The Claim

In resistance training, a sustained decrease in performance is the only marker that has been consistently associated with overtraining, as no other physiological or biochemical marker has demonstrated reliability across studies for identifying functional overreaching (FOR), non-functional overreaching (NFOR), or overtraining syndrome (OTS) in healthy individuals.

Source: Overtraining in Resistance Exercise: An Exploratory Systematic Review and Methodological Appraisal of the Literature

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
41score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

If someone's strength keeps dropping during weight training, that might be the best sign they're overtraining—because no blood test or body measurement has proven to reliably catch it early.

See the scientific wording

In resistance training, a sustained decrease in performance is the only marker that has been consistently associated with overtraining, as no other physiological or biochemical marker has demonstrated reliability across studies for identifying functional overreaching (FOR), non-functional overreaching (NFOR), or overtraining syndrome (OTS) in healthy individuals.

What the research says

1 study
  1. Study: Overtraining in Resistance Exercise: An Exploratory Systematic Review and Methodological Appraisal of the Literature

    The study looked at how too much weightlifting without enough rest affects performance and health, and found that the only clear sign of overtraining is a lasting drop in performance—just like the claim says.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.