Early last July I bought a Polar FT7 heart monitor. I’d never used one of these before but apparently they have revolutionised training since my racing days. I decided to buy one because, being very unfit and over weight, I thought it might help me not over do things and do any damage. But I only unpacked it and started to experiment with it last week. I have discovered that the monitor calculates and records maximum and minimum heart rate (HR) for each training session, the calories burnt, session length and how many minutes in the fitness (cardio) range and in the fat burning range. Since losing weight is my priority at the moment I have decided to try and do most of my training in the fat burning range. Obviously I want to get stronger and fitter and exercising to lose weight will still contribute to this but concentrating on losing weight would be of more immediate benefit. Even at my current fitness level and strength I would get up the hills I’m struggling on a lot easier and faster if I had a stone or two less to lug up them. All the formulae for calculating the various exercise zones require a maximum heart rate figure. Some also require a resting heart rate figure as well. Using my HRM my pulse at rest is about 50 and in one strenuous effort on the turbo I saw a 167 maximum. However most of the formulae for maximum heart rate give a figure between 155 and 164 for my age so 160 looks like about right. Using the formulae from Heart rate monitor training for cyclists (a very entertaining article as well as informative) my training zones are as follows:
- Zone 1 (60-65% of maximum heart rate): For long, easy rides, to improve the combustion and storage of fats. (102-110)
- Zone 2 (65-75% of MHR): The basic base training zone. Longish rides of medium stress. (110-128)
- Zone 3 (75-82% of MHR): For development of aerobic capacity and endurance with moderate volume at very controlled intensity. (128-140)
- Zone 4 (82-89% of MHR): For simulating pace when tapering for a race. (140-151)
- Zone 5 (89-94% of MHR): For raising anaerobic threshold. Good sessions for 10- and 25-mile time-trials. (151-160)
- Zone 6 (94-100% of MHR): For high-intensity interval training to increase maximum power and speed (160-170)
A good article from Bikeradar.com suggests a variety of turbo sessions for different objectives including one on fat burning: Turbo trainer workouts for all seasons
Tuesday 30th October: turbo 20 mins using HRM [242 calories, fitness 19.26, fat burn 4.58, max 162, av. 120] But the first 5 minutes where with the HR monitor running before I got on the bike so, in the light of the next 2 results, I suspect the 4.58 fat burn minutes were before I got on the turbo!
Wednesday 31st October: 25 min turbo [tried to stay in fat burning HR zone 102-110 with a burst at the end after 20 mins, but: 210 calories, fitness 21.50, fat burn 3.06, max 154, av. 112 which compares unfavourably with yesterday].
Thursday 1st November: 25 mins turbo [first 20 mins 110-128, 100 revs sprint at end and recovery, 270 cals, fitness 24.25, fat burn 0.34, max HR 164, av HR 127, clearly my fat burn HR range is well under 100!] According to this chart my fat burning bps range is 93 to 109
Update: Friday 2nd November. Today I wore the HRM to work and kept it running for about 4 hours. My HR varied between 58 and 108 (with 123 going up stairs) and it seems I spent at least half the time in my fat burning zone. If this is so it looks like I don’t need to train on the turbo for fat burning as my current state of fitness means I just need move about a bit!