I took a VO2Max test and DEXA scan recently and compared to my results from the same tests 6 moths ago. The tests give me an overall view of how my fitness and body composition has changed over the 6 months and to check that my progress is on track.
My previous results can be found here.
My VO2Max test
The VO2Max test should give an accurate view of my aerobic and anaerobic thresholds. Which in turn helps define my optimum heart rate zones for training. This will allow me to understand if I can push my effort and heart rate without compromising my fueling needs. Or risking blowing up and running out of energy.
As before the test was carried out on a Watt Bike, I wore a max that measure the oxygen in and CO2 out. This test equipment then compares these to your heart rate to provide your aerobic and anaerobic thresholds.
Aerobic and anaerobic threshold levels
You can hopefully see from the graphs above that the point where the carbon dioxide increases over the oxygen. Where the red line crosses the green line. This happens much later in the June test. and at a higher heart rate. This means that my anaerobic threshold has increased (from a heart rate of 135 to a heart rate of 151).
From this measure, your zone 2 training zone can be established. From this test my heart rate zones were established as:
On the diagram above you can see that the test has set my Zone 2 training zone as 112 to 122 bpm. This is a change from 115 to 125, but the machine has not captured my anaerobic threshold (even though it’s clear on the previous graph) but more importantly the chart shows that I’m pushing out more power for the same effort .
I.m not fully confident in the zones above but am confident for the same effort levels I’m able to push out more power.
Fat Burning
The key item to understand from the VO2Max test is my fat burning capabilities at different heart rates. The diagram below shows the calories from fat in purple and calories from carbs in yellow. You can see that even at very low levels I am using a high proportion of carbs. This was quite a big surprise, I have done a lot of zone 2 training last year, and therefore assumed that my fat burning would be well adapted.
The above graphs are the most interesting for me. In December I was burning very little fat when exercising, even at low intensities. The big change in the recent test is that I’m burning fat through a much wider range, in line with the increase in my anaerobic threshold. At lower intensities I’m burning much higher proportion and volume of fat. This is ideal for endurance events, as it means I can go for longer without fueling on carbs as I’m using my body’s fat stores for fuel.
This really brings to life the benefits of Zone 2 training for the last 6 months. Showing my fat buring range and volume to have increased. The hypothesis here is that my body has adapted by increasing mitochondria capacity, increasing my capacity to oxidise fat.
VO2Max
Another key thing for me to understand was my VO2Max. Whilst this isn’t an indicator for Zone 2, it does give me an indication of my overall fitness. It also allows me to compare it to the various fitness apps that use algorithms to estimate VO2Max.
As you can see my VO2Max was estimated at 45.2 in December. I was a little surprised that the recent test showed it to be 44.7. The peak Vo2 is much higher in June for a similar heart rate. Again you can see that the test machine hasn’t captured my anaerobic threshold, which may have affected the calculation as it doesn’t make complete sense.
Key takeaways from my VO2Max test
The Vo2Max test gave me confidence that the low intensity, zone 2 training is delivering the expected outcomes. In terms of improving my fat burning and power output at low intensity. I feel pretty confident I go can farther and faster for the same amount of effort compared to 6 months ago.
There is an anomaly in my Vo2Max coming out very similar which doesn’t make complete sense, but that is less important than the other findings.
My DEXA Scan
A DEXA scan is considered the gold standard for measuring things like body fat, bone density, visceral fat and lean muscle mass. I found this really insightful and helpful in understanding my body composition.
The latest test found that my body fat is 23.4%, a very small reduction from the previous 24% My visceral fat (the fat around your organs) doesn’t look to have changed. On a positive note my lean muscle mass has increased as has my bone density.
June Dexa scan
My bone density came up low, this wasnt a huge surprise to me given my age and that I’d spent most of the last year cycling as my main exercise as Id had a running injury. I also haven’t done weights for a number of years.
June Bone density scan
You can see from the graph above that my bone density is towards the bottom of the range but has increased during the last 6 months, most likely due to me doing more strength training.
The tables below show the details on the body fat decrease and bone mass increase in addition to showing that my lean muscle mass has increased by just under 1 Kg, not a huge increase but again is something I’m attributing to me doing strength training.
Key takeaways from my DEXA Scan
The recent DEXA Scan helped me understand that I STILL need to lose fat, in particular visceral fat. So I need to put mmore effort into eating and sleeping better.
How I’m using the insights from the latest tests
The tests have again given me great insights into both my fitness and health.
Learning from these tests mean that I’ll be:
- Continue doing 80% of my exercise as Zone 2 sessions, maintaining my HR at around 125 to 130 bpm. This is slightly higher that the previous 115 to 125 Id focused on.
- I’ll also try and make sure I do an indoor zone 2 session per week, so that I can continue to push my power output at this effort level.
- I will aim to maintain the high intensity sessions each week as this will help improve my Vo2Max
- Get back to doing weight training at least once per week. This has really helped with bone density and lean mass
- Taking it more seriously to stop snacking between meals and increase my protein consumption per kg of body weight alongside a reduction in carbs
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