Training Through Winter

When the clocks go back and darkness bookends your day, keeping your running consistent becomes a genuine challenge. But winter training—done right—can be the foundation for your best performances come spring and summer.

Why Winter Running Matters

The off-season is where aerobic base is built. Those steady miles in cold, dark conditions develop the mitochondrial density and capillary networks that power faster running later ^[1]. Skip winter, and you're starting from scratch when race season arrives.

Beyond physiology, there's something to be said for the mental resilience forged by heading out when every instinct says stay warm. Runners who maintain consistency through winter often find spring races feel easier by comparison.

The Vitamin D Challenge

Here's a reality UK runners face: from October to March, the sun sits too low in the sky for your skin to produce vitamin D, regardless of how much time you spend outside ^[2]. This matters more than many runners realise.

Vitamin D plays critical roles in:

• Muscle function—vitamin D receptors are present in skeletal muscle, and deficiency is associated with weakness and impaired performance ^[3].
• Bone health—it regulates calcium absorption; inadequate levels increase stress fracture risk, a nightmare injury for runners ^[4].
• Immune function—deficiency is linked to increased upper respiratory infections, which spike in winter and can derail training blocks ^[5].
• Recovery and adaptation—emerging research suggests vitamin D influences muscle repair and inflammatory response to exercise ^[6].

Studies estimate that 40–50% of UK adults have insufficient vitamin D levels during winter months ^[2]. For runners pushing their bodies through training, the stakes are higher. Public Health England recommends everyone consider supplementing with at least 10 mcg (400 IU) daily during autumn and winter, with athletes potentially benefiting from higher intakes ^[7].

RunStrong includes vegan Vitamin D3 at 10 mcg (400 IU) per serving—helping bridge the gap when sunlight can't.

Staying Healthy Through Winter

Heavy training loads temporarily suppress immune function, leaving a window of vulnerability after hard sessions ^[8]. Combine this with winter's circulating viruses, crowded indoor spaces, and reduced vitamin D, and illness becomes a real threat to consistent training.

Practical steps to stay healthy:

• Prioritise sleep—immune function drops significantly with sleep deprivation. Aim for 7–9 hours, especially during heavy training weeks.
• Fuel adequately—low energy availability suppresses immunity. Don't combine high mileage with aggressive calorie restriction.
• Manage stress—psychological stress amplifies the immunosuppressive effects of training.
• Support with nutrition—vitamin D, vitamin C, zinc, and adequate protein all contribute to immune resilience ^[9].
• Address inflammation wisely—chronic low-grade inflammation can impair immune function. Curcumin has been shown to modulate inflammatory responses and may support immune health ^[10].

Adapting Your Training

Winter isn't the time for peak performance—it's the time to build. Consider these adjustments:

1. Focus on aerobic base
   Emphasise easy and moderate running. Build volume gradually. Save the intense speedwork for when conditions improve and your base is solid ^[1].
2. Be flexible with sessions
   If conditions are dangerous—ice, heavy snow, severe wind—move the session or swap for indoor alternatives. Injury from a slip sets you back far more than one missed workout.
3. Incorporate strength work
   Winter is ideal for building the strength that protects against injury. With fewer races, you can prioritise gym sessions without worrying about residual fatigue ^[11].
4. Use the treadmill strategically
   Don't dismiss the treadmill entirely. For tempo runs, intervals, or simply when conditions are impossible, it's a valuable tool. Some runners find it useful for maintaining pace discipline.
5. Warm up thoroughly
   Cold muscles are more prone to strains. Extend your warm-up routine in winter—dynamic movements indoors before heading out, then an easier start to your run.

Gear Essentials for Dark, Cold Running

The right kit makes winter running far more tolerable:

• Visibility—reflective vest, LED lights (front and rear), bright colours. Assume drivers cannot see you.
• Layering—a moisture-wicking base layer, insulating mid-layer if very cold, and windproof/water-resistant outer. Avoid cotton, which holds moisture.
• Extremities—gloves, hat or headband, and consider a buff for face coverage on bitter days. You lose significant heat from head and hands.
• Footwear—trail shoes or those with better grip help on slippery surfaces. Some runners use traction devices for icy conditions.

Maintaining Motivation

Motivation naturally dips without races on the horizon and with challenging conditions outside. Strategies that help:

• Set a spring goal—having a target race gives purpose to winter miles.
• Run with others—accountability and social connection make dark runs far more appealing. Club runs are invaluable.
• Track your progress—log your runs. Watching consistency build is motivating in itself.
• Embrace variety—explore new routes, try trail running if you usually stick to roads, or experiment with different sessions.
• Reward yourself—sometimes the promise of a hot coffee after your run is enough.

Recovery in Winter

Cold weather can mask the need for recovery. You might feel less sore simply because of lower temperatures, but your body is still adapting and repairing.

Pay attention to recovery nutrition—don't skip post-run fuel because you're not sweating as visibly. Warm recovery drinks and meals can be both practical and appealing.

Managing inflammation remains important year-round. The combination of increased training load (base-building) and reduced vitamin D creates conditions where anti-inflammatory support is particularly valuable. RunStrong's formula—combining Curcumin C3 Complex®, Vitamin D3, L-Carnitine, and Iron Bisglycinate—is designed with year-round runner health in mind, but the vitamin D and anti-inflammatory benefits are especially relevant through the darker months.

Final Take-Home Points

• ❄️ Winter builds your base—consistent aerobic training now pays dividends in spring performance.
• ☀️ Supplement vitamin D—UK winters make it impossible to produce enough naturally. RunStrong provides 25 mcg (1000 IU) vegan D3 per serving.
• 🛡️ Protect your immune system—prioritise sleep, nutrition, and stress management to stay healthy through winter.
• 🔧 Adapt your training—focus on base, add strength work, and be flexible when conditions demand it.
• 🔦 Invest in good gear—visibility and appropriate layering make winter running safer and more enjoyable.
• 🎯 Keep a goal in sight—spring races and social running help maintain motivation.

References

1. Seiler S. (2010). What is best practice for training intensity and duration distribution? International Journal of Sports Physiology and Performance.
2. Webb AR et al. (2018). Influence of season and latitude on vitamin D synthesis. Progress in Biophysics and Molecular Biology.
3. Tomlinson PB et al. (2015). Effects of vitamin D supplementation on muscle function. Journal of Science and Medicine in Sport.
4. Lappe J et al. (2008). Vitamin D and calcium supplementation reduces stress fracture risk. Journal of Bone and Mineral Research.
5. Martineau AR et al. (2017). Vitamin D supplementation to prevent acute respiratory infections. BMJ.
6. Owens DJ et al. (2015). Vitamin D and the athlete. Sports Medicine.
7. SACN. (2016). Vitamin D and Health Report. Scientific Advisory Committee on Nutrition.
8. Nieman DC, Wentz LM. (2019). The compelling link between physical activity and the body's defense system. Journal of Sport and Health Science.
9. Walsh NP. (2019). Nutrition and athlete immune health. European Journal of Sport Science.
10. Hewlings SJ, Kalman DS. (2017). Curcumin: A review of its effects on human health. Foods.
11. Blagrove RC et al. (2018). Effects of strength training on endurance performance. Sports Medicine.

Related: Iron depletion accelerates with overtraining — read our guide to overtraining syndrome to spot the signs. If iron supplements upset your stomach, our runner's stomach guide explains why the form of iron matters.