TOOLBOX: Time off. Sometimes it’s essential and deliberately planned into our annual training schedule. Other times it’s forced upon us by work, family priorities, and even injury. While useful, breaks can bring out the fear of losing all of our carefully built fitness. What is the minimum dose of training that you need in order to maintain fitness?
The minimum dose of training
Taking a Break
Being an athlete often means that exercise is more than something that we do for sport or for fitness – exercise and fitness are wrapped up in our identity and self-worth. That makes taking time away both a physical and mental challenge.
We may need to take time away from exercise for many reasons. A period of greatly reduced activity or complete rest is a natural part of the annual training cycle, and can last from several days through to several weeks depending on time of the season, age, and fitness level. A busy professional life means that most athletes face training disruptions due to work demands and travel. Family life also means that we need to factor in family priorities such as holidays. Finally, there is the dreaded and unwelcome enforced breaks due to injury.
While time off has an important function and role in every training program, it can also be a physical and mental balancing act. Too much time off and the known physiological effects of detraining can set you back far enough that you may at most match your current season’s gains rather than building on and exceeding them. On the other hand, the real or perceived stress of taking time off means that many of us do not take breaks properly, doing too much or starting full training too early before we truly benefit physically and mentally from that break.
What is The Least I Can Get Away With?
This leads to an interesting and important question: what is the minimum dose of training that is required to maintain fitness during a break from focused training?
This minimum dose idea was the topic of a review by Spiering et al. (2021). Their review specifically tried to focus on physical performance measures (