Functional overreaching

Functional overreaching is a deliberate increase in training that briefly lowers performance, followed by recovery and performance above the previous level.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 145.} Recovery takes a few days or weeks, which allows coaches to plan an overload phase followed by a taper.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 145.},^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 123.}

Zatsiorsky and colleagues call overreaching functional when recovery takes a week or two and performance improves afterward, and nonfunctional when recovery takes longer without improvement.^{3Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 195.} Continuing to intensify training without enough rest can move a client toward overtraining syndrome.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 145.}

In practice

A classic example is a final maximal training session a few weeks before competition, followed by a gradual taper into the event.^{1Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 145.} A mismanaged overreaching phase can do harm rather than improve performance.^{2Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 123.}

Responses differ: in one heavy overload study built on 10 sets of 1RM, 73% of subjects lost more than 4.5 kg (9.9 lb) from their 1RM, while some kept progressing.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 125.} Training status and genetics both influence how quickly overreaching develops.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 125.}

Where sources differ

Rippetoe argues that the roughly two-week line between overreaching and overtraining is arbitrary and ignores training status.^{5Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 40.},^{6Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 41.} Advanced lifters may need four or more weeks to recover and supercompensate as a normal part of training, so he prefers to call planned hard periods “overload” and treat them as adaptive.^{5Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 40.},^{6Rippetoe et al., Practical Programming for Strength Training, 3rd ed., p. 41.}