How strenuous is the Heart of Portugal tour?

Susanstrup,
I was on the Heart of Portugal tour a few weeks ago and loved it!

I've previously done two other Rick Steves tours that I thought were more strenuous: Greece and Barcelona/Madrid.

While in Portugal, the only day I felt really tired from walking was on a day before the tour began when I had chosen to walk a great deal in Lisbon...but that was my choice.

From my perspective, the tour days with the most walking were:
Day 2: neighborhoods of Lisbon
Day 10: Porto food tour
Day 11: Porto walking tour

On the tour, you have the option of opting out of an activity (just tell the tour guide). Especially in Lisbon, good public transportation is available if you want to reduce the amount of walking.

I was on the Portugal tour earlier this year, and found it more challenging than expected.
I was expecting hills in Lisbon, but really nearly all the places on the tour were hilly. The added issue is the sidewalks are not concrete, but made of small stone blocks. Not flat but somehow slippery, too. Since I'm a bit of a klutz, I felt I had to watch every step. Luckily it only sprinkled a bit one day, because I imagine that would have made it worse.

I agree that due to the cobblestoned streets, everyone needs to carefully watch their steps in Lisbon. I thought of one other factor: will you have difficulty pulling your wheeled luggage? Your tour might not have the same hotels as my did, but we needed to pull luggage uphill in Obidos and Evora.

I agree with the sidewalk comments.
Use rubber sole shoes , not leather or plasticy soles, watch for uneven cobblestones, slippery sidewalks and stairs ( marble are the worst ) and obstructions ( tree roots , parked cars, etc).

When I travel I take braces with me ( back and knee braces) usually I don't need to use them and stay in the luggage but reassuring to have them just in case.

If you're buying new luggage get the ones with largest wheels - the cobblestones destroyed one of my suitcases with the little wheels.
Also pack as light as possible with luggage that is light as possible.

I’m just a bit younger than you and in good shape but… my feet and ankles killed me. It was from the stone sidewalks and having to wear the one pair of shoes that I brought for rain. It rained several days and did my feet in. My walking sandals were a blessing when I was able to wear them. It took several months for my feet to not hurt upon initial standing. It’s also very slippery when wet.
There is a lot of walking, we did not have much of any hills to walk with our luggage. Just a short walk.
I’d go again with a different rain weather shoe. It’s a wonderful tour.

Thank you so much for your feedback. I am wondering what make of walking sandals and rain shoes do you recommend?

I've found Vibram soles are pretty grippy.
A number of shoe brands use them, you just have to find shoes that work for your feet.