Last night, the Rockies slept in San Diego. For the most part, they slept well. They’ll head to Colorado after today’s game, and they won’t sleep as well when they get home. This is important, and backed by the players and science, so stick with me.

I did not sleep with them, or ask each one, but the ones I did talk to all mentioned the difference between sleeping at home and sleeping in San Diego and San Francisco. “The first night we were here, everyone was talking about how well they slept,” Rockies’ starter Tyler Chatwood told me in San Francisco. “Sometimes you feel it the first night, you have a crappy night’s sleep and feel tight,” said setup man Adam Ottavino of Colorado.

Plus, science says sleeping at high altitude is hard, and that rest and recovery generally is a difficult thing up high. In 2013 a meta-study in Turkey summed up the research:

High-altitude (HA) environments have adverse effects on the normal functioning body of people accustomed to living at low altitudes because of the change in barometric pressure which causes decrease in the amount of oxygen leading to hypobaric hypoxia. Sustained exposure to hypoxia has adverse effects on body weight, muscle structure and exercise capacity, mental functioning, and sleep quality.

“I notice I feel ten years older when I wake up in the morning here,” laughed starter Jon Gray, making that link between rest and recovery that’s so important to a professional athlete. “As long as you’re able to sleep, you’ll feel good,” agreed Chatwood. “If I throw a night game and then have to be up for a day game, I’ll notice the difference.”

There’s a cumulative effect. “More often than not,” pointed out Ottavino, “you’ll actually feel okay for the first few days and then you feel a little wore down. Especially if you threw a really stressful couple of games, really exerted yourself, you just don’t bounce back as well. Sleep is not deep here.” The position players feel it over time: “The first couple days back are hard,” admitted second baseman DJ Le Mahieu.

The second straight start of a home stand was something the starters mentioned. Starting pitchers are creatures of comfort, and when each of the part of their routine is met with less effective sleep and recovery, they feel that much worse when the second start rolls around. And it looks like there’s some evidence of an effect in the numbers.

We pulled all consecutive starts by pitchers in a single park since the last expansion in 1993 and tracked the runs per nine innings as a measure of their success. This should be mostly pitchers pitching at home in two straight starts. The sample was over 500 for most parks, and the effect, though perhaps small, may be real. Here are the ten most extreme parks by elevation in both directions, with averages.

Second Consecutive Starts in Extreme Elevation Parks High Elevation First Second Difference Colorado 5.79 6.30 0.51 Arizona 4.75 4.56 -0.19 Atlanta 3.78 3.79 0.01 Minnnesota 4.82 4.99 0.17 Kansas City 4.93 5.16 0.23 Pittsburgh 4.23 4.65 0.42 Average 4.72 4.91 0.19 Low Elevation First Second Difference Oakland 4.22 4.12 -0.10 Miami 4.31 4.06 -0.25 San Francisco 4.05 4.09 0.05 New York AL 4.26 4.45 0.19 New York NL 3.84 4.04 0.20 San Diego 3.94 4.17 0.22 Average 4.10 4.16 0.05 Runs per nine inning per start for starting pitchers throwing consecutive starts at home, grouped by team since 1993.

The effect is not huge, and you might notice that the run environment is higher for the high altitude parks. But if you express the difference between starts in each grouping as a percentage, starting pitchers were 4% worse in their second start in the altitude, and only 1% worse closest to sea level. And since Denver is almost five times higher than the second-highest park, we should note that Denver starters are 9% worse in their second starts.

There’s hope! The players themselves had some coping mechanisms. “You gotta try and make yourself sleep as long as you can,” said Chatwood. “if you do that, I think you’re fine.” Ottavino has a one-year old at home, and after pitching a high-adrenaline eighth or ninth inning around 11 pm local time, finds he can’t get to sleep until two or three in the morning. “It’s a little tricky sometimes at home,” he laughed, “but I get naps in. We have one little spot, I know they’re building a new nap room for the clubhouse, but we have a little spot where one guy can catch a nap.e I usually do.”

And then there’s what you put in your body. DJ Edwards of Push Performance in Denver works with pitchers. “We really stress hydration and active recovery,” he said. “The higher elevation training it is more difficult to gain weight or keep weight on because there is a lack of oxygen cells that aid in recovery. It is more difficult to carry oxygen to muscle cells at that high of an elevation. We recommend lots of water, high nutrient dense foods. We recommend amino acids as would anyone else. Timely carbohydrate intake pre and post workout as well.”

Hydrating was on everyone’s mind. “Hydrate, hydrate, hydrate,” said Le Mahieu. Everyone echoed some form of that mantra, but Chatwood had just heard a teammate complain about it in a unique way: “Someone was just talking about having drank six or seven bottles of water and hadn’t peed yet,” grinned the starter. “Constant hydration,” affirmed Edwards. “Almost to the point where they are over hydrated.” Including hydration at night: “On the sleep side we recommend humidifiers in the bedrooms because of our dry climate.”

But the food is important, too. “Sometimes when I’m really sore I forget to eat and I can tell the difference then,” said Chatwood. “You have to crush food.” Gray said he took as many amino acids as he could, and Le Mahieu mentioned eating well. They all praised the new nutritionist and cook in the clubhouse as a real help. “Our team is eating a lot healthier because we have new guidelines and a new chef because of the CBA,” pointed out Ottavino. “Little things like that help.”

The pitchers and trainers have also adjusted their schedules. “Since I came back from surgery, I’ve thrown a lot less, and I think that’s helped,” said Tommy John survivor Chatwood. Ottavino, who had his surgery more recently, agreed: “At this point in my career, if I can skip throwing, I usually do, save my bullets and all that.”

Edwards at Push Performance has some guidelines. “Between starts we like to lift our heaviest lift the day after a start,” said Edwards of training pitchers in Denver. “That gives the most time to get them recovered. The rest of the week we really focus on movement, recovery, regaining anything lost i.e. Internal rotation, hip mobility, shoulder stability etc.”

They also have some breathing exercises for their athletes at Push. “We do focus on a lot of post workout breathing,” Edwards said. “We really want the athlete to expand the diaphragm and learn to regain their breaths quickly. This helps allow a slower heart rate and go from sympathetic to parasympathetic safely, quickly and efficiently.”

And there’s even a little benefit to this annoyance that is sleeping and recovering at high altitude: it makes you better on the road. “There is a reason why the United States Olympic Training Center is located in Colorado Springs,” pointed out Edwards. “Aerobic captivity is built because of the higher elevations. The lungs are stronger, Vo2 max is higher. The pitchers should be able to go deeper into a start at sea level.” This isn’t definitive or anything, but the Rockies are the only team in baseball since 1993 that has gotten more innings per game started on the road than at home.

Innings Per Game Started, Home & Away Top Five Away IP/GS Home IP/GS Diff Rockies 5.71 5.62 0.10 Rangers 5.75 5.77 -0.02 White Sox 6.06 6.15 -0.10 Diamondbacks 5.97 6.08 -0.11 Red Sox 5.85 5.98 -0.13 Bottom Five Away IP/GS Home IP/GS Diff Mets 5.85 6.22 -0.37 Dodgers 5.84 6.21 -0.37 Giants 5.82 6.20 -0.38 Athletics 5.73 6.11 -0.38 Padres 5.64 6.07 -0.42 Since 1993, all games started home and away grouped by team

So the next time Tyler Chatwood calls for a new ball, sighs, and rubs the seams as he looks at the scoreboard during the second start of a homestand, maybe that little asterisk will help him out a little. ‘Where are we headed next again?’