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(Pocket-lint) - The Suunto t3c Black Arrow edition is a special edition release of its t3c model or heart rate monitor, partnered with the International Triathlon Union. Featuring a standard heart rate monitor when used with the provided chest strap, it takes the fight to Polar, the market leaders for this type of device.

The watch itself is relatively compact, freed from the bloat of devices that also contain a GPS unit. The Black Arrow edition is so named because of the livery it adopts: black bodywork and face is partnered with red numbers around the bezel, giving it an edgy masculine look. The watch itself feels pretty well-built, with a nice solid metal back, but the strap does feel a little soft and flimsy.

The display itself chooses to put white information over a blacked out background, rather than the more common black on white. It's a design decision that makes the Black Arrow look good, but it means that overall it is more difficult to read than a conventional approach.

Given the circular space available for the display, it isn't very well used overall, with plenty of empty corners. Curving the text slightly might have allowed a larger digit display to make it more legible on the run.

The bezel ring that features the red numbers perhaps looks a little cheap and they are rather small to glance at on the move. The bezel is divided into heart rate running clockwise and training zones (which Suunto is calling training effect, more on which later) running anti-clockwise.

The chest strap is comfortable, with a large central transmitter. It perhaps isn't as impressive as Polar's WearLink straps, but is better than some of the plastic and rubber straps out there. The connection, however, was solid and we never found a problem detecting the signal or holding on to it for the duration of the exercise.

The watch features five buttons which are large knurled ends so have plenty of grip for pressing with sweaty fingers.

Essentially there are two modes – clock or training. The clock mode gives you access to your training log, which will present you with a graphical representation of your exercise based on Suunto's Training Effect (TE) scale, and cycling through to give you a breakdown of your stats: average and max heart rates, exercise duration, calories burned and finally the TE level.

Training Effect is the value-added feature here and moves the Black Arrow from a basic heart rate monitor to one that gives you a little pointer as to the results your training will achieve. The 1-5 scale runs from "Minor" to "Over-reaching" (fitting loosely with the science behind 5-point zone training outlined in Joe Friel's The Triathlete's Training Bible).

The idea here is that you can either set yourself a zone yourself (based on what you want to achieve), or just head out and see what you get to. As you set off the zone is low and slowly builds as the overall effect of your training becomes apparent. It gives you good definition over training intensity, although for those training by heart rate may choose to ignore it completely and just watch their average HR.

You also get a more conventional heart rate zone training option. This gives you three zones, with alarms, so you can opt for train in any of the zones depending on whether you want a threshold session, or are on a recovery session.

You can also schedule intervals, with two available where you can define the duration of each interval. There is also a warm-up option, so you can force yourself to do a 5- or 10-minute warm-up on each session, with a neat countdown timer for these options.

This effectively rounds out the features that are available on the core watch, although you can expand the system further by opting for the accessory PODs. This will let you add GPS, cadence for your bike or a foot POD, as well as the PC POD so you can download your training data. Without these, however, extracting your data isn't possible.

Despite the partnership with the ITU, as it is the Suunto t3c Black Arrow doesn't have any special triathlon features, like a multisport mode for example. However triathletes might like the options presented to expand the system to cover their bike training too.


In practice the Suunto 3tc Black Arrow works well, but we'd question the colour scheme here – the screen isn't the clearest, so one of the more conventional displays might be better.

We have no qualms with the range of features available either. If you have an established training programme then there is just about the right amount of flexibility here to help you target the right training intensity. You can also scroll through your display options in training, so you can display exercise duration and the real time, which provides plenty of flexibility to see the information you want.

But at £120 it comes in above some of the entry-level devices out there, so if you have no plans to take advantage of the POD expansion in the future, you might be able to save some cash by opting for one of the rivals.

Writing by Chris Hall.