Hi guys,

your group helped me out a few weeks ago when I think I was under-eating. I was eating 1520 based on trying to lose 2lbs a week on MFP and I lost a lot of weight exactly to schedule. However, the rate of loss suddenly slowed and the scale didn't move for a week or two. Also, I experienced a brief spell of hunger and urge to stuff face which hadn't happen in 3 months. With the help of your group, Scooby's website and my Tanita BC 1000 Scale that measures Body Fat % - I figured out that I was losing lean significant lean body mass along with the fat. From then on, I increased calories to my Katch McCaddie BMR figure of 1850 and increased the amount of Protein in my diet - I'm now trying to target 1850 with 40pc protein, 30pc fat and 30pc complex carbs. I'm pretty sure I must have been edging towards 'starvation' mode as things have now gotten back on track with my fat loss, the loss of muscle mass has reduced and no hunger pangs. I'm quite pleased as it was a bit disheartening at the time.

From working out with my Garmin Forerunner watch, I came across a company called NewLeaf Fitness who offer metabolic assessments via personal trainers in gyms around the world. I've just completed one with MIke Mills on a work trip (flight) to Los Angeles.

The assessment starts with 20 mins sitting around just breathing into a mask where your Oxygen take up and CO2 production is analysed and recorded to give an RMR (Resting Metabolic Rate) figure - mine came out at 2007 and the advice that this is the minimum caloric intake I would need to prevent muscle loss while dieting - again pretty close to where I am at now.

There is then a 20 minute exercise assessment to identify your personal accurate Heart Rate Zones for exercise - your Aerobic Base, Anerobic Threshold, Max HR and VO2 max. The very interesting piece of information in this metabolic assessment is what % of energy the body is burning from FAT v CARBS within each HR Zone and how your metabolism can be 'trained' so that you burn a higher % of fat as your HR increases - meaning you become better at endurance sports or more athletic because you can continue to use fat as your primary fuel source even as exercise becomes more intense.

For example, currently in Zone 1 my HR is between 122 and 138 and in that range, I burn 8-10 calories per minute but 70% of those calories come from fat stores and 30% from glyocgen in the muscles (carbs).

in Zone 4 my HR is above 162 - the calorie burn is 15 calories per minute but only 5% of that is coming from stored fat, the other 95% is coming from glycogen.

There is debate among scientists about low intensity versus high intensity and I'm not qualified to comment on that.

What does make sense to me though is that being able to burn a higher % of fat at higher intensities means that I will use more of my stored fat on workouts and I will be able to workout for longer at a higher intensity - ie become more athletic.

The key point in all this is that the way to achieve this is not to do what I've been doing up to now and just doing 'moderate high' cardio but to alternate between 'recovery' cardio where I stay in zone 1-2 and other days where the zone is taken up to 4 and 5 - intense cardio. Apparently the low-end cardio 'recovery' sessions help your body to increase it's fat utilization at higher zones and the intense sessions increase your overall fitness (VO2 Max) - your bodies ability to take up the Oxygen you are inhaling.

Anyway, it's nice to have the metrics to confirm the general formulae I've been using up to now to lose nearly 15kg and I feel like I have a kind of road map and goals which is what I need to stay motivated..

If you are interested, just google New Leaf Fitness or some of the other terms I mentioned..

Cheers - best of luck to you all and thanks for this group...

Barry