The best intentions of becoming a Fat adapted (Keto) athlete can go out the window if one basic rule is ignored…. Heart Rate!
Heart rate determines how your body will allocate nutrition through the system. In low HR conditions under 70% you will encourage your body to use fat as a resource, as you creep up towards 80% and beyond the conversion rate becomes unachievable and glucose becomes the primary fuel. So how do you become fast and fuel efficient?
The secret is patience, the first 4 weeks to 2 months need to be dedicated to increasing your aerobic threshold that is exercise under 70% of max HR (220 – age, for general use) If you can’t run slow enough to keep it under 70% walk, the most important thing is adaption. The gains will come quickly if you do. Pushing your body beyond this threshold will improve your cardiovascular fitness but does little to improve your fat burning capacity. As more and more time is spent under this 70% threshold your fat conversion capacity will increase and more energy will be delivered to your system, allowing you to pick up the pace without picking up the HR, imagine how a stream becomes a river.
Once you are able to easily maintain a steady pace at 70% of max, include one HIIT HR session in the week. This would be a session where the goal is to push your heart rate up to beyond 80% for a short duration say 2 minutes and then allow it to drop for 2 mins then repeat. Start by making the activity time and the rest time equal until you can do 10 repeats. Then reduce the rest time until it is half of the activity time. A variation on this would be to do 2 mins at 80% rest then 1 min absolute max rest…repeat. This will improve your anaerobic threshold, but I must stress this threshold can only move up on an increased aerobic threshold.
Regardless of your ability and current fitness level the fastest way to improve your endurance capacity is to SLOW DOWN. Most of your sessions should focus on aerobic less than 70% Max and a max of 2 sessions per week on Anaerobic 80% plus.
It is not possible to compare heart rates with friends as a measure of reference as we are all different, some people struggle to raise their HR others can go way beyond their theoretical max which is why a % is used rather than a number to structure workouts. I good indicator of progress is how quickly your HR drops after a max effort. Your waking HR can be used as a gauge of fitness level, the lower the better. Waking HR is an excellent indicator of over training. If you measure you HR as you wake up each morning before getting up and your HR is a number of beats above the norm skip the session, you are either over trained or getting ill, and training either way will be counterproductive.
70% can be calculated like this
35 year old
220 – 35 = 185
185 x .70 = 130
130 beats per min = 70% Max HR
Keep it slow to go Fast!