TW Relay Team: James’s Run Blog #6

The only reason a man should ever shave his chest.

With one week left until my running leg of the Hyde Park Triathlon, I visited Bupa's London branch for a fitness assessment. The aim? To find out if I've got the potential to run a sub 20-minute 5K at my current level of fitness and if not, then how I can get there.

That's not an easy task for a fitness advisor; to try and relate aerobic capacity to a distinct performance. While aerobic fitness (or VO₂ max) is a good indicator of physical fitness, it's not necessarily a suitable predictor when race times are concerned. But because 5K races are so short (and generally run at a higher intensity), the race is run at a pretty high percentage of VO₂. And according to a calculator at, I'd need a VO₂ max of at least 49.9.

So, down to the assessment. After a few routine checks (height, weight, body fat percentage, blood pressure, etc) I was hooked up to an ECG and plonked on a treadmill. If you have a very hairy chest, like me, be prepared to leave the facility looking like Steve Carrell in 40-Year Old Virgin. No, they don't wax but fair chunks of chest hair will have to be removed in order for the electrodes to stick. The treadmill then runs at increments until you reach 85% of your predicted maximum heart rate, all the while taking blood pressure readings. It looks incredibly uncomfortable from the photo, but actually, the hardest part is trying to keep the mouthpiece in without drooling consistently down your front.

As well as calculating my VO₂ max they're also tracking your anaerobic threshold, the exercise intensity at which you start to work anaerobically (without oxygen) and accumulate lactic acid. More importantly though is the stage where your body produces lactic acid at a greater rate than its clearance. It's at this point that you start to become less efficient with your exercise.

After about 15 mins or so of running the results were in. In a nutshell I've got a massive lung capacity but a relatively low FEV1, which is the force of air exhaled in the first second (hardly surprising for someone who used to smoke and had asthma as a child). BMI, normal. Body fat percentage, normal. Waist-height ratio, normal but approaching the top end of the scale (translation: cut back on the beer). But the surprise result was my VO₂ max of 52.90, which puts me (just) in the superior category for my age group! Again, this is no indication of a reflective race time of well under a 20-minute 5K. A chap in my office has a lower VO₂ max than me and consistently outruns me every week.

But what was interesting was the point where I hit my anaerobic threshold. This happened when I hit 145 bpm (a 9.6 min/mile pace or That sounds quite slow to me, but could go a long way to explaining as to why I've struggled to break a sub 4-hour marathon in the past. So to improve on this, any training (hill, tempo or interval session) should be done at above this heart rate.

The whole appointment was broken down into a lengthy report, and because I'd explained what I was hoping to get out of the session I was provided with a full page explaining the information and how I can transform my training to help me reach my goal (along with advice on daily fluid consumption). The only downside is that's it's too late to do anything about it! But nevertheless, it is a bit of a confidence booster and a great excuse to play #bupatoptrumps with a work colleague! I might not break 20 minutes on Saturday, but I'll be giving it a bloody good go!

Bupa Fitness assessments are available here from £149.