Why Train Twice A Day?

It is pretty commonplace in most training circles to train twice a day. In the context of sprint training, go to any college or elite club environment and you’re likely to find the athletes sprinting in their first session of the day, followed by lifting in the second session. In football, the dreaded hell-week is composed of multiple, full-length practices in a single day. In boxing, someone may spar at one point in the day, and smash conditioning in another session.

Despite no long term research being done to investigate whether or not training twice a day is the best option for speed & power athletes, we as coaches and athletes tend to think it is most effective. This belief relies on a number of assumptions:

  • Assumption #1 – The body’s response to “CNS stress” is relatively similar no matter the specific input,, so it should all go in the same day.
  • Assumption #2 – Everybody needs to do X number of things in a given day of training to improve.
  • Assumption #3 – The pro’s do it, so I should too.

These assumptions are pervasive. Are they wrong? I can’t say that, as I am not some all-knowing mastermind. But what I can say is that I have seen enough cases of athletes benefiting more from 1 session per day than from 2 sessions, that I think coaches need to think more critically as to why they do what they do.

Assumption #1 – All intense stress inputs are equal in the eyes of the body’s adaptation.

The multi-session training day is rooted in the idea that all types of high intensity training will result in similar stress on the body, and because of this we need to keep all intense stimuli within the same day of training. Because we’d fry like an egg if we did everything in one session, we’d have to split things up into two sessions in order to “fit it all in.” Going one step further, it is commonplace to believe that any intense stress needs 48 hours of recovery before you can come back and hit it again with another high intensity stressor. Therefore, a lot of coaches avoid doing back to back single-stressor sessions (such as lift one day and sprint another day), and instead combine the high intensity work into the same day. If done in two separate sessions, these athletes are going to be training twice a day, and at the very least having overall high volumes of a variety high intensity work units.

I question this thought process. Does the body adapt to 30 meter flying sprints done at 99% intensity in the same way that it adapts to a 99% deadlift? I would venture to say that no, it does not. Now, if the adaptation is different between two types of equally intense stimuli (from a rate of perceived exertion standpoint, a.k.a RPE), then how can we go forward and assume that utilizing a variety of intense stimuli in a given day is going to do more good than it does harm?

Say you sprint in session 1, and follow up the session with some lifts in the gym. There is no way to know which stimuli the body is going to adapt to most. You can assume, and you can hope, but you cannot know. For all we know, the body could adapt to the most recent stressor, which in this case would be the lifts. Beyond the fact that we cannot predict what the body will choose respond to, 9 out of 10 people will perform worse in the lifting session if it directly follows a sprint session. Why is this? Sprinting is really intense! So intense that your average athlete is going to perform worse in the weight room after a sufficiently potent sprint session on the track. One might say, “well the goal is to get fast, sprinters aren’t powerlifters.” If that is your position, then why lift at all? Just for shits and giggles? No. We lift to get stronger, more powerful, and more resilient. Enhancing these qualities (speed OR strength OR power OR fitness etc) is important, and I’d argue they’re important enough to have their own day of training dedicated to them from time to time.

Assumption #2 – Everybody needs to do X number of things in a given day of training.

Continuing onward, coaches and athletes often fall into the trap of mental constructs. What are mental constructs? These are the things we tell ourselves and convince ourselves of, despite them not being grounded in any absolute fact. Mental constructs are everywhere, and can make a major impact on your perspective depending on what you choose to believe.

One mental construct could be that you need to sprint and lift every day. Another might be that you need butter in your coffee. Another could be that you need 10,000 hours of doing something to become a master. These things may be good and true in certain circumstances, but they aren’t absolute fact.

In the context of sprint training, people tend to convince themselves that they need to do X amount of work, with Y amount of different stimuli, in order to get Z result. This is the mindset which breeds high volume running programs with endless injuries. This is the mindset which leads one to think that if they lift, they will get too bulky to perform well. This is also the mindset which convinces people to do two training sessions per day.

People often operate from a fear based perspective, in this case they operate by being motivated by the fear of failure. The coach or athlete fears failure, and compensates by trying to fit as much training stimuli into their program as possible, often to the point of detriment. In order to stuff your training program like a turkey on Thanksgiving with all the qualities you’ve convinced yourself you need to practice, you inherently will gravitate toward multiple training sessions.


