Resistance training for runners: complex or simple solutions?

Testing

Following the third running bout at 16kmh, the subjects performed a ramped maximal running test to exhaustion. This test was used to determine each subject’s maximal aerobic capacity (V02max). Beyond measuring the impact on running performance, the researchers wanted to know the impact of the different training interventions on neuromuscular performance.  One-repetition maximum performance (where the subjects lifted the heaviest weight possible during a squat using good form, was measured to test lower body strength. Power production was measured as well; the subjects were tested for maximal countermovement jump height, which consists of quickly squatting down and then jumping as high as possible. To gain more insight into power production, the peak power during countermovement jump, expressed relative to body weight was also measured.

An effective countermovement jump can be produced through two different strategies. First, individuals can use muscular strength to accelerate their body into the air.  Alternatively, they can rely on the elastic properties of their tissues to jump high. Therefore, squat jump performance was tested, where the subjects squat down, paused to let accumulated energy dissipate, and then jumped. Meanwhile, drop jump performance was measured by asking the subjects to step off a small box and upon landing, immediately jump as high as possible. This jump allows subjects to accumulate more elastic energy that they can use to jump higher.

By comparing the height of the squat jump, countermovement jump, and depth jump, it’s possible to gain insight into the energy contributions to the jump, as well as how these relationships change because of a training intervention; a relatively high squat jump implies an emphasis on muscular power to create a jump, while a high drop jump indicates the ability to effective use elastic energy to jump high. 

Finally, the authors calculated what’s known as the reactive strength index or RSI. The higher the jump that’s performed, and the less time the foot is in contact with the ground, the higher the RSI. RSI is an excellent indicator of the ability to use elastic energy to create a lot of force in very little time. In sum, these tests provided a complex picture of how each training intervention impacted neuromuscular performance and the determinants of endurance performance.

What they found

When training and testing was performed, and the numbers crunched, it became apparent that both interventions had a powerful impact on performance. Both training protocols lead to increases in maximal squat performance, countermovement jump, countermovement jump peak power, squat jump, drop jump, and RSI. However, the complex training group saw significantly greater performances than the resistance training group in countermovement jump peak power, drop jump, and RSI. This is an important finding because these are performance qualities one would expect to benefit from plyometric training. They involve high-force, high-speed movements, similar to plyometrics. While strength training alone can improve these qualities (as indicated by the improvements seen resistance training only group) they’re preferentially improved by higher speed trained by activities that require high-speed contractions.

During the run-specific training, improvements did occur, although they were not as dramatic as the neuromuscular testing results. Both groups improved their VO2max, and running economy at 14 and 16kmh (see figure 1) but not at 12kmh and also reduced their blood lactate concentrations at 14 and 16kmh but not 12kmh. No changes in heart rate were demonstrated. As with the neuromuscular performance testing, more dramatic performance improvements were seen from the complex training. The complex training subjects had lower levels of blood lactate concentration and greater improvements in running economy, with no significant differences between groups in VO2max. These results indicate that as with neuromuscular performance, complex training leads to superior improvements in running performance as well. As fast and efficient running relies highly on the effective use of elastic energy, training that directly addresses these qualities will lead to performance benefits.

Figure 1: Running economy improvements before and after complex vs. resistance training

Practical implications

Resistance training is now an accepted performance strategy for endurance runners, and as the results of this study show, it is an effective one. However, that doesn’t mean it is the only non-running training tool that is effective, and if used alone, it’s unlikely to be a complete approach to performance development. To effectively challenge the elastic running qualities necessary for optimizing performance, plyometric exercises are very valuable. Importantly, they can be easily and effectively combined with strength training exercises, allowing for more efficient training. Not only does complex training involving traditional resistance training and plyometrics improve the key neuromuscular qualities for fast and efficient running, it also directly enhances running performance by lowering the metabolic and energetic cost of running.

When implementing these findings, start small. If you’re already performing resistance training, consider placing one or two smaller sets of plyometric exercises after each 1-2 lower body resistance training exercises. Match the general movement pattern of the two exercises for optimal effect – for example, drop jumps after squats. If these plyometric exercises are well tolerated, carefully and patiently expand the volume and intensity of the exercises over time, whenever you want to emphasize these qualities. It’s a simple and effective way to improve running economy, one of the most important performance determinants in running!

References

1. Front Physiol. 2025 Nov 12:16:1718150.  doi: 10.3389/fphys.2025.1718150.  eCollection 2025.