Sports Training I: the Characteristics and Principles of Sports Training, Training Load, its Features, Principles and the Adaptation Process, the Means and Methods of Executing Training Load, and Overload and Overtraining, their Causes, Symptoms and Remedial Measures

Training load is the stimulus applied to the athlete. External load is the work performed: its intensity (how hard: speed, weight lifted, percentage of maximum, heart rate), volume (how much: distance, duration, number of repetitions, total tonnage), density (the relation of work to rest within a session), duration and frequency (sessions per week). Internal load is the athlete's physiological and psychological response to that work, measured by heart rate, blood lactate and the rating of perceived exertion (RPE, on Borg's 6–20 scale or a 0–10 category-ratio scale). The session-RPE method multiplies the athlete's RPE on a 0–10 scale by the session's duration in minutes: a 60-minute session rated 7 gives a load of 420 arbitrary units. Intensity and volume are inversely related: as one rises the other must usually fall. The principles of load are that it must be adequate (above the threshold for adaptation), progressive, alternated with recovery, varied, individual and specific.

Adaptation follows a predictable course. A training load causes fatigue and a temporary fall in performance capacity; during recovery the body restores its resources and, if the load was adequate and the rest long enough, rebuilds them above the previous level: supercompensation, the model associated with the Soviet biochemist Nikolai Yakovlev. If the next load comes during the supercompensation phase, capacity rises step by step; if it comes too soon, before recovery, fatigue accumulates; if it comes too late, the gain is lost. The process reflects Hans Selye's general adaptation syndrome (alarm, resistance, exhaustion), which also explains how excessive load without recovery ends in exhaustion. The fitness–fatigue model (Banister) treats each session as producing both a fitness effect and a fatigue effect, with performance their difference, which is why a taper before competition lets fatigue fall faster than fitness.

Intensity for endurance training is often set by heart rate. The Karvonen method uses the heart rate reserve (HRR = HRmax − HRrest): target heart rate = ((HRmax − HRrest) × intensity) + HRrest. Maximal heart rate is conventionally estimated as 220 − age. For a 20-year-old with a resting heart rate of 60 training at 70 per cent: HRmax = 200, HRR = 140, 140 × 0.70 = 98, and 98 + 60 = 158 beats per minute. For a 40-year-old with a resting rate of 70 at 60 per cent: HRmax = 180, HRR = 110, 110 × 0.60 = 66, and 66 + 70 = 136. The 220 − age estimate is only a population average: individuals vary by about 10–12 beats per minute either way, so a directly measured maximum is better where possible, and alternatives such as Tanaka's 208 − 0.7 × age give different values, especially in older people. Taking a straight percentage of HRmax instead of the reserve gives a lower target at the same nominal intensity.

The means of training are the exercises used: general exercises that develop all-round fitness, special (specific) exercises that develop the abilities and technique of the sport, and competition exercises, the event itself performed under competition conditions. The methods are the ways the load is organised. The continuous method is uninterrupted work at a steady or varying intensity for long periods, for aerobic endurance. The interval method alternates work with incomplete recovery: extensive intervals at moderate intensity with many repetitions and short rests develop aerobic endurance, and intensive intervals at high intensity with fewer repetitions develop anaerobic capacity and speed endurance. The repetition method uses near-maximal efforts with complete recovery, for speed and maximal strength. Fartlek, or "speed play", devised by Gösta Holmér in Sweden in the 1930s, varies pace freely over natural terrain. Circuit training, developed by R. E. Morgan and G. T. Adamson at the University of Leeds in the 1950s, moves the athlete through a series of stations, each exercising a different muscle group or ability. Weight or resistance training uses free weights, machines or body weight, and plyometric training uses rapid stretch–shortening actions such as bounding and depth jumps to develop explosive power; its ideas come from the "shock method" of the Soviet coach Yuri Verkhoshansky.

Overload in the training sense is necessary: without it there is no adaptation. The syllabus's "overload, its causes, symptoms and remedial measures" refers to excessive overload, the state in which load persistently exceeds the athlete's capacity to recover. The European and American colleges of sports medicine (2013) describe a continuum: functional overreaching, a short-term fall in performance recovered within days to a couple of weeks and followed by supercompensation, which is planned; non-functional overreaching, in which performance stays down for weeks to months; and overtraining syndrome, a prolonged maladaptation lasting months or longer. Causes include rapid increases in load, too little recovery between sessions, monotonous training, too many competitions, inadequate sleep and nutrition (especially low energy and carbohydrate intake), illness, travel and psychological stress from study, work or relationships.

Symptoms are physiological (declining performance despite continued training, persistent fatigue, heavy legs, a raised resting or morning heart rate or, in some endurance athletes, a lowered one, slower heart-rate recovery, loss of body weight and appetite, disturbed sleep, frequent colds and infections, and overuse injuries), psychological (mood disturbance, loss of motivation, irritability, depression, anxiety and loss of concentration, shown on a Profile of Mood States by a reversal of the iceberg profile) and hormonal and biochemical (changes in cortisol and testosterone, which are hard to interpret alone). Because no single test diagnoses it, overtraining is recognised by monitoring over time and by excluding illness. Remedial measures are to reduce or stop training according to severity, with complete rest in true overtraining syndrome; to restore sleep, nutrition and hydration; to treat illness; to reduce other stresses and provide psychological support; to return gradually with low-intensity, varied training; and, above all, to prevent it by planning load with recovery weeks, monitoring load, mood, heart rate and performance, individualising training and avoiding sudden jumps in load.