trends, and motivation are used together, and single-day readings should not drive decisions on their own.
Key Points
- Use soreness as a first local check: around 3 out of 10 is acceptable, above 3 warrants questions, and above 6 suggests not training that muscle group.
- Soreness is subjective, so judge whether it eases once warmed up; a muscle that is still stiff only after warm-up is a sign to adjust.
- When damage or overload seems chronic rather than a single bad day, blood work can be used to check markers of muscle breakdown.
- Track trends over more than three days, ideally more than five, rather than reacting to one day's numbers.
- Consider training phase (in season, preseason, postseason, offseason) when deciding whether to cancel, modify, or continue.
Details Worth Noting
- Concrete instructions:
- Rate local soreness on a 0 to 10 scale. If it is about 3 or less, proceed. If it is above 3, ask questions about the session. If it is above 6, do not train that muscle group.
- Warm up and reassess: if stiffness resolves after warm-up, it is generally fine to proceed.
- Dr. Galpin suggests tracking resting heart rate changes over time, watching for elevation sustained over three to five consecutive days.
- Track sleep changes and, if available, heart rate variability, which the speaker describes as more sensitive to training-induced overload than resting heart rate.
- If the goal is hypertrophy and you must reduce work, aim to keep volume: train at about 6 out of 10 RPE, reduce range of motion, switch to machines, or substitute an easier movement (for example, leg extension instead of squat).
- A light option given: about 50 percent load, with sets like a set of 10 for three sets, to promote blood flow, then move on and resume the next day.
- Blood markers mentioned: creatine kinase (common marker of muscle damage), LDH, myoglobin (released when muscle breaks down; linked to rhabdomyolysis, where urine can turn very dark), and ALT and AST.
- Dr. Galpin cites an AST to ALT ratio of about 1.67 as a threshold associated with higher muscle damage risk, and says that once AST outpaces ALT (ratio above 1), it's a notable sign of muscle damage.
- Motivation can also signal a need for rest: if you train hard, enjoy it, and still cannot push yourself, that may indicate it is not the day or week to push.
Bottom Line
Fatigue decisions are best made by combining soreness, trends in sleep and heart rate, and blood markers over several days, then scaling the session down rather than skipping it when hypertrophy is the goal.
