Potential REDs performance outcomes that can result from problematic LEA
| Spoke | Examples of direct or indirect impairment | Athletic populations with LEA (assessed directly or via surrogates) providing evidence of impairment |
| Decreased athlete availability (illness and injury) | Increase in training days lost or modified due to illness or injury (eg, impaired preparation) Inability to compete at key competitions due to illness or injury | Tier 4* FA (n=85) and MA (n=47) Olympic athletes from 11 different sports10
Tier 4 FA (n=55) and MA (n=26) Olympic athletes from 11 different sports269 Tier 4 FA endurance athletes (n=45)214 Tier 4 FA endurance athletes (n=13)274 Tier 3 FA college athletes (n=116) from endurance, power and team sports275 Unspecified Tier FA high-school athletes (n=163) from endurance, power and team sports276 Unspecified Tier FA high-school athletes (n=249) from aesthetic, endurance and team sports277 A mix of Tier 1–4 FA (n=833)270 Tier 2 FA figure skaters (n=137)278 Tier 4 FA endurance athletes (n=13)274 Unspecified Tier FA high school athletes (n=163) from endurance, power and team sports276 |
| Decreased training response | Decreased rather than increased performance of treadmill protocol following 4 weeks intensified training plus 2 weeks recovery Reduced performance of 5 km on-water rowing following a period of intensified training Reduced swimming velocity in 400 m time trial after 12 weeks of training Self-reported reduction in training response Decreased aerobic (4000 m time trial) and anaerobic (15 s) performance after 2 weeks intensified training including inadequate energy intake | Tier 2 club level FA endurance runners (n=16)71
Tier 4 national level MA (n=5) and FA rowers (n=5)279 Tier 3 junior national level FA swimmers (n=10)168 Unspecified mixed tier FA (n=1000)8 Tier 3 MA road cyclists (n=13)106 |
| Decreased recovery | Direct: self-reported failure to recover between training sessions Indirect: reduced glycogen synthesis Indirect: reduced muscle protein synthesis Indirect: reduced PCr recovery | Tier 4 FA (n=8) and MA (n=4) lightweight rowers76
Tier 3 MA endurance runners (n=7)48 Tier 1 MA (n=6) and FA (n=7) endurance athletes261 Unspecified tier resistance-trained FA (n=7) and MA (n=8)257 Tier 2 FA (n=19) endurance athletes280 |
| Decreased cognitive performance/skill | Reduced reaction time Self-reported impaired judgement and decreased coordination and concentration | Tier 4 FA endurance athletes (n=30)184
Unspecified tier FA (n=1000)8 |
| Decreased motivation | Decreased well-being Increase in total mood disturbance (eg, fatigue, vigour) Self-reported increase in irritability and depression Emotional lability Increased irritability Increase in total mood disturbance and general stress Self-reported decrease in mood, emotional self-regulation, concentration, social interaction, food anxiety | Tier 3 MA endurance athletes (n=18)90
Tier 4 national level MA (n=5) and FA rowers (n=5)279 Unspecified tier FA (n=1000)8 Tier 2–4 Mix of sports FA (n=8)67 Tier 3 Endurance FA (n=10) and MA (n=2)67 Tier 3 MA Road cyclists (n=13)106 Tier 4 FA (n=8) and MA (n=4) lightweight rowers76 |
| Decreased muscle strength | Decreased neuromuscular strength Decreased explosive power (countermovement jump) Decreased explosive power (countermovement jump, reactive jump) Decreased concentric hamstring peak torque Decreased isometric bench press Decreased one rep max squat, bench press, deadlift Decreased concentric and eccentric peak force | er 4 FA endurance athletes (n=30)184
Tier 3 MA endurance athletes (n=18)90 Tier 2–3 MA bodybuilder (n=1)281 Tier 2 junior elite FA cross country skiers (n=19)282 Tier 2–3 MA bodybuilder (n=1)85 Tier 2–3 FA fitness competitors (n=27)188 Tier 2–3 MA bodybuilder (n=1)244 Tier 2–3 FA physique athlete (n=1)283 |
| Decreased endurance performance | Decreased performance of treadmill run protocol Reduced 5 km on-water rowing performance Decreased neuromuscular endurance Self-reported reduction in endurance performance Decreased VO2 max Apparent underperformance in 60 min functional power threshold vs training load Decreased performance of 4000 m time trial Self-reported decrease in rowing performance | Tier 2 club level FA endurance runners (n=16)71
Tier 4 national level MA (n=5) and FA rowers (n=5)279 Tier 4 FA endurance athletes (n=30)184 Unspecified Tier FA athletes (n=1000)54 Tier 3–4 FA endurance athletes (n=33)284 Tier 3 MA road cyclists (n=50)18 Tier 3 MA road cyclists (n=13)106 Tier 4 FA (n=8) and M (n=4) lightweight rowers76 |
| Decreased power performance | Reduced velocity during 400 m swim time trial Decreased anaerobic (Wingate) performance Decreased number of throws in a Judo Specific Fitness Test Decreased performance of 15 s cycling sprint | Tier 3 junior national level FA swimmers (n=10)168
Tier 2–3 MA bodybuilder (n=1)50 Tier 2 MA second and third Dan black belt Judo athletes (n=11)104 Tier 3 MA road cyclists (n=13)106 |
Each outcome can occur in the absence of LEA; therefore a differential diagnosis should always be considered in the assessment of REDs severity and/or risk.
*Tiering system according to McKay et al.31
FA, female athlete; MA, male athlete; PCr, phosphorylated creatine; VO2 max, maximal oxygen consumption.