Warm-up Before a Race: Essential or Optional?

You know the drill: you're at the starting line, bib pinned on, and around you, it's a mixed bag. Some runners have been jogging for twenty minutes, doing drills, strides… while others stroll up casually, hands in pockets, barely out of the car. Who's right? Honestly, it depends. The distance, your goal, your running profile – all of that completely changes the answer.

What's the Real Purpose of a Warm-up?

The basic idea is to get your body ready to perform from the get-go. By jogging gently, you raise your muscle temperature, increase blood flow, improve joint flexibility, and get your aerobic system engaged. The result: when the race starts, you don't need two miles to get "in the zone."

But – and this is where it gets tricky – every minute of jogging before the start means less glycogen. The same glycogen that sometimes needs to last over four hours in a marathon. Hence the importance of pacing yourself.

10K: A Warm-up Truly Makes a Difference Here

In a 10K, you start fast right from the gun. If you're aiming for 45 minutes, you're immediately at a 4:30/km pace – close to your lactate threshold. Without a warm-up, your first miles are run in an "oxygen debt": your heart struggles, muscles accumulate lactate too early, and you pay for it in the second half. Personally, I can definitely feel the difference between a 10K with and without a warm-up.

A good warm-up routine for a 10K: 10 to 15 min of easy jogging, a few dynamic drills (high knees, butt kicks, side shuffles), and 3-5 progressive strides over 80-100m. Finish this 5-10 min before the start so you don't get cold.

The other advantage is that it allows you to feel your target race pace in your legs. Feeling a 4:30 or 5:00/km pace before starting helps prevent you from going out too fast in the excitement of the first meters – a classic 10K mistake.

Marathon: The Bare Minimum Is Often Enough

For a marathon, it's a different story. You start at a pace well below your VO2 max, and the first few miles act as a natural warm-up. Someone aiming for 4 hours starts at a 5:41/km pace – no need to prep a rocket.

And most importantly, every calorie spent before the start is one less calorie for mile 22 (the 35th kilometer). Consequently, many experienced marathoners settle for 5-10 minutes of brisk walking and a few joint mobility exercises. Even elites often limit their warm-up to a short jog – far less than they would do before a 5K on the track.

Exception: If you're aiming for a fast marathon (sub-3 hours), the starting pace of 4:15/km justifies a more serious warm-up. And in cold weather, a few minutes of jogging prevents you from starting with stiff muscles.

The Mental Warm-up: Often Overlooked

Beyond the physical, a warm-up is also a ritual. It shifts you from 'normal life' mode to 'competition' mode. It creates a bubble of concentration, reduces pre-race stress, and gives you a sense of control over the situation. For some, skipping the warm-up is like going on stage without having rehearsed.

Conversely, an overly long warm-up can amplify anxiety. If your legs feel heavy during your pre-race jog, a negative spiral can quickly set in. I've experienced that myself, and it's not pleasant at all.

When Can You Skip It?

Several situations where a warm-up is optional, or even counterproductive:

• Long races without a time goal: If you're running a marathon or trail race for enjoyment, the first few easy miles will do the trick.
• Extreme heat: At 86°F (30°C) and above, every extra minute of effort accelerates dehydration. It's better to stay in the shade.
• Logistical hassles: At some races, the corrals close early, bag drop-off is far away, and there's no room to jog. It's better to be well-positioned in the corral than well-warmed up 500m from the start.
• Long-distance beginners: If your goal is just to finish a half marathon, a few minutes of walking and mobility exercises are more than enough.

An Adaptable Routine

Rather than a rigid plan, adapt your warm-up to the situation:

• 5K / 10K race: 10-15 min jog + drills + 4-5 progressive strides.
• Half marathon: 8-10 min light jog + 2-3 short strides.
• Marathon: 5-10 min brisk walk or very slow jog + joint mobility exercises.
• Trail / ultra: 5 min active walk, possibly a few squats and lunges.

In any case, your warm-up should never make you tired. If you're already sweating profusely before the start of a marathon, you've probably done too much.