Low energy availability can result in an increase in training days modified or lost as a result of injury and/or illness. This can also result in an inability to compete in competitions, as a result of injury and illness. For example, in a cohort of male and female Olympic athletes, low energy availability was associated with illness in the prior month.

Athletes with low energy availability can have a decreased response to training. This means that despite intensified training, athletes with REDs often show a decrease in performance. For example, in a cohort of elite female swimmers, those with low energy availability swam slower after a period of intense training.

Athletes with low energy availability may have a harder time recovering from training or competition. This can be seen through direct self-report failure to recover between training, as well as with biomarker testing.

Low energy availability can result in decreased cognitive performance/skill. This includes reduced reaction time, impaired judgement, and decreased coordination, decreased concentration.

Low energy availability and REDs can result in decreased motivation. This may manifest as decreased wellbeing, irritability and depression, mood disturbances, in addition to other aspects of motivation. All aspects can interfere with sports performance.

Low energy availability can result in decreased muscle strength.

Athletes with low energy availability can experience a decrease in endurance performance. This can include reduced performance in endurance activities, such as reduced rowing or running performance, as well as a decrease in maximal oxygen consumption.

Athletes with low energy availability have a decrease in power performance in anaerobic activities. For example, athletes with low energy availability had decreased performance during 15 second cycling sprints and 400m swim trials.