When the sun is shining and the sky is blue, the last thing we want to do is workout inside a stuffy gym.
Luckily there are plenty of places in London where you can up your fitness outside.
From lidos to running clubs, check out our roundup of the best places to get your heart pumping in the great outdoors.
Nike Running Club and Nike Training Club
Pick up the pace with Nike's 'Speed Run', up your stamina with their 'Long Run', explore the city with 'Local Run' or feel the burn with 'HIIT and Run'.
If running isn't your thing, lunge, jump and squat your way to a toned body with the Nike+ Training Club.
Classes can be found across London including at NikeTown, Covent Garden, White City, Stratford, Blue Water and Mile End.
Visit nike.com for details.
British Military Fitness
BMF offer hour-long military-style fitness sessions to workout your whole body from £27 per month (equivalent to £5.40 per class).
Each session includes a warm up, cardio and strength training, a cool down and stretches. Expect push ups, squats, star jumps and burpees.
Classes are held across London parks including Finsbury Park, Richmond Park, Wandsworth Common and Shoreditch Park.
You can try your first session for free. Visit britmilfit.com for details.
Project Awesome offer free running and games sessions to "motivate and encourage people of all ages, shapes, sizes and fitness levels to get outside, sweating and smiling". Expect lots of high fives.
Sessions are currently held at City Hall and Primrose Hill.
Visit projectawesomelondon.com to find the next meet-up.
Get fit by helping with community projects such as painting or clearing rubbish or jog to see an isolated person.
GoodGym is available at various London locations, all you have to do is sign up to connect with people in your area - it won't cost you a penny.
Find out more at goodgym.org.
London Fields Lido
London Fields Lido is the only 50m Olympic size, heated outdoor swimming pool in London, so it's perfect for anyone not quite brave enough for cold water.
The pool, which is located in Hackney, offers lane swimming all day from 6.30am-9pm, plus swimming lessons for children and adults.
Swimming starts from £4.80 for non-members and £3.45 for members.
Visit better.org.uk for more details.
Embrace your inner child with the playground-inspired games at Rabble. Exercises include ultimate frisbee, British Bulldog, dodgeball and lots of laughing.
Prices are £10 per class (or less if you buy a package) and sessions are available across many UK cities.
Check out joinrabble.com to find your nearest session.
Park Run offer free, weekly 5K runs open to all abilities, from first-time runners to Olympic athletes.
Sessions take place around the world (including various London locations).
Visit parkrun.org.uk to find the next race near you.
Get out of the boxing ring and don your gloves outside with Boxit Bootcamp.
Classes include a warm up, pad work, weights, cardio and ab exercises, plus things like press ups, squats, lunges, sit ups, sprints and team fun.
All classes, held on Clapham Common and Wandsworth Common, are open to men and women for £10 per single session (or less for packages).
Find out more at boxitbootcamp.com.
Hampstead Heath Ponds
Splash your way to a healthier body at Hampstead Health by hitting up either the Ladies’ Pond, Men’s Pond or Mixed Pond.
The Ladies’ and Men’s Ponds are the only life-guarded open-water swimming facilities open to the public every day of the year in the UK.
For more information about swimming at Hampstead Heath, visit cityoflondon.gov.uk/things-to-do.