Body Composition Profiling #2

I went back to Birmingham University High Performance Centre for my second body composition profile this week. Once again I had the 7 skin fold measurements and 4 muscle girth measurements taken. This session was really concerned with seeing how I had done with achieving the goals set in the first session. They were:

  • maintain muscle mass at 46.7kg;
  • decrease total skin folds by ~5mm over the next month (around a 2 lb loss)
  • decrease abdominal skin fold the most.

Comparative Data

BODY FAT (Skin folds)

Sites mm (30/05/2013)  mm (05/07/2013)
Triceps 6.7  5.9
 Subscapular 10.8  8.7
 Bicep 4.2  3.7
 Supraspinale 9.8  7.8
 Abdominal 23.1  12.1
 Front Thigh 7  6.5
 Medial Calf 5.1  4.8
 Sum of 7 66.5  49.4



MUSCLE (girths)

Sites mm (30/05/2013) mm (05/07/2013)
Upper arm 31.4 30.7
Forearm g. 28.8 28.9
Mid thigh g. 56.8 56.4
Max calf g. 39.5 38.8
Height (cm)  174.8 174.8
Weight (kg)  74.9 72.1
Muscle Mass (kg)  46.7 46.1
%  62.3 63.9


Goal 1 – Maintain muscle mass at 46.7kg;

My overall muscle mass has slightly decreased from 46.7kg to 46.1kg. Clearly if you want to take the goal strictly on face value you would suggest that this goal wasn’t achieved. However this is a very small loss; 0.6kg that when taken in context with the reduction of skin fold measurement means that my overall muscle mass % has actually increased from 62.3% to 63.9%. It’s important to remember that in mountain biking power to weight ratio is what is important not absolute power output.

Goal 2 – Decrease total skin folds by ~5mm over the next month (around a 2 lb loss)

It’s fairly easy to see from the first table and the graph that all of my skin fold measurements have decreased. My overall SUM of 7 has gone from 66.5mm to 49.4mm a decrease of a whopping 17.1mm! This equates to roughly 4.8lbs (2.2kg) of body fat. Clearly I smashed this goal so I’m very happy.

Goal 3 – Decrease abdominal skin fold the most.

I thought it the best way to compare skin fold site measurement reduction was to create the table below of % lost.

SKIN FOLD % REDUCTION BETWEEN 30/05/2013 and 05/07/2013

Sites  % Loss
Triceps  11.9
 Subscapular  19.4
 Bicep  11.9
 Supraspinale  20.4
 Abdominal  47.6
 Front Thigh  7.1
 Medial Calf  5.8
 Average Loss  17.2

If it wasn’t already clear from the absolute measurements the table above shows very clearly that the largest reduction was very obviously at the Abdominal site (47.6%). Goal completed big time! I thought it also interesting that the next 2 largest reductions were at the Subscapular (19.4%) and Supraspinale (20.4%) sites which are also sites on the core of the body. I’m not really sure what average loss tells us or if it’s really that useful but I calculated it anyway at 17.2%.


1. Maintaining muscle mass at 46.1kg. I’m going to be doing a bit more gym work in the next month I would hope this might actually increase. If the weather stays like it is at the moment though it’s going to be hard to cut down the miles.

2. Decrease total skin folds by 5mm.


I will be upping my baseline calories to 2040 kcal. I’m aiming to do a lot more gym work over the next 8 weeks and so my body will need more energy if I’m hoping to build any more muscle. Last time I had a goal of eating at least 150g of protein per day. I did this almost every day and it clearly worked for me as my muscle loss was so minimal. I’m going to be keeping to this same target moving forwards.

I started to concentrate on when I was eating to be more focused on getting in the fuel before rides. I think this worked well as I have been feeling stronger and more energised on my rides over the last few weeks. I have also not had any issues with mild bonking the day after a ride and have been in a better mood generally so I think that the food side of things is coming together now.

I have booked in for another profile in 8 weeks time, so I just need to keep watching what I eat and keep riding the bike.


So, what do you think ?

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