Bikers race AmaLea on the Danube River.

(10:10 a.m. EDT) -- Thinking about taking a river cruise, but fear that all that schnitzel and strudel will throw your diet off track? Indulging in the local delicacies is part of the fun of exploring Europe, yet no one wants to come home with an extra five pounds.

Luckily, river cruises have been getting more active with their excursions, offering biking, hiking and in some cases, canoeing and kayaking, as port options. AmaWaterways is the river cruise line that pioneered the trend, being the first to carry a complimentary fleet of bikes onboard. They've been expanding the options every year, to the point where nearly every port stop has something that will get your heart pumping. Next year, they will expand fitness opportunities onboard, putting a dedicated wellness coach on every ship.

We're with AmaWaterways on the Danube this week, onboard the line's brand-new ship, AmaLea (stay tuned tomorrow for christening coverage). We've been diligent about our tours, choosing mostly active ones (although our willpower broke down in Bratislava, where we took a beer tour instead of the bike tour or castle hike). Here's a look at what the ship is like and what the line has coming.

Perched high on a hill above the Danube, Buda Castle is the final destination for hikers on the active Budapest tour.

Hiking in Budapest

The Hungarian capital of Budapest, where most Danube River cruises begin or end, is divided into two parts. The more modern city of Pest is flat, and the historic castle district Buda sits high upon a hill overlooking the river. There's a funicular (cable railway) that most people take to get to the top, but Ama's active tour promises that you'll be able to climb the stairs instead.

We did, all that, and a whole lot more. Our guide proceeded at breakneck speed throughout both sides of the city, barely pausing to answer questions. The tour hit all of the highlights that you'd see by bus, including St. Stephen's Basilica, the Hungarian Parliament, the shoes on the Danube -- and that was before we crossed the Chain Bridge and trudged up toward Fisherman's Bastion.

Some of the other people in the group clearly had not expected the active tour to be quite so active -- and they welcomed the option to take the bus back to the ship. We wanted to indulge in a piece of cake from Gerbeaud, Budapest's most famous cafe, so we sucked it up and walked the 45 minutes back to the ship.

At the end of the day, we saw all of the sights and completed 18,000 steps on our FitBit -- and garnered a few blisters on our toes. We also crashed for an epic nap. No guilt about that cake, though; we earned it.

After a 16-mile bike ride from the ship in Vienna, AmaLea passengers explore Klosterneuburg Monastery.

Biking in Vienna

The slate of ship tours available on AmaLea encompassed the traditional -- a city tour -- and active -- two bike tours. We chose the morning option, a 16-mile bike ride to Klosterneuburg Monastery outside the city.

While some river cruise lines carry e-bikes onboard that make pedaling easier, AmaWaterways has regular bikes, the ones that require your own power (no cheating here!). We found them easy to adjust -- guides will help you -- and use; helmets are provided. There are no baskets, but there are straps to secure your bag on the back.

The ride out to the Monastery was flat and straightforward, with only a few instances where you'll encounter cars. Once we arrived, we locked our bikes and were able to meander around the church and grounds, even have a cappuccino with the members of our group.

Our fellow passengers included group of five avid cyclists from Pittsburgh, who had originally intended to book a bike-to-barge tour before finding AmaWaterways. "That trip wouldn't nearly have been as comfortable as this," one of them told me. They would be perfect candidates for the Backroads bike cruises that are run in partnership with AmaWaterways; these sailings -- offered on the Rhine, Danube, Seine, Douro and Mekong-- rack up serious mileage, with stretches that go up to 43 miles.

We had good intentions of taking the 13-mile afternoon bike tour too, but again, the combination of jet lag, constant activity and some wine at lunch led us instead to a solid two-hour nap. We're clearly not Backroads material -- yet?

Luckily for inexperienced riders, most of the path along the Danube River is flat.

Biking in the Wachau Valley

We awoke in Austria's gorgeous Wachau Valley, a UNESCO World Heritage Site for its famous vineyards, with sore hamstrings and an unpleasant awareness of our glutes. No matter. We were confident we could power through the day's bike ride, a 21-mile from the small town of Weissenkirchen to Melk Abbey (we had already done the other active choice, a hike up to Durnstein castle, on a previous river cruise).

Warnings that the route, with several hills, would be the hardest on the itinerary did not dissuade AmaLea's hardy passengers; more than 20 people signed up for the ride. And indeed, the trip was not nearly as hard as we expected. Austria's spring has been unusually warm, and roses bedecked the adorable small towns, many of which still had their May poles up. Every corner presented a photo op, and our sanguine leader, who had once served as an AmaWaterways cruise director, allowed us to stop along the way for Instagram moments. Perfection.

Approaching thunderstorms made the final uphill push toward Melk Abbey a little more fraught (and rough on the quads). Still, we arrived before the rain and even had time to walk around before meeting up with tour buses to take us back to the ship. Some of us rewarded ourselves with a signature piece of apricot cake. Bike, cake, nap -- are you sensing a trend?

Apricot strudel is a delicious reward after a 21-mile bike trip.

Spa-ing in Linz

After two solid days of rides, we're taking the day off in Linz. We waved good-bye to our cycling friends -- we're now a pack, of sorts -- who were spending the morning taking a seven-mile bike ride through the city and stayed on the ship.

AmaWaterways has a massage room on most of its ships, and prices are less than you'll find on ocean vessels. We shelled out 60 euro for a 60-minute massage, and it was well worth the indulgence.

There's still cake to consume, however, so our fitness diligence will continue. In Passau tomorrow, we're signed up for a 14-mile bike tour that will take us by scenic towns along the Inn River. There's also an option to hike up to a castle. We'll be in Germany instead of Austria, however, so we suspect our reward for the ride will be beer instead of dessert. Or both? You only live once.

Coming Next Year: Wellness Coaches

Judging by the enthusiasm on our ship, AmaWaterways' investment in bike tours and active cruising is a big hit. It's certainly a trend that's been noted by competitors; Avalon Waterways has been offering Active Discovery itineraries for the past few years and will have active excursions in most ports in 2019. Scenic Cruises, Emerald Waterways, Vantage, Uniworld, Tauck and Crystal all have bike excursions (some with e-bikes that make this kind of tour more accessible). Even Viking River Cruises, long a holdout when it comes to bikes, is adding active excursions in 2018 and 2019, although their trips come with an extra fee.

AmaWaterways trialed a wellness coach on its ship AmaLyra in 2017, and rolled out the program to five more vessels this year. Next year, it will appear on all ships, said AmaWaterways co-owner Kristin Karst, who has been on our sailing.

With the wellness coaches, passengers will be able to take morning classes in stretching, yoga and core; afternoon classes are also available, although these have been less popular with passengers, Karst said. While most of these activities currently take place on the top deck (and in the lounge during rainy weather), the line's upcoming double-sized ship AmaMagna will have a full-size fitness room among its offerings, as well as a more robust spa and salon, Karst said.

We're still onboard so we have yet to know if the active excursions staved off extra poundage. We definitely feel healthier than we normally do on a cruise, a whole lot more sanctimonious, and a touch more ambitious. Could this spring jump into fitness keep going once we get back home? One can hope.

--By Chris Gray Faust, Managing Editor