Individuals exhibit low accuracy in estimating their proximity to volitional failure during high-repetition resistance training sets.

Study: “Just One More Rep!” – Ability to Predict Proximity to Task Failure in Resistance Trained Persons

The study found that people who lift weights regularly are not good at guessing how many more reps they can do before failing, which matches the claim that they are poor at estimating this.

Study: Factors influencing the accuracy of the repetition in reserve scale in resistance training: a systematic review

The study looked at how well people can guess how close they are to muscle failure during exercise and found they are worse at it when doing many repetitions, which matches the claim.

Study: Accuracy in Estimating Repetitions to Failure During Resistance Exercise

The study shows people are actually pretty good at guessing how many more reps they can do when they're close to failure, which goes against the claim that they're bad at it.

Study: Accuracy of Intraset Repetitions-in-Reserve Predictions During the Bench Press Exercise in Resistance-Trained Male and Female Subjects

The study found people are actually pretty good at guessing how many reps they have left before failing during weightlifting, which goes against the claim that they are bad at it.