You can develop your overall fitness by working on three key areas: your cardio endurance, your muscle strength and your muscle endurance. Whereas some workouts target very specific areas (to improve things such as muscle size, tone or performance), improving your general fitness is a broader goal that relies on a combination of cardio exercise and weight/resistance training.

We would suggest you include a mix of cardio exercises and weight/resistance training exercises into your weekly workout routine to make you feel fitter and stronger.

PureGym Insider Kay has shared a selection of workouts that will help improve your all-round fitness:

The following exercises will give you a good cardio workout and they can all be carried out on either a rower, treadmill or bike. Mix up your equipment choice to keep your workout fresh and interesting:

Beginners

1 round = 20 seconds sprint + 1.5 minute rest

Complete 10 rounds

Intermediate

1 round = 30 seconds sprint + 1-minute rest

Complete 10 rounds

Advanced

1 round = 30 seconds sprint + 30 seconds rest

Complete 10 rounds.

A kettlebell is a super versatile piece of gym equipment which will give your whole body a good workout. Kettlebells can be used to intensify squat, lunge, abs and arm exercises, and as such using them in your workouts will strengthen your leg, arm and core muscles:

Kettlebell workout

Completing all five exercises = 1 round. Aim for 5 -- 10 rounds:

1. 20 seconds of kettlebell swings (watch how they are done here). 10 seconds rest.
2. 20 seconds of goblet squats. 10 seconds rest.
3. 20 seconds of farmer's walks (kettlebell in each hand). 10 seconds rest.
4. 20 second of kettlebell halo. 10 seconds rest.
5. 20 seconds of windmills (watch how they are done here). 10 seconds rest.

See the workout in action here.

According to our latest research on popular gym equipment, the TRX system is one of the least used pieces of apparatus in most gyms. However, our gym managers believe it's also one of the most effective pieces, helping to improve muscle strength in your legs, arms and core. The workout below is a great way to improve your general fitness, and is a much better way to spend your time in the gym than waiting to use busier machines:

Completing all six exercises = 1 round. Aim for 5 -- 10 rounds:

1. 20 seconds TRX Overhead squat. 10 seconds rest
2. 20 seconds TRX Y fly. 10 seconds rest
3. 20 seconds TRX Rows. 10 seconds rest
4. 20 seconds TRX feet elevated press up. 10 seconds rest
5. 20 seconds TRX hamstring curls. 10 seconds rest
6. 20 seconds TRX knee tucks. 10 seconds rest

For more workout ideas, check out our free workouts guide.