Every Training Zone Explained, With the Best Sessions

Get Fast Podcast, Ep 125, with Gerard and Jordan Donnelly

Every zone model is built around two turning points: the first lactate threshold (LT1) and the second (LT2). TriVelo uses six zones. Zones 1 and 2 sit below LT1, zones 3 and 4 sit between LT1 and LT2, and zones 5 and 6 sit above LT2. Coaches use different names and slightly different numbers, but the meaning of each zone is much the same.

They're clear this is TriVelo's own interpretation, and other coaches will have their own variations.

What are LT1 and LT2?

The simplest version is three zones: easy, medium and hard.

• Below LT1 (easy): also called the aerobic threshold. If you're fit and fuelled you could keep going all day, and you could hold a conversation. Lactate isn't building up.
• Between LT1 and LT2 (medium): you feel like you're working and lactate starts to build, but you can keep going for a long time.
• Above LT2 (hard): also called the anaerobic threshold, or FTP on the bike. Lactate builds quickly, and the further above it you go, the shorter you can hold it.

In plain words: "I can keep doing this all day", "I can keep doing this for a long time but it's getting hard", or "I can't sustain this for very long".

Here, intensity means the level you're aiming for, so a recovery ride has an intensity too.

Zone 1: what is active recovery for?

Active recovery gets blood flowing to the muscles to repair the damage from the last few hard days, with no aim of improving fitness. You shouldn't be sweating, and grandma could be riding past you. The shorter the session, the better.

It has one more benefit. It gets your body used to a training load without adding intensity it isn't ready for, which matters most in running, where loading up too quickly raises the risk of injury. Walking counts. Gerard is a cyclist who can't run, and he walks for recovery.

Zone 2: why does such an easy zone matter so much?

Zone 2 runs from just above recovery up to LT1. Gerard compares it to the accountant everyone calls boring but can't do without. The fitter you are aerobically, the better you handle the hard sessions, so outside of your hard and race-specific sessions, this is where most of your training should sit, in all three sports.

Where you sit in the zone changes from day to day:

• The best case is an athlete with a big base who can do all their zone 2 work near the top, just under LT1, without it hurting their hard sessions.
• Most people start nearer the bottom of the zone.
• If zone 2 work stops you doing your high-intensity sessions well, pull it back.

After a brutal Tuesday session, Jordan let Gerard go early on a Wednesday zone 2 ride and stayed at the bottom of the zone. A week later, fresher, he rode at the top of it.

Heart rate and feel help here. If the same power brings a heart rate 10 beats higher because of a hard session the day before or a bad night's sleep, drop back. On the other side, holding the same heart rate at a higher power or a faster pace shows you're getting fitter.

Runners can't do as much long zone 2 work as riders, especially if they're new to running.

Zone 3: where does tempo fit?

Gerard calls tempo the lost soul. It's the zone TriVelo spends the least time in on purpose. You'll drift into it on hills and in bunch rides, and that's fine for short periods.

It matters more for some race preparation. Depending on ability, some Ironman and half Ironman athletes spend race day in tempo, so their race-specific sessions mix zones 2 and 3. The same goes for riders preparing for Peaks, the Australian gran fondo over Tawonga Gap, Mount Hotham and Falls Creek.

Zone 4: what is sub-threshold training?

Zone 4 is sub-threshold, or sweet spot: anything up to just below LT2. Many five-zone models stretch this zone to just over threshold. TriVelo's stops below LT2 on purpose.

This is the go-to race zone for most 70.3 athletes, and for some Olympic distance athletes. It's done in long blocks with recovery between them, so you stay in the zone instead of fading into zone 3. You have to build into it, the same way a runner builds on flat ground before hill work. It won't leave you out of breath, but it's grueling: "you're getting a toothache in your legs."

Zones 5 and 6: why train above threshold?

Zone 5 is threshold and a little above. Zone 6 is the very top end, VO2 max. The line between them is blurry, and time decides the session. Closer to threshold means longer intervals, such as 3 x 8 minutes. Higher means shorter ones, such as 5 x 3 minutes.

There are two reasons to train here: it replicates parts of your race, and it's the way to improve. If you want to get better, some work above LT2 has to be in your program.

Prepare for these sessions:

• Know what you did last time. If you ran your 1km intervals at 4:15 pace last week, starting at 4:28 because the plan says 4:15 to 4:30 wastes the session.
• If you go so hard that you can't finish a 4 x 4 minute set, you'd have been better off dropping the power and completing all four, then building from there the next week.

How do you choose which zones to train in?

Start from your event and work backwards. A criterium, a gran fondo, an Olympic distance triathlon, a 70.3 and an Ironman each spend race day in different zones.

Related

• How we coach triathletes
• Cycling coaching
• Running coaching
• About Gerard Donnelly