In most cases the training regime of middle to long distance runners will consist of well, running and not much else. Naturally you’d assume that the most effective way to get better at long distance running is to run long distances, which in part is absolutely right. However, studies have shown that two to three strength training sessions per week can benefit the performance of middle and long distance runners.
‘Effects of Strength Training on the Physical Determinants of Middle- and Long-Distance Running Performance: A Systematic Review’ written by Richard C. Balgrove
Methods Electronic databases were searched using a variety of key words relating to ST (strength training)exercise and distance running. This search was supplemented with citation tracking. To be eligible for inclusion, a study was required to meet the following criteria: participants were middle- or long-distance runners with C 6 months experience, a ST intervention (heavy resistance training, explosive resistance training, or plyometric training) lastingC4weeks was applied, a running only control group was used, data on one or more physiological variables was reported. Two independent assessors deemed that 24 studies fully met the criteria for inclusion. Methodological rigor was assessed for each study using the PEDro scale.
Results PEDro scores revealed internal validity of 4, 5, or 6 for the studies reviewed. Running economy (RE) was measured in 20 of the studies and generally showed improvements (2–8%) compared to a control group, although this was not always the case. Time trial (TT) performance (1.5–10 km) and anaerobic speed qualities also tended to improve following ST. Other parameters [maximal oxygen uptake (VO2max), velocity at VO2max, blood lactate, body composition] were typically unaffected by ST.
For middle-distance (800–3000 m) runners, cardiovascular-related parameters associated with aerobic energy production can explain a large proportion of the variance in performance [11–17]. However a large contribution is also derived from anaerobic sources of energy [14, 18]. Anaerobic capabilities can explain differences in physio- logical profiles between middle- and longer-distance runners  and are more sensitive to discriminating performance in groups of elite middle-distance runners than traditional aerobic parameters . Anaerobic capacity and event-specific muscular power factors, such as vVO2max and the velocity achieved during a maximal anaerobic running test (vMART) have also been proposed as limiting factors for distance runners [12, 20, 21]. For an 800-m runner in particular, near-maximal velocities of running are reached during the first 200 m of the race , which necessitate a high capacity of the neuromuscular and anaerobic system.
Both RE and anaerobic factors, (i.e., speed, anaerobic capacity and vMART) rely on the generation of rapid force during ground contact when running [23, 24]. Programs of ST provide an overload to the neuromuscular system, which improves motor unit recruitment, firing frequency, musculotendinous stiffness, and intramuscular co-ordination, and therefore potentially provides distance runners with a strategy to enhance their RE and event-specific muscular power factors . In addition, an improvement in force-generating capacity would theoretically allow athletes to sustain a lower percentage of maximal strength, thereby reducing anaerobic energy contribution . This reduction in relative effort may therefore reduce RE and blood lactate (BL) concentration. As vVO2max is a function of RE, VO2max and anaerobic power factors, it would also be expected to show improvements following an ST intervention. Several recent reviews in this area have provided compelling evidence that a short-term ST intervention is likely to enhance RE [10, 26], in the order of * 4% . Whilst these reviews have provided valuable insight into how ST specifically impacts RE, studies also typically measure other important aerobic and anaerobic determinants of distance running performance, which have not previously been fully synthesized in a review. Body com- position also appears to be an important determinant of distance running performance, with low body mass conferring an advantage [27, 28]. Resistance training (RT) is generally associated with a hypertrophic response ; however, this is known to be attenuated when RT and endurance training are performed concurrently within the same program . Changes in body composition as a consequence of ST in distance runners have yet to be fully addressed in reviews on this topic.
· Strength training appears to provide benefits to running economy, time trial performance and maximal sprint speed in middle and long distance runners of all abilities
· Maximal oxygen uptake, blood lactate parameters, and body composition appear to be unaffected by the addition of ST to a distance runner’s program.
· Adding ST, in form of heavy resistance training, explosive resistance training, and plyometric training performed, on 2-3 occasions per week is likely to positively affect performance.