How Many Miles a Day Should I Run?

How many miles a day should I run to maintain base running fitness?

As a running coach, I get that question all the time. An athlete carves out 2-3 months for race training but after the race, training needs to return to a more reasonable routine, one that fits into life, work, and the dozens of other commitments you have. But, you don’t want to lose all of that fitness you worked so hard for, so you wonder what is the minimum you must run to maintain your fitness?

I use a couple of innovative rules to reduce running to its minimum yet maintain your base fitness and fit the sport into your life. Plus, with this minimal training schedule, you can easily jump back into more formal training at any time.

The 3 & 3 Rule for How Many Miles a Day You Should Run

To maintain your cardiovascular and neuromuscular fitness, you need to run at least three days out of every 7-10 days. Any less and your fitness declines, and you stop feeling like a runner. This strategy works great for runners who need a break from serious training and provides a lot of flexibility so running easily fits into your life.

Additionally, you should not go more than three days without a run. That’s the 3 & 3 rule: 3 runs every 7-10 days with no more than 3 days between runs. If you follow this rule, you’ll hold onto your base fitness until you ramp up training again.

The 30/60/90 Rule to Maintain Running Fitness

The other rule to use in your minimal training period is the 30/60/90 rule. For the majority of your runs, you run for 30 minutes. Thirty minutes is the perfect amount because it isn’t a big time commitment, but holds onto your base fitness.

While most runs are 30 minutes, once every two to three weeks, you do a 60-minute run. A 60-minute run every few weeks is a must if you want to be ready to jump into a race plan in the future. Plus, running easily for an hour every now and then keeps you connected to the satisfaction of a longer run.

The third part of the 30/60/90 rule is that every three to four weeks, you should do a 90-minute run. This longer run every three to four weeks does wonders to maintain your base fitness, leg durability, and mental toughness. These occasional 90-minute runs are good for all runners, but especially for runners who may want to run a half marathon or marathon in the future. Plus, you stay connected with running friends who are still on the usual weekly long run schedule.

Does This Really Work?

Yes, and the reason is that it addresses all four aspects of running fitness – cardiovascular and neuromuscular fitness, as well as fatigue resistance and mental toughness.

Your running fitness necessarily fluctuates from your base fitness to race fitness, so let’s take a closer look at both.

Base Fitness vs. Race Fitness

Base fitness is your stable yet slowly improving fitness level that comes from being consistent in your running routine. Race fitness sits on top of your base fitness and maximizes all aspects of running fitness. “Fitness” in running is a mixture of cardiovascular and neuromuscular fitness, as well as fatigue resistance and mental toughness.

Cardiovascular fitness is often measured by your VO2 max. VO2 max is the amount of oxygen you can use. A higher VO2 max indicates improved cardiovascular fitness. But, there are two aspects of VO2 max to consider when looking at maintaining your cardiovascular fitness between races.

First, your VO2 max gradually increases with 2-4 years of running. Then, VO2 max stabilizes before beginning to decline with age. This VO2 max, the one you have after being a runner for a few years, is what I think of as your baseline VO2 max.

The other VO2 max measurement is when you are at your peak for a race. You get a jump in VO2 max when you add intense training like hill workouts and speed work. Naturally, when you stop race training, your VO2 max will return to your baseline.

For example, I recently had a runner finish a half marathon. Before the race, their VO2 max was estimated at 56 on their smartwatch. Their half marathon recovery plan included 4-6 very short and easy runs over two weeks, with mostly rest for recovery. After the two weeks of this low-volume, low-intensity running, the watch said the VO2 max was 53—the athlete’s baseline.

But VO2 max is not the only aspect of fitness you want to maintain between race plans. You also want to maintain your “feel” of being a runner. You know this feeling because if you ever take a week or two completely off of running, the first few runs feel like you’ve never run before!

Luckily, your neuromuscular system is really quick to respond, so you don’t need that much running to still feel like a runner when you lace up your shoes. That’s a key reason the 3 & 3 Rule works. By never going more than three days without a run, your neuromuscular system never goes dormant. While your running economy at faster paces may slip from your peak race fitness, you still feel smooth and coordinated on easy runs, and it’s easy to regain your economy at faster paces when you return to race training.

Lastly, your fatigue resistance and mental toughness should be addressed during periods of minimal training. If not, your return to formal training is harder than it needs to be.

This is what is often missed in minimal training plans. Runners focus only on cardiovascular fitness, but you know, as a runner, that a big part of race training is boosting your mental toughness and resistance to fatigue.

That’s exactly why the 30/60/90 rule is so important. You could just run 30 minutes each run and probably maintain your base cardiovascular fitness. But you’ll find it harder to return to formal training. Just adding those occasional 60- and 90-minute runs works wonders for maintaining a base level of fatigue resistance and mental toughness.