By Jackie Sanders, PT, DPT
You did it! You finished your event- ran your race, swam your event, completed your tournament. Be it good, bad or ugly, the results of this season are behind you, giving you a reason to exhale! The offseason represents one of the most critical yet underutilized phases in an endurance athlete’s annual plan. Athletes seem to drift towards one of two extremes: they either turn their back on the sport and allow their training to go completely random or they view it as a time to “stay fit” or “maintain mileage”, putting in long hours of aerobic work. Both of these approaches are flawed. Rather it is, in fact, the optimal window to restore physiologic balance, rebuild tissue capacity, and address performance limiters that cannot be adequately developed during competition or high-volume training periods.
At WAVE, we emphasize an offseason approach centered on mental restoration, neuromuscular and connective tissue strengthening, and metabolic ceiling development, rather than defaulting to additional “base” mileage.
1. The Value of Mental Reprieve
Endurance sport inherently involves prolonged physical and psychological stress. Continuous goal pursuit, data tracking, and external performance pressure maintain elevated sympathetic nervous system activity and cortisol levels, which can inhibit tissue repair and neuroendocrine recovery (Meeusen et al., 2010). After a long season, it is essential to take an intentional break lasting anywhere from 10-21 days. During the time that would typically be allocated to training: try one of these breathing exercises as a way of resetting your nervous system.
A true mental and physiological reset allows for:
- Normalization of autonomic balance—a reduction in sympathetic drive and restoration of parasympathetic tone (Stanley et al., 2013).
- Improved cognitive and emotional regulation, decreasing the risk of burnout and overtraining (Gustafsson et al., 2011).
- Enhanced motivation and engagement upon returning to structured training, allowing greater training quality and adherence.
Athletes who intentionally reduce structure and external load during the offseason often demonstrate improved readiness and lower perceived exertion when reintroducing workload (and from the whole human perspective, their families and friends are happier too!)
2. Heavy Strength Training: Rebuilding the System’s Capacity
A targeted phase of heavy resistance training (4–6 repetitions at ~75–90% of one-repetition maximum) provides a potent stimulus for both neuromuscular and structural adaptation in endurance athletes. Contrary to old paradigms, strength training does not impair aerobic performance; it enhances it (Rønnestad & Mujika, 2014).
Primary mechanisms include:
- Improved neuromuscular recruitment and rate of force development, leading to greater running or cycling economy (Beattie et al., 2017).
- Increased tendon stiffness and collagen synthesis, improving force transfer and reducing energy loss during gait (Kongsgaard et al., 2007).
- Enhanced muscle fiber efficiency, allowing submaximal outputs to be achieved with less relative effort (Aagaard & Andersen, 2010).
Lifting heavy weights while in-season can impair performance due to delayed onset muscle soreness and central nervous system overstimulation, so it is often avoided, and rightfully so. However, the off season is a great time to push the strength envelope and improve brute strength, coordination and explosiveness. These adaptations translate directly into improved efficiency and reduced injury risk—outcomes unattainable through endurance training alone. See the video below for some ideas on how to progress your strength training into this range.
3. Incorporating Brief, Explosive Efforts to Enhance VO₂ Kinetics
Short, high-intensity, or plyometric efforts serve as an effective complement to heavy strength training. These sessions recruit high-threshold motor units and stimulate metabolic adaptations that increase maximal oxygen uptake (VO₂ max) and oxygen delivery kinetics (Iaia et al., 2009; Gibala et al., 2006).
Physiologic effects include:
- Enhanced mitochondrial biogenesis and oxidative enzyme activity, improving aerobic metabolism efficiency (Burgomaster et al., 2008).
- Increased capillarization and improved cardiac output, facilitating faster oxygen transport (Daussin et al., 2007).
- Improved motor patterning and elastic recoil, refining running economy and mechanical efficiency (Paavolainen et al., 1999).
Integrating 1–2 short, well-recovered explosive sessions weekly (hill sprints, short power intervals, or plyometric drills) can significantly improve performance capacity without increasing total training load. In fact, optimal training load can be less overall time due to the nature of the intensity, which leads to more available time for other life endeavors- win/win in the off season. For specific ideas: check out this video.
4. Why “More Base Miles” Is Not Constructive
While aerobic base work is foundational, extending low-intensity volume indefinitely during the offseason can become counterproductive once aerobic adaptations plateau. The vast majority of athletes are NOT limited by their aerobic capacity. In fact, losing an aerobic base takes a long time- longer in highly trained individuals. Rather, most athletes are limited in performance by their overall strength or muscular endurance, as opposed to their cardiovascular systems. Given this, putting in long hours of slow duration training is often not necessary (and boring). Keeping in mind that extremely high volume loads gains are often seen in professional athletes who have copious amounts of time, time that most athletes don’t have given the other demands of their lives.
Excessive base mileage:
- Reinforces repetitive stress on tissues already adapted to similar loads (Soligard et al., 2016).
- Limits time and recovery resources for strength and neuromuscular development.
- Maintains chronic low-level fatigue that blunts responsiveness to higher-intensity training blocks (Seiler, 2010).
Simply adding volume does not equate to improved performance. The offseason should prioritize raising capacity (strength, tissue tolerance, oxygen kinetics)—not maintaining workload. This often leads to physical and psychological burnout that creeps in midway through the season.
5. Applying the Principles
A well-structured offseason program should integrate:
- A defined mental and physical recovery phase (1–3 weeks of reduced structure and total load).
- Progressive heavy resistance training, emphasizing compound lifts and movement quality.
- Brief explosive or power sessions targeting oxygen kinetics and neuromuscular efficiency.
- Avoidance of excessive, unstructured base mileage that perpetuates fatigue and asymmetry.
These strategies optimize the body’s readiness to absorb higher volumes and intensities later in the training cycle, resulting in improved performance resilience and longevity. Whether this past season was a breakout year or didn’t meet your expectations, use this off season period as a much needed reset and then productive time to improve yourself as an athlete and person!