Make the most of the sunny weather and take your fitness sessions outside, says Liz Connor.

Over the past few months, the UK has basked in what's set to be its hottest summer on record, with spectacularly long spells of uninterrupted blue skies and warm temperatures.

It's been fantastic news for your social life, but probably not so much for your waistline; the lure of the pub garden can easily mean that the gym (quite understandably) falls to the bottom of your priorities. After all, who wants to be cooped up in a hot and sweaty spinning studio when the good weather won't be here forever?

The good news is that if you're looking for a late summer fitness kick, it's really easy to stay active while also getting your fix of sunshine. From coast to countryside, there are plenty of pursuits that can tone your arms, strengthen your abs and clear your mental clutter.

Here are just a few family-friendly, al fresco activities to try...

1. Surfing

Surfing is one of the most physically challenging watersports out there, engaging your core and stabiliser muscles as you work to bend and balance on the board. "It's great for your heart," says Harris Rothschild, senior instructor at St Ives Surf School (stivessurfschool.co.uk). "Putting on your wet suit, running down the beach, paddling out into the surf and catching waves are all aerobic exercises that hugely benefit for your cardiovascular system." Because you're usually out on the waves for at least an hour, Harris says it tests your stamina and endurance, while sculpting your back, shoulder and leg muscles.

"Most notably for our students is that the fun of surfing and energy of the ocean combined give a tremendous sense of satisfaction and happiness," says Harris. If you're lucky enough to live on the coast, you can try it right on your doorstep, otherwise you should make a play for Cornwall, Scotland and Devon where you can catch the best swells in the UK.

2. Inline skating

There's something seriously addictive about rollerblading; whether it's feeling the wind in your hair, slaloming past pedestrian traffic or getting out in the fresh air, an hour on eight wheels is pretty much guaranteed to put a smile on your face.

It's pretty good news for your figure too - all that lower-body power does wonders for your hamstrings, quadriceps and glutes, and it's easier on your joints compared with running. It's estimated that a 10-stone person can burn about 580 calories per hour of vigorous skating, meaning you won't be missing out on the weight loss benefits while putting your gym pass on ice. Best of all, skating out in nature (even if it's just your local park) can provide some much needed time for relaxation.

3. Stand-up paddleboarding (SUP)

"SUP is a great low impact muscular endurance workout if the ocean is your thing," says Matt Harass, regional group exercise manager at Virgin Active (virginactive.co.uk). Developed when surfers in Hawaii began to use paddles to propel their surf boards, SUP is a relatively new sport that does exactly what it says on the tin: you stand on a board and push yourself forward with a single paddle.

"During a SUP session you'll be firing up most of the muscles, with the lower body and core contracting as you anchor to the board and paddle," says Harass. It's pretty good fun too: there isn't the fear of getting outrageously soaked or dismounted that comes with regular surfing, so it's perfect for people who are looking for a more serene way to enjoy the beach.

4. Trail running

When the sun's shining, why not take yourself off the treadmill and on to a nature trail? "Natural landscapes offer a mosaic of horizons to stimulate your mind," says Ceri Rees, founder of Wild Running (wildrunning.co.uk). "It's impossible to run in mud and not have at least a grin on your face!"

Rees says a good trail run through rock, scree and mud will force your body to recruit different muscles that you'll need to stabilise your core. "As with any style of running there's no getting away from the full-body and highly-respiratory nature of it," agrees Elliott Upton, a personal trainer from Up Fitness (upfitness.co.uk). Best of all? He says it's accessible to everyone, costs nothing and is one of the highest bang-for-your-buck methods of calorie burning after intense weight training.

5. Cycling

"Whether it's on your daily commute or spending your weekends cycling over mountains, this is a great way to exercise, get fit, get outdoors with your friends or family, and burn a huge amount of calories while increasing stamina," says Upton.

It's not a specialist skill, so anyone can give it a go, and it's relatively cheap - there's just a one-off payment on a bike to factor in. Upton says that cycling works the thighs and often arms hard, as well as being a great alternative for those who have joint troubles where high impact exercise can cause problems.

6. Rock climbing

There aren't many outdoor sports that will be as demanding on your body as rock climbing. "It can be a real challenge for the body as every terrain, route and weather condition will be different for each climb," says Harass. "Research has shown that climbing requires significant aerobic capacity to maintain position on a rock face and anaerobic capacity for the climb."

It's a sport that you'll will need to have a basic level of fitness and grip strength to start with, but it can pay dividends on your shoulders, legs, abs and even mental capacity. There are loads of places to give it a go - "more and more indoor rock climbing centres are popping up in cities and towns all over the world," says Upton.

"It's definitely at the more intense end of the activity scale - but try it and I'm sure you'll love it."