When seasons change, you routines probably change too. That's not always a good thing for your health. 

With the advent of cold weather, shorter daylight, and the school year, it's all too easy to drop the workout routines that were a fun, productive part of summer. Brett Bartholomew, a performance specialist at Phoenix-based EXOS, formerly known as Athletes' Performance, knows all about maintaining fitness as seasons change. As the trainer of countless pro football players, including Patrick Chung (above) of the New England Patriots and Colin Kaepernick of the San Francisco 49ers, Bartholomew is an expert on staying fit year-round, even as your external circumstances make it easy to make excuses. 

Understanding that this is often the time of year when great summer routines begin to die, EXOS recently published a list of 10 ways to stick to your workout. Here's the list, with comments from Bartholomew about how to make sure you're not derailed by winter and everything that comes with it. 

1. Find a compelling reason to train. 

For NFL players, this is easy: It's their livelihood. But what's your compelling reason? Visualization can help. Perhaps you envision yourself playing in the yard with your kids, running nimbly, keeping your breath, not worrying about whether you can keep up. 

The essence of visualization, says Bartholomew, is getting down to the root cause of your motivation. When he asks clients why they want to train, the first thing they might mention is losing weight. If he digs deeper, he'll learn it's so they can be more confident. Deeper still, he'll learn they want that confidence for playing rigorously with their kids. "You've got to ask the question within the question," he says. "That's usually the big key to getting people to understand their higher-level reason to train." 

2. Set precise and vivid goals.

Increments are the key. You don't have to think big at first. Maybe your first goal is simply getting to the gym three times a week in November, despite the cold and darkness. Once you know you can make it to the gym, you can shift your goals to your specific workouts: Sets and reps of the weight you lift, time spent on one machine or another. 

3. Mark time off on your calendar. 

Just the act of walling off your workout time as something on your schedule can be a huge factor in maintaining your routine throughout the winter.  

4. Make your goals public. 

Use social sharing as a form of group motivation. Let your friends know what you're doing for a workout or a healthy meal; let them know how it goes; and let them know when it's over. The support you'll receive along the way will keep you going. 

Bartholomew says this social-sharing approach has changed for the better in recent years, with the advent of fitness wearables. There was a time when fitness posts seemed like bragging. Now, he believes, the atmosphere is more supportive, because the general population can relate to the importance of routine activity. "Fitness is now less of a fervor and fad than it used to be," he says. "People are better at understanding the connection to overall health." 

5. Train with a buddy. 

In the same way it's hard to cancel on a good friend when you've made plans for a meal or the movies, it's hard to bail on a workout plan if you're doing it with a pal you don't want to disappoint. Identify another person who can help hold you accountable to your goals. 

6. Share with your significant other. 

"Couples who are active together stand a 94 percent chance of sticking with their exercise program," notes EXOS. "By contrast, 43 percent of couples who go it alone end up failing."

Another benefit to training with your spouse is that it takes away a ready excuse for not training. Bartholomew says that pinning a lack of commitment to exercise on a significant other is one of the most common excuses he hears--up there with blaming a work schedule. 

7. Build momentum.

There's a reason many trainers prefer the term "movement" to exercise. Movement connotes an active lifestyle. Exercise connotes a brief, daily interlude where you're not sedentary. The idea is to move more all day, even in small ways (taking the stairs, using a standing desk). That way, when it's time for your workout, you'll feel like you've built some momentum toward it. 

8. Rest, recover, repeat. 

How do you know when you need to rest, versus when you're just feeling lazy? Bartholomew, who grew up in Omaha and knows all about cold-weather excuses, says you should simply go through your warmup--then see how you feel. If you make it to your warmup, you've already dressed and made time for the workout--in other words, you've already bypassed some common excuses. If, after the warmup, you still feel as if you can't go, that's fine: You'll at least have been active for a little while. You'll be sitting out because of your physical condition, not your mood. 

The other key to recovery? Eat well, simple as it sounds. And if you need a boost that goes beyond actual food, be careful. As University of Florida quarterback Will Grier just found out, over-the-counter availability is no guarantee that a supplement is free of performance-enhancing substances. Bartholomew is, of course, a fan of EXOS's NSF-certified aminos, whey protein, and multivitamins. 

9. Mix it up. 

You'll keep your mind and nervous system stimulated if you are creative with your routines. Doing the same thing everyday will bore you--and the next thing you know, you'll start skipping sessions. This is another perk to working out with a spouse and/or buddy. You can try their favorite activities on for size, and they can do the same with yours.  

10. Keep expectations reasonable. 

Long-term change takes a while. Take it one day at a time. If you keep up the proper daily activity, EXOS notes, "you'll be amazed at where you end up in three, six and 12 months down the road."