The current investigation aimed to examine the ecological validity of self-reported wellness questionnaires, and specifically ‘Readiness to Train’ (RTT) as an indicator of pre-training and pre-competition preparedness within elite Gaelic football players. Thirty-seven (n = 37) elite male Gaelic football players (age 26 ± 4; height 181 ± 15 cm, weight 86 ± 4 kg) were recruited for the current study which took place during the 2017 competition season. Participants were monitored using global positioning system technology (GPS; 10-Hz; STATSports Viper Pod; STATSports; Newry, UK) and a self-reported questionnaire (Metrifit, Health, and Sport technologies, Ireland) to provide measures of internal load (RPE; sRPE) external load (GPS variables) and wellness questionnaire (Likert scale: 1–5 response) response to training loads. Results showed that irrespective of the model that the percentage RTT prior to training or match-play was not associated with and running performance measures. Activity type (p ≤ 0.0001), muscle soreness (p ≤ 0.0001), sleep quality (p ≤ 0.0001), and sleep duration (p ≤ 0.0001) all effected subsequent running performance during training and match-play. Furthermore, post hoc analysis showed that specific GPS variables and accumulated training load across specific time durations impacted RPE and total internal training load. Our results indicate that RTT is a poor measure of pre-training and competition preparedness, with individual sub-scales of wellness more appropriate to measure preparedness within Gaelic football players. Practitioners should pay close attention to fluctuations in sleep quality, sleep duration, and muscle soreness when planning training loads. Also, accumulated training loads impact players running capacity and perception of RPE highlighting the importance of longitudinally planning within the Gaelic football training process.