With the onslaught of technology and gadgets to help you go faster, the most commonly asked question among the athletes I work with is still, “What heart rate should I race at in my IRONMAN?”
The average IRONMAN finisher, who’s going to be out on course for 12-plus hours, should be sustaining an effort they can maintain for the entire race. There’s no advantage to swimming at tempo or threshold effort, biking as hard as you can, and walking the marathon. (Unless that’s your race plan due to injury or lack of training.) If this has been you on race day, and that wasn’t the plan, I’ve got the solution to your problem: slow down.
Easier said than done, I know, but with a little help from that coach on your wrist and strap around your chest, you should be able to execute a well-thought-out plan.
While I’m a firm believer in training all your heart rate and power zones from VO2 all the way down to easy aerobic workouts, on race day you should fall into to the zone that will keep you moving along at a respectable pace while maintaining a heart rate you can hold for 140.6 miles. Even though you should be training across all zones for an IRONMAN, the majority of your time should be spent in the “all day effort” of the aerobic zone. Below I’ll address this zone for each sport, with steps on figuring out yours.
Swim testing for IRONMAN
Open water swimming is very different than pool swimming due to having to sight (aka see where you’re going), deal with the sun, potential chop, and currents. The one piece of advice I repeat over and over is to get in the open water as often as possible and learn to become comfortable with these issues. More than anything, swimming well in open water is about experience.
With that being said, my swim test is based off a long straight swim of at least 1,500 to 2,500 yards. The swim test should take you at least 30 minutes, or more. This swim should be done as a ‘best effort’ for the time/ distance you choose. Try to swim the pace evenly, but at the same time you should try to swim it as fast as you can. If possible try to swim the same distance in the water to see the difference in your pace.
Knowing what your pool pace is per 100 yards is important—see how it compares it to your open water pace. (Wearing a wetsuit and how straight you swim will affect the results—this is why I mention practicing in the open water as much as you can.) Also, understanding your effort and breathing pattern in the pool during these long tests can be transferred to the open water. I continually ask myself when in a longer race, “Is my breathing OK? Am I going too hard?” If I feel that I’m pushing hard, I back off and let my breathing settle down. Don’t be afraid to try these ideas out in the open water before race day.
Bike and run testing for IRONMAN
For the bike and the run, I like to use a 30-minute threshold test to set the heart rate zones for the bike and run. Although this test is painful and will cause anxiety, as my athletes have told me countless times, so is racing. And if you prepare yourself in training for race day, you increase your chances for success. It’s the old adage: Practice like you want to play. In endurance sports it becomes “train like you want to race.”
How the test works: First, make sure you have a few easier training days before the test days—not complete days off, however. After a standard 15 to 20 minute warm up, you’ll perform a few pick-ups, or efforts, in the 90 to 95 percent effort range. These can be 30-second efforts on the run, or up to 90 seconds on the bike. Once you feel that you’ve warmed up the legs and the mind, you’re ready to start the test.
The idea here is to go as hard as you can for 30 minutes. If it’s easier to run a certain distance, knowing you can cover, say, four miles in 30 minutes on the run, or 11.5 miles for the bike, then that’s fine as well. Just finish the test knowing you couldn’t have gone another minute at that effort. Recruiting training partners to pace you is fine or jumping into a local 10k run race or bike time trial will work fine, as long as you are out there for at least 30 minutes.
Once you have your average heart rate for the respective tests, you can then use the heart rate calculator on Training Peaks, or the charts in The Triathlete’s Training Bible. (The IRONMAN U curriculum also provides an intensity chart with a number of different types of measures that an athlete/coach can use to determine their training zones.) For the purpose of this article, let’s say you did both tests and your average heart rate for cycling was 165 and for the run test your average heart rate was 178. This would put your estimated zones in the following ranges:
Zone 1: under 136 – under 83% of your average heart rate.
Zone 2: between 137-147 – between 83-89% of your average heart rate.
Zone 3: between 148-154 – between 90-93% of your average heart rate.
Zone 4: between 155-164 – between 94-99% of your average heart rate.
Zone 5: between 165+ – Over 99% of your average heart rate.
Zone 1: under 151 – under 85% of your average heart rate.
Zone 2: between 152-161 – between 85-90% of your average heart rate.
Zone 3: between 162-170 – between 91-95% of your average heart rate.
Zone 4: between 171-177 – between 96-99% of your average heart rate.
Zone 5: between 178+ – Over 99% of your average heart rate.
A few quick tips:
1. Always perform the tests in the order of swim, bike and run.
2. Give yourself an easy day between the bike and run tests.
2. Make sure you stop lifting weights the week of the test.
3. Typically, your heart rate for your run test will be about eight to 15 beats higher then your bike heart rate. For the most part this is because when you’re on a bike your weight is supported.
4. Some people like to test at the end of a rest week, whereas I like to test during a normal training week, with a few easy days beforehand, versus an entire easy week.
5. Athletes can test every 4-6 weeks and even do a race simulation or two where they swim two to three km straight, ride 100-110 miles, and run 10 miles.
While training for IRONMAN, the majority of our time should be spent in Zone 2. This is considered the aerobic or “all day” zone. The pace is conversational and you should literally be able to do it all day. At lower heart rates we are tapping into the biggest resource we have for energy: fat. And who doesn’t want to burn a little fat when training? When we are above Zone 2 we are still burning fat, but less of it. We tap more into a limited supply of energy: glycogen. This fuel source could last two to three hours, but if you deplete your glycogen stores that’s when you are at risk of bonking. Keep in mind that fat is pretty much limitless, whereas glycogen is not. In an IRONMAN race, this is the same zone you’ll be racing in. It’s hard for an athlete to wrap their head around it, but an IRONMAN bike ride shouldn’t be ‘hard’ (Keep in mind the 26.2 miles you’ll run after you get off the bike!) And is this the zone we want to be in while racing, too? You say for training, but also for racing, I’m assuming? The Zone 3 efforts for IRONMAN should be reserved for athletes who are racing for placement in their age group or for any athlete who is pushing the efforts in the final miles of the run (if the rest of their race has been paced correctly).
While working with a new program can be daunting and you may even slow down a bit until your body becomes familiar with training at the proper heart rate zones, it will pay off. Be patient and give it some time. Learning to dial in your Zone 2 heart rate will help you keep the appropriate pace during an IRONMAN, and also help you better digest your race day nutrition. The harder you go in any race, no matter the distance, the harder it is to get calories down and to keep them down.
I know how boring these 30 minutes tests are, but training isn’t always about the sexy workouts. It’s the blue-collar workouts, where you put your hard hat on and just get the job done, week after week. Think of these tests as in that category of workout that need to get done every few weeks. The more you can benchmark your progress and dial in that race-day heart rate, the better you’ll race on the big day.
Mike Ricci is the owner and founder of the D3 Multisport coaching group.