Not all athletes have the same capacity for recovery.

Because of the individual nature of adaptation to training, the same amount of training will equate to a different level fatigue depending on the athlete. The glasses above represent 3 athletes in the same program, and the water itself represents their level of fatigue.

Athlete #1 on the left handles the training like a champ, barely feeling tired and coming back every day ready to attack training. Athlete #2 in the middle is definitely stressed by the workout, but with some quality nutrition and 9-10 hours of sleep, they will be OK to come back the next day. Then you have Athlete #3 on the right, who does the same training program as the other two athletes, but finds themselves at the limits of their capacity for training and recovery.

If you train once per day, you are unlikely to ever drive Athlete #3 into the frying pan of over-training. If instead you train twice a day Athlete #3 will be chronically over-trained. The question then becomes, do we cater our training to the few athletes who can handle a high load, at the expense of most athletes who cannot? This seems the case in a lot of track programs.

Assumption #3 – The pro’s do it, so I should too.

At first glance, its not horrible logic to try and emulate the world’s best athletes by training in a similar fashion. The factor left out from this line of thought is that the pros likely have advanced recovery methods available to them which you do not. Beyond that, they got to being elite because they are generally more capable than the average athlete. Between being more capable of recovering AND having access to enhanced recovery methods, it would be unwise to implement a pro’s program if you yourself aren’t going to be in the same position to optimally recover between sessions or days of training.

In a similar vein, you have to consider historical context. I have always been a big fan of Charlie Francis’ work, and think he was ahead of the curve with his training methods. Still, one must consider the fact that the details of his training (which was all about toggling between intense days of sprints/jumps/throws/lifts & low intensity days of tempo & circuits) are highly impacted by the nature of those times – big doses of drugs. While I think the effect of drugs on performance is over-rated, there is absolutely zero doubt that the capacity to handle high loads of training is enhanced by drug use.

Therefore, taking Johnny the twig and throwing him into a multi-session day with 4-6 high intensity types of training is not going to end well. Whether he’s chronically fatigued or chronically injured, he will one way or another see some negative effects if his training is not optimal for his capacity to train and recover. As I’ve stated in other articles, be sure that the model of you training is appropriate to the athletes you coach. If your training program is based off of Soviet methods or the CF system, and your athletes aren’t juiced to the gills, then you will be required to change something to ensure that they can recover. This change may be that most days should only be single session days.

Mixed training is non-specific, and non-specific training leads to non-specific adaptations.

The number of different stimuli and the subsequent specificity of adaptation are indirectly proportional. What do I mean by that? The more things you do in your day of training, the less specific your adaptations will be. If you sprint, jump, lift, ride the bike, and climb a mountain, how could you ever think that your body knows that your ultimate goal is to sprint faster? On the contrary, if you lift, jump, and sprint on separate days, you are much more likely to see specific adaptations to any given quality. Beyond that, your dose of training for each individual quality can be higher, due to the fact that its the only thing you’re working that day. Instead of cutting your speed session short and then having a sub-par lift because you’re tired, why not squeeze the sponge on your speed work, rest, and come back the next day to lift?


It is important that you avoid the common assumptions that people use to come to the conclusion that they should use multiple training sessions every day. Do not assume that all high intensity stressors will elicit the same or similar response from the body. Do not assume that you need to or can handle doing X number of things in a given day of training. Lastly, do not assume that you can do what the pro’s do (or what the Soviets did) and expect you can adapt effectively to those workloads.

I’m not here to tell you that you cannot train twice a day, or that doing so is never productive. What I am saying is that you should avoid the herd mentality, and truly ask yourself why you do what you do. Get into a few levels of asking yourself why, and you might find a gap in logic at some point (which was likely clouded by your attachment to your way of doing things).

The idea that you need to combine a bunch of different high intensity means into a multi-session day is a mental construct, not a law of nature. Whether you use this method of training or another, I implore you to question why you do it that way, and open yourself to ideas other than your own. There are too many coaches who continue to do the same things, see the same issue, and not make any change. Ultimately, we are all here to try and improve our own or someone else’s experience as an athlete. As such, we should always be open to improvement and changing our way of thinking or doing things.