The Garmin Forerunner 35 has a built-in GPS and tracking modes for cycling, walking, indoor or outdoor running, and cardio. This allows runners to track their daily workouts, training, marathons and triathlons. Cyclers can use it with cadence sensors and a footpad, but the main purpose of this watch is running. The watch is also certified waterproof up to 50 meters, although it doesn't track swimming.

The Basic Features are great for new runners getting started with tracking their fitness goals, and are located on the first screen after the time. The Garmin Forerunner 35 tracks the number of steps taken out of the daily goal, the distance gone for the day, and the total length of the workout. These stats can be tracked for personal use or be used to share and compete with others.

The Advanced Features are on the second screen of the watch, after the time. The Forerunner 35 uses Garmin Elevate technology to track the user's heart rate, and the watch keeps track of the heart rate zone, current heart rate, and calories burned. It will also track sleep. Other features include a built-in GPS to track speed, distance, and location; vibration alerts for texts, activity tracking, pacing progress, milestones, prompts, and notifications; and connectivity to a smartphone for playing music, receiving push notifications, updating software, and uploading data. The Forerunner 35 is also waterproof for up to 50 meters, even though it does not track swimming.

The Forerunner 35 received different accuracy ratings for different features, although its accuracy is comparable to similar watches by other brands. Testers found that the GPS was very accurate, although it sometimes took a few minutes to connect. The indoor tracking uses an accelerometer, which is not as accurate as the GPS. The pacing is accurate. Some reviewers noted that heart rate monitor does not have great accuracy: its averages seem good, but the current heart rates can be high or low at times, especially when the watch first starts tracking it. The sleep tracker will track sleep well when it is worn overnight, but it will register as peaceful sleep when the watch is off, which isn't accurate.

The Garmin Forerunner 35 connects to satellites quickly according to some testers, although others reported that it sometimes has trouble connecting to GPS the first time. It uses Bluetooth to run Garmin Connect for sharing data with others. The watch was designed to connect with the wearer's smartphone in order to listen to music, receive notifications, and upload data to the app. The connectivity also allows the wearer to participate in competitions with friends and family. Connecting to the smartphone can also pull up weather data such as the current weather, the day's high, low, and chance of rain by the hour.

The Forerunner 35 has a free app called Garmin Connect, which is available to download on iOS and Android smartphones. It uses Bluetooth to connect to the watch and is similar to apps offered for other Garmin watches. The app allows the user to view their data such as speed, timing, pace, heart rate, elevation, maps, calories, goal progress, and sleep. Stats can be broken by day or by activity (cycling, running, steps). Some testers found that the software has compatibility issues with their phone, but most people did not seem to have this problem. The app's interface has a simple style that is easy to navigate.

This watch has very comfortable soft silicone bands. It has holes for adjusting to different wrist sizes and stretches to accommodate in-between sizes and movement. It is not too tight, which has been a problem with other watches for many reviewers. The band is both durable and flexible, so it stays comfortable for a long time. The light weight allows the watch to be worn comfortably without constantly rolling around the wrist or weighing down the wearer. The buttons on the sides are comfortable to press and easy to use.

The face is small and square and has a black bezel surrounding the not-so-sharp (compared to other, more expensive models) screen. Reviewers liked that the band was available in four different colors: blue, green, black and white, which accommodates different tastes. Most of them liked the style, but some thought it looked like it was “hit by an ugly stick” because of the shape and display.

The Forerunner 35 has a long battery life of nine days in smart mode and 13 hours with the GPS turned on. The strap is also durable as well as flexible, which allows comfortable movement without worrying about deterioration. The face and buttons are also durable, although the face can get finger smudged at times so it might need to be wiped off from time to time. There are covers and cases available for added protection, and vendors offer 2- and 3-year accident protection warranties with the purchases. The app and software also have automatic updates to fix bugs and compatibility issues.

The face has a digital display that is updated from the previous version and works well both indoors in lower lighting and outdoors in the sunlight, great for all the activity settings that a potential wearer might want to use. The lens is made of glass. The face's length is 1.4 inches, the width is 0.5 inches and the height is 1.6 inches. The screen size is 128x128 pixels, which is not a very sharp resolution compared to phones, tablets or desktops, although it seems fine because the watch itself is small, and it is clearer than previous editions. It's prone to getting fingerprint smudges even though it's not a touchscreen, so wearers should be careful to try not to touch the screen.

The soft silicone material is very comfortable according to testers, and comes in four different color options: black, white, green and blue. It has holes for adjustability and has a bit of a stretch so it fits well for any size. It is durable and similar to the band of other Garmin watches.

The Forerunner 35 is a one-size-fits-all watch. It has an adjustable, stretchy band with several holes that allow it to work well for any wrist size, large or small. Some testers with smaller wrists thought it looked a little chunky because of the relative face size, but they said it fit well and was comfortable.

Most testers found this watch very easy to use, although a few had trouble with the GPS working or could not update the software properly to sync with their smartphone. The Forerunner 35 both beeps and vibrates after each lap or milestone, which many testers loved because they couldn't miss it. It lacks a touch screen but is easy to navigate through the stats by using the four buttons on the sides. The top left button operates the back light for nighttime visibility, different tracking modes, or preserving the battery. The bottom left button works as a back button and leads to a milestones and tracking page, adjusts settings, and sets alarms. The button on the top right allows different tracking modes for cycling, walking, indoor or outdoor running, and cardio. The bottom right button scrolls through notifications, resting heart rate, active minutes, calorie burn, step counts, weather, and previous workout data. It can also control playback of smartphone music. The back of the watch monitors the wearer's heart rate using the Elevate heart rate sensor, and the watch itself has a 5ATM waterproof rating for up to 50 meters, although it does not track swimming.

The Garmin Forerunner 35 watch is powered by a lithium ion battery, and batteries are included with the purchase of the watch. The batteries have a long life. Turning off the watch when it's not being used or turning off the back light will help preserve battery life. Garmin's watches generally have long battery lives, and the Forerunner 35 battery lasts for nine days when the GPS is turned off or 13 hours if the GPS is on for tracked running.

This watch has a lot of good features for its low to mid-range retail price. Cheaper watches are available if you don't mind taking away some features, and there are more expensive watches with similar features. For example, losing the heart rate monitor will save up to $90; color display and Connect IQ add $10 to the price; and adding a lactate threshold, advanced dynamics, and strava suffer score will double the cost of the watch.

The Garmin Forerunner 35 has several accessories that include fitness sensors, adapters, cables, apps, covers, and cases. These help improve accuracy, allow the watch to connect to devices, protect the watch from accidental dropping or scratching damage. The apps allow the user to upload data, compete with friends, and track activities and milestones. The watch is also compatible with a heart rate strap in case someone needs the extra accuracy in their heart rate monitoring data. Cyclers can use a cadence sensor and a footpad with this watch.

The Garmin Forerunner 35 is a great watch for runners who are new to fitness tracking. It tracks running, walking (steps), and cycling, and can be used both indoors and outdoors. It has a built-in GPS and heart rate monitor so that users can see a map of where they went, track distances, and see their current heart rate and range. It can also track sleep and go underwater. Users can check the weather, set goals, and enter competitions with friends and family. They can also connect with their phone for music playback, push notifications, and more. It's reasonably priced for the features it has, so new runners can start with this watch and get an upgraded one down the road if they need extra features. The Forerunner 35 also works well with some accessories which can be helpful for runners with different needs, such as more accurate heart rate monitoring, and activities, such as cycling. The connectivity is decent, especially after the first use, and the accuracy is comparable to other fitness watches, especially after the first few minutes. It is also easy to use, very comfortable to wear and comes in different strap colors. Overall, the Forerunner 35 has many good features for tracking and improving upon one's fitness level.