Warmup

The value of a good warmup is often underestimated, especially in longer endurance events. A warmup is the gradual transition from being at rest to the required exercise intensity. If we go from standing to running at race pace, our oxygen delivery will lag behind our oxygen consumption as our Heart Rate gradually increases, causing an oxygen debt (see image below). This oxygen debt can be disruptive to our aerobic systems and impair performance. This rate of change of oxygen delivery is called V̇O₂ Kinetics. The warmup period also allows a gradual increase in muscle temperature, an increase in the oxidative enzyme activity, greater blood flow, and improved availability of fuel in a form that is usable by the muscles and improved Muscle Recruitment. It is only after this warm up that our bodies are ready to perform optimally.

A graph of V̇O₂ Kinetics when going from rest to high intensity exercise.

Contents

1 Warmup activities

There are various activities you can incorporate into your warmup routine. The order listed is the approximate order of execution.

• Massage. Some gentle Massage, such as The Stick, can help passively warmup the muscles, as well is detecting any potential problems before the workout begins. The psychological benefits of this gentle Massage should not be underestimated, especially before an important race.
• Air squats. If you need to warmup where there is limited room, such as at the start of a crowded race, or indoors on a cold day, then air squats can be quite effective. To perform air squats (Google for a video):
  • Stand with your feet shoulder width apart.
  • Bend at the knee, slowly lowering your body until your knee is at about a 90° angle.
  • Return to the upright position slowly.
  • Repeat a few times until you start to feel warmed up. Anywhere from 5 to 20 repetitions is probably appropriate.
• Walking. You can use walking is a more gentle introduction to your workout. Walking for a couple of hundred yards/meters can ease the transition from resting to running.
• Slow running. The initial running should be at a fairly gentle pace and build up gradually. How long can you need to spend building up the pace will depend on your target intensity. If you're intending to run at an easy pace, then the buildup may only need to be half a mile or so. At the other extreme, if you're intending to do High Intensity Interval Training, then you may need to build up over 3 or 4 miles, with a final pace being reasonably fast (around 10K pace).
• Stretching. If you want to Stretch do so after the warmup, to reduce the risk of injury. Stretching briefly weakens the stretched muscle, so if you need to increase your range of motion, it's probably best to stretch after your training. See Stretching for more details.
• Plyometrics. Plyometrics are short explosive exercises, and they tend to improve the Muscle Recruitment as well as building strength. Plyometrics have been shown to improve Running Economy, probably through the changes in Muscle Recruitment. Because of the short intense nature of plyometrics they should be done at the end of the main warmup. I would recommend some simple jumps, starting as a gentle bouncing and building up to a moderate intensity. The video below shows some simple air squats followed by plyometrics.

2 Warming up for short races

For races less than the marathon distance it is best to warmup before the race starts. The intensity of the warm up must be high enough to increase blood flow to the muscles, raise blood fuel, activate enzymes, etc., so slow jogging is not terribly effective. The optimal strategy would appear to be to start slowly and build up to about 10K pace. Some dynamic stretching could be included after the initial slower start of the warmup, but remember that stretching temporarily weakens the stretched muscles. The warmup needs to finish just a few minutes before the race starts; too close to the race and you won't be recovered from the warmup, but too long and you will have lost the benefits. When Running in the Heat, it may help do use Precooling.

3 Warming up for the marathon

Warming up for the marathon is rather trickier than other races. One critical limiting factor for marathon racing is the supply of Glycogen, so any warmup that uses Glycogen may impair performance. For most runners therefore the optimal approach is to use the first mile as a warmup. This means starting slower and building up to race pace over the first few minutes. For faster runners (sub three hour) there may be some advantage to a warmup before the race commences but this is a balance between being a faster in the first mile and possibly hitting the wall at the end of the race. Some gentle dynamic stretching can be included before the race to help speed up the warmup process without significant Glycogen depletion, but care must be taken to avoid overstretching injuries.

4 Warming up in ultramarathons

For all but the fastest runners in shorter ultramarathons, the best approach is to warmup over the first mile. Even with the 50K races, the impact of a slightly slower start on overall race times is likely to be minimal. (I've finished in second place in a 50K, just seconds behind the winner, but I'm convinced that going out faster in the beginning would've made me slower overall.) Some dynamic stretching can be included before the race, but the slower pace of ultramarathons makes this less critical.

5 Warmup and Injury

There's lots of research into warmup, Stretching and injury prevention, but the quality is often quite poor. A meta-analysis of the research into stretching and injury found only 7 of 364 studies met their criteria, and found moderate to strong evidence that stretching does not reduce overall injury rates, but might reduce tendon injuries. I found one review of the research that found there was good evidence supporting the rationale that warmup should reduce injury. For instance, it argued that warmer muscles are less viscus, and therefore might be less injury prone, but it didn't look at injury rates directly. Another study counter-argued that because a warm up allows greater force production, faster contraction speed, and greater stretch, the risk of injury is actually greater, though again, it only used rationale, not experimental data. A review found a warmup that included "stretching, strengthening, balance exercises, sports-specific agility drills and landing techniques" reduced injury over three months in various athletes and military recruits. An analysis of five random controlled trials found some evidence to suggest a warm up might reduce injury risk, though a running specific study found no benefit from warmup/stretching. My suspicion is that a warmup may help with certain types of activity, such as football, more than running. It's possible that a warmup may help before high intensity running, though none of the research I found tried warmups for specific training modalities. I believe that sports like cycling are least likely to have an injury reduction from warmup due to the constrained range of motion.