This is the first in a two part series on the practicalities of a
personal VO2 Max performance assesment session. Magicalia staffer
Jeremy went to meet Peter Byworth of VO2forTRI.com and rode to exhaustion whilst breathing through a gas exchange measurement mask
and strapped up to heart rate recording equipment. This first article explores what you can expect from such a session. It will be followed by an article by the performance coach conducting the test, Peter Byworth, who will feed back the results of the session.

RoadCyclingUK.com has also negotiated a special package for readers
who might be interested in testing their own base line performance and getting a similarly tailored training programme. Read on for more details…

“That’s another fine mess you’ve got me into, Stanley…”

I was out for dinner with a friend, Bruno, when conversation turned to his impending TransAlp challenge. Like me, Bruno has two young
babies, so I asked how he could possibly squeeze in enough training. His response was interesting; he had made a big effort to ensure every session he rode had the absolute maximum benefit, not that he was trying to beg, borrow or steal more time in the saddle.

Bruno also explained that the foundation for his new training outlook had been a performance assessment session where they had tailor recommended his personal heart rate training zones and training balances. I had heard about VO2 max assessment sessions before and was aware of the basic principles. However, Bruno was very compelling on just how insightful the session had been and how it had changed his outlook on his limited training programme. The next day I found myself on the phone…

“What’s involved”

The full session takes about two hours and is divided across two tests. The first measures “Resting Metabolic Rate (RMR)” and the second is the ‘full bike ride to exhaustion’, measuring a series of breathed gas, heart rate and power output readings along the way.
The two key measurements which result are VO2 Max and Lactate Threshold, but the real benefit of the session is a tailored set of training zones and recommendations for training plans and techniques to get the most out of your time on the bike.

But, before all that kicks off, Peter greets you with an introduction to the session and an explanation of its aims. The session is held at the “SwimForTri” centre at Truman Brewery in the East End of London. The facilities are great, a reception, changing room and showers, (a video / mirror pool if you’re looking for triathlon training tips), and a bike / running treadmill for the VO2 max tests.

Peter sat me down and explained that this was not a competition nor a measure of strength / stamina. Most averagely fit cyclists bring their competitive instincts to the session and these preconceptions aren’t helpful. It’s not really intended for measuring your output so much as for finding your baseline metabolic and aerobic fitness
characteristics in order to tailor a more *effective* set of training conditions.

“The Science behind it…”

Next Peter asked a detailed series of questions about lifestyle, current training programmes, aims etc. He explained the measurements that would come out of the tests:

(1)Resting Metabolic Rate (RMR); used to help compute the number of
calories you need to consume to maintain your current weight given your current activity level.

(2)VO2 Max; which indicates the volume of oxygen your cardiovascular system can absorb per minute, divided by your weight, is a sort of measure of the “horsepower in your engine”. There’s not a lot you can do to train this “raw horsepower”, instead Peter likened muscle and cardiovascular training to “tuning” the engine to use that horsepower more effectively, and you can of course lose weight to up your VO2 Max (more horsepower per kilo of car, I guess!).

(3)Lactate Threshold; by measuring the point at which exhaled CO2 jumps, it is possible to measure the exertion level at which the body switches from burning fat as the muscles’ primary source of energy to consuming carbohydrates and glycogen stored in the muscles.
This point is critical for training purposes. Operating anaerobically above this “lactate threshold”, the body is producing lactic acid at a rate it can’t process as quickly as it is created. The body is effectively operating on borrowed time.

This measure also enables the performance coach to construct a “fat burning curve” and to calculate the target heart rates for optimal fat burn, and indeed rates and programmes designed to increase this lactate threshold. Unlike the VO2 Max measure, this threshold is very trainable and, using our earlier analogy, is akin to the “engine’s state of tuning”.

“…and the Test Itself”

The test starts off tamely enough – 15 minutes sat calmly in a comfy
sofa, breathing gently into the gas exchange measurement mask. This establishes a baseline and enables the RMR calculations.

Then onto the bike – a kind of spinning bike fitted with proper handlebars and saddle and decked out with your own pedals. The test is simple enough; 5 minutes of gentle pedalling to warm up, then moving into riding with gentle pressure on the pedals. Every couple of minutes Peter would ask how the exertion felt; “effort out of 10, where 10 is everything you’ve got”. Then he would wind a bit more resistance onto the bike. All the while you try to maintain steady cadence, and note your heart rate steadily climbing.

The computer bleeps away in the background sampling your oxygen and CO2 in and out, and noting your heart rate and power output, leaving seemingly nothing off the charts it plots. The test ramps up very smoothly, though clearly it ends in tears as you pass “7/10”, “8/10”, “9/10” and then stand up for a flat out sprint to the line. All the while the ordinarily unflappable Peter yells encouragement from the sidelines.

Finally, when you’ve given everything, (and the computer has noted your max heart rate safely tested), you collapse onto the handlebars for a gentle spin to warm down. And following a shower and 20 mins to recover, Peter sits down to share the results and some tailored training recommendations. I’ll leave him to pick up the tale and recount those in the following article…