Walking and cycling to work can be healthy and can save money. Exercise is even known to improve productivity. Since tiredness affects job performance especially if it's a physical job, it's very important to save our energy. We'll need it for 8 hours.
How can we walk or cycle to work without becoming tired?
The commute can range between 30 and 60 minutes. What's the highest heart rate that we can use and not get tired? If we use zone 1 on the way to work, is it safe for our performance? They say it's so easy that you felt like you didn't ride your bike. If we use the 180 minus age heart rate on the way home, would we be fully recovered by the next morning for work?
If more time is needed for recovery, an alternative might be to exercise heavily only after work on Fridays, and Saturdays.
I'm asking this question because my job is manual labour and friends are concerned that when I bike to work, I get too tired. It requires core strength.