Spring Training Ramp-Up: The Most Common Mistakes Endurance Athletes Make

Bike rider in the snow fat tire bike

Spring is when training really starts to pick up! The weather improves. Race calendars fill up. Long rides get longer. Weekend runs stretch out. Group sessions start again. For most endurance athletes, this is the time of year when volume and intensity ramp up and it’s also when we start seeing more injuries walk through our doors at Progressive Physical Therapy.


If you’ve ever felt great in early spring only to be sidelined a few weeks later, you’re not alone. The issue usually isn’t motivation. It’s how the training cycle is structured.

Here are the most common mistakes endurance athletes make and how to fix them!


  • A lot of athletes train at a moderate effort most of the time. Not easy. Not truly hard. Just kind of “steady.” The problem? That middle zone creates fatigue without maximizing adaptation. Many successful endurance athletes structure their training with a large percentage of low-intensity work, a smaller amount of high-intensity work, and very little time spent in that moderate gray zone.

    When every workout feels “kind of hard,” recovery suffers and performance stalls.

    Clinic Takeaway:
    Make your easy days truly easy. Make your hard days purposeful. Stop racing every workout!

  • When spring hits, many athletes jump straight into intervals and speed work. But aerobic base training builds the foundation. It improves your body’s ability to use oxygen efficiently and tolerate higher workloads later in the season. Without that base, high-intensity work has less return and higher injury risk. You can’t shortcut physiology!

    Clinic Takeaway:
    Build volume gradually before layering intensity. Aerobic capacity supports everything that comes later.

  • This is one of the biggest mistakes we see. As weekly mileage climbs, strength training is often the first thing cut.

    But strength training:

    • Improves running economy

    • Improves cycling performance

    • Increases tendon stiffness

    • Builds tissue resilience

    • Reduces injury risk

    Endurance athletes who maintain strength training tend to be more durable across long seasons.

    Clinic Takeaway:
    Strength isn’t optional for endurance athletes. Two focused sessions per week can significantly improve durability without compromising endurance gains.

  • Spring motivation is powerful. Longer days. Better weather. Bigger goals. It’s easy to go from “winter base” to stacking long runs, big vert days, and intensity all in the same few weeks. But this is where we see the majority of spring injuries.

    You’ve probably heard of the 10% rule: increasing your training load by no more than about 10% per week. While it’s not a perfect formula, it’s a helpful guardrail for managing progression. And it applies to more than just mileage.

    The 10% Rule and Mileage

    If you ran 20 miles last week and jump to 30 miles this week, that’s a 50% increase — even if it feels manageable aerobically. Your heart and lungs may adapt quickly. Your tendons, joints, and connective tissue do not.

    A gradual progression (for example, 20 → 22 → 24 miles) allows tissues to remodel and strengthen instead of becoming irritated.

    The 10% Rule and Vertical Gain

    For trail runners, hikers, ski mountaineers, and cyclists, vertical gain matters just as much as mileage. If you normally accumulate 2,000 feet of climbing per week and suddenly jump to 6,000 feet, that’s a massive spike in mechanical stress — especially on:

    • Calves and Achilles

    • Patellar tendons

    • Quads (particularly downhill running)

    • Hip stabilizers

    Vert is not “free fitness.” It’s added load. We frequently see athletes increase mileage modestly while dramatically increasing vert — and tendon flare-ups follow quickly.

    The Bigger Picture

    The 10% rule isn’t rigid. Some athletes tolerate more. Some need less. But the principle remains:

    Avoid sharp spikes in total workload.

    And remember:

    • Mileage increases count

    • Vertical gain increases count

    • Adding intensity counts

    • Adding frequency counts

    If you increase mileage, vert, and intensity all in the same week, you’ve multiplied the stress even if each change seems small individually.

    Clinic Takeaway:
    Track both mileage and vert. Progress gradually. Your lungs may feel ready — your tendons may not be.

  • When training volume increases, your fueling needs increase too. This is one of the most overlooked reasons endurance athletes plateau or get hurt in the spring. Under-fueling affects recovery, hormones, bone health, tendon resilience, sleep, and overall performance. We often see athletes who are training consistently, but not eating enough to support it. You can’t recover from work you don’t fuel.

    So What Does “Enough” Look Like?

    You don’t need to count every gram, but here are some simple guidelines:

    • As training ramps up, your carbohydrate intake should increase too. Long runs, hard intervals, and big vert days require carbs

    • Include protein at every meal to support muscle and tendon repair

    • If you’re training most days of the week, eating like it’s a rest week won’t cut it


    During Longer Sessions

    If you’re training longer than about 60–90 minutes:

    • Bring fuel

    • Most athletes benefit from taking in carbohydrates every hour during long runs or rides

    • Waiting until you’re exhausted or lightheaded is too late

    Proper fueling during training improves recovery the next day and helps prevent digging a hole you can’t climb out of.

    A Simple Self-Check

    If you’re noticing:

    • Persistent fatigue

    • Declining performance

    • Trouble sleeping

    • Irritability

    • Unintentional weight loss

    • Recurring bone or tendon issues

    …it might not be overtraining. It might be under-fueling!

    Clinic Takeaway:
    When training goes up, nutrition needs to go up. Adaptation doesn’t happen in a deficit.

  • Performance improves during recovery — not during training itself. Without planned recovery blocks, athletes risk burnout, plateau, and chronic irritation.

    A proper transition phase allows:

    • Tendon remodeling

    • Nervous system recovery

    • Mental reset

    • Long-term durability

    Clinic Takeaway:
    Longevity beats a short-lived peak. Build recovery into your yearly plan.


The Big Picture

Endurance performance is cyclical.

Base → Build → Peak → Recover → Repeat

Problems arise when phases blur together or get skipped entirely. The goal isn’t to train harder. It’s to train intelligently. Spring training should set you up for a strong season, not sideline you before it begins.


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If spring training has you dealing with:

  • Recurring running injuries

  • Persistent Achilles or patellar tendon pain

  • Plateaued cycling power

  • Hip, knee, or low back discomfort

  • Fatigue that doesn’t match your workload

It might not be about pushing more. It might be about optimizing the details! We work with endurance athletes to improve performance and reduce injury risk.


We offer:

Running Gait Analysis
To identify inefficiencies and loading patterns that may be limiting performance or driving pain.

Individualized Strength Programs
Designed to improve durability, economy, and long-term resilience.


If you’re ramping up training this spring and want to make sure your body keeps up with your goals, reach out to usin Anchorage and the Valley to schedule a visit.

Your training should build you up — not break you down.


this blog post was written by Coleman Ahrens, PT, DPT

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