Overreaching: Why This Zone Is a Warning
What LODE has detected
Your recent training load is significantly higher than what your body has been consistently handling over the past few weeks. LODE calculates this using your Exponentially Weighted Moving Average (EWMA), a method that gives more weight to your most recent runs and less to older ones, so it reflects your current physiological state as accurately as possible. When your recent load outpaces your established fitness base by too large a margin, you've entered the Overreaching zone.
Why this matters
Research is consistent: the relationship between sudden load spikes and injury risk is one of the most replicated findings in sports science. A landmark cohort study of 5,205 runners (Nielsen et al., British Journal of Sports Medicine, 2025) found that completing a single run more than 10% longer than the longest run in the previous 30 days raised overuse injury risk by 64%. When weekly load climbs sharply relative to your chronic baseline, soft tissues (tendons, bones, and connective tissue) come under mechanical stress that outpaces their capacity to adapt and repair.
This doesn't necessarily mean you're injured. It means the balance between stress and recovery has tipped too far in the wrong direction. Left unaddressed, tissue stress accumulates faster than the body can repair it — tendons lose their load tolerance, bones accumulate microdamage, and muscles fail to fully recover between sessions. This is how overuse injuries develop: not from one bad run, but from a pattern of load that consistently outpaces the body's ability to rebuild (Gabbett, 2016; Nielsen et al., 2025).
What to do
Prioritise rest for the next 1–3 days. You don't need to stop running permanently, you need to let your chronic load "catch up" with your recent activity. Easy walking, sleep, nutrition, and passive recovery are the most effective tools right now. When your load trend returns to the Maintaining zone, you can resume training with confidence. Trying to push through the Overreaching zone is one of the most common ways injuries and burnout develop in recreational runners.
Building: Why This Zone Is Where Fitness Grows
What LODE has detected
Your recent training load is meaningfully higher than your recent baseline, but not by a dangerous margin. Your body is being challenged in a way that, combined with adequate rest, will produce genuine physiological adaptation. You're in the sweet spot of progressive overload.
Why this matters
Adaptation means stronger tendons, improved running economy, increased mitochondrial density, and better cardiovascular efficiency. It only happens when the body is exposed to a training stress it hasn't fully adapted to yet. Too little load and you maintain at best. Too much and you break down. The Building zone sits in the evidence-defined optimal band where the acute-to-chronic workload ratio indicates you are doing meaningfully more than your baseline, but not enough to spike injury risk.
LODE's EWMA model is specifically designed to detect this balance. Because EWMA weights recent activity more heavily than older training, it captures your current momentum accurately, unlike simple rolling averages that can lag behind your real fitness state. The load increase that defines the Building zone is calculated to be progressive and deliberate, not accidental or excessive.
Research by Gabbett (British Journal of Sports Medicine, 2016) established that athletes who build chronic load consistently through structured, progressive training develop the capacity to tolerate higher acute loads without the same injury risk as those with lower fitness bases. In other words: building is not just about getting fitter. It's about becoming more resilient.
What to do
Maintain your current balance of training and rest. This is not the moment to celebrate with an extra-long session or a spontaneous back-to-back hard day, doing so risks pushing you out of this zone into Overreaching. The key is consistency. Keep your rest days protected, keep your easy runs genuinely easy, and trust the process. Fitness accumulates in the Building zone over weeks, not days.
Maintaining: Why Stability Is a Feature, Not a Flaw
What LODE has detected
Your recent training load is approximately in line with what your body has been doing consistently over the past few weeks. Your load isn't growing, but it isn't declining either. You're in a state of relative stability, what sports scientists call homeostasis in the context of training adaptation.
Why this matters
Not every training week should be a building week. The Maintaining zone serves a critical purpose: it allows the structural adaptations from your recent training to consolidate. Connective tissue adaptation, particularly tendon remodelling, lags significantly behind cardiovascular and muscular adaptation. It can take weeks for tendons to structurally respond to a training stimulus. The Maintaining zone gives this process time to complete.
There's a common misconception that staying in the Maintaining zone represents wasted training time. It doesn't. A 2022 systematic review of training periodisation in elite distance runners (Casado et al., IJSPP) confirmed that the majority of elite training volume, often 70–80% across a full season, is spent at or near a stable aerobic base. The Maintaining zone is where that base is reinforced, not where it stagnates.
Maintaining also functions as the foundation from which Building is possible. If you skip too quickly from Recovering directly to aggressive Building without spending time in Maintaining, you're building on an unstable base.
What to do
Focus on running well, not running more. In the next few days, balance your sessions and rest thoughtfully to stay in this zone. If you have an upcoming long run or a planned push week, this is a good time to ensure your sleep, nutrition, and recovery are optimal, so that when you do increase load, your body is ready to adapt rather than react. If you're mid-training plan, check whether your next block calls for a build or a deload and plan accordingly.
Recovering: Why Low Load Is Sometimes the Right Load
What LODE has detected
Your recent training load is below your established baseline. Your body is in a lower-stress state relative to what it's been managing over recent weeks. This is not a failure signal. In the right context, this is exactly where you should be.
Why this matters
There are specific scenarios where the Recovering zone is precisely the goal. Deload weeks (planned reductions of 30–40% in training volume every 3–4 weeks) are a foundational tool of evidence-based periodisation. A 2024 cross-sectional survey of deloading practices in endurance athletes (Haynes et al., Sports Medicine, Open) found that practitioners most commonly implemented deload periods every 4–6 weeks, with duration of approximately one week. The purpose is to dissipate accumulated fatigue while preserving fitness, allowing supercompensation to occur before the next training block.
Similarly, if you are in the final 1–2 weeks before a target race, the Recovering zone reflects a deliberate taper. Research on tapering for endurance events consistently shows that reducing volume by 40–60% while maintaining some intensity produces peak performance, and that the chronic fitness you've built doesn't meaningfully decline in 1–2 weeks of lower load.
The key distinction is between intentional recovery and unintentional detraining. If you're in a deload week or pre-race taper, the Recovering zone is your friend. If you've been ill, missed training due to life circumstances, or haven't run in two weeks, your chronic fitness base is beginning to erode and your first run back should be cautious, with a gradual rebuild to avoid an acute spike on a now-reduced baseline.
What to do
If this is a planned deload or taper: this is good. Your body is consolidating the fitness you've built. Use this bandwidth wisely, one or two quality sessions (short, not long, with some effort) are valuable in this zone. Don't fill the extra capacity with extra volume all at once.
If this wasn't planned: treat your return to training as a fresh start. Your tissues have partially de-adapted. Build back gradually, targeting the Maintaining zone before pushing into Building. Patience here is one of the highest-return investments in long-term training.
Sources used across all four zone explanations:
Gabbett, T.J. (2016).
British Journal of Sports Medicine
, 50(5), 273–280.
Nielsen, R.O., et al. (2025).
British Journal of Sports Medicine.
DOI: 10.1136/bjsports-2024-109117
Meeusen, R., et al. (2013).
Medicine & Science in Sports & Exercise
, 45(1), 186–205.
Casado, A., et al. (2022).
IJSPP
, 17(6), 820–833.
Haynes, E.M., et al. (2024).
Sports Medicine — Open
, 10(1), 26.
Murray, N.B., et al. (2017).
British Journal of Sports Medicine
, 51(9), 749–754.
