1. HITT
In recent years HIIT (High-intensity interval training) has become the go-to class when it comes to getting in shape and even Castano is a fan.
"Short bursts of intense exercises with short breaks – it's not only good for burning calories, it’s also great to increase stamina – using aerobic and anaerobic systems to help you boost your fitness fast. I’m a fan of HITT as it’s short, efficient and effective," he tells Men's Health.
2. PUMPING WEIGHTS
Shifting tin is best for building muscle, there's no denying that. But Castano says you can alter the workout to also improve your aerobic capacity.
"The trick is to shorten those rest periods to less than 30 seconds and focus on back to back exercises that work the same muscle group AKA tri sets and supersets," explains Castano.
"If you don’t need the rest then don’t take it. You should be leaving that session sweaty and definitely out of breath - look for over 130 BPM."
If you're struggling to lift weights continuously, incorporate bodyweight exercises like push-ups.
3. STAIRS
If you've ever taken the stairwell, you'll notice how much you're huffin' and puffin' once you get to the top. Now, try running up and down for prolonged periods. This is the perfect exercise to boost your fitness level, says Castano.
"To break it down, the higher the heart rate the more oxygen we need to take in, leaving us breathless," he says.
"If we do a few sets up and down while pushing past your limit, we will see quick results. The more you do it the better you’ll get."
4. CYCLE
Coming back from injury, getting back into exercise can be tough, especially if you're worried about aggravating any damage you've done. Castano recommends jumping on a bike to take some of the stress off your body.
"There are so many cycle classes out there now and the best part about it is that is non impact so it’s gentle on the joints and muscles. Don’t underestimate how effective a bike can be. Riding for long periods of times and working intervals Is a perfect way to boost those fitness levels."
5. SPRINTS
If jogging is a little too slow for you, give sprinting a go. The best bit? Your heart rate is elevated even in between high-intensity bursts.
"It can be done outdoors or on a treadmill – my go-to is 20 seconds on and 10 seconds off done at your max and repeat that 5 times. The benefits of sprinting is that it’s a complete workout. Using short bursts and short recovery times is going to elevate the heart rate helping boost those fitness levels," Castano adds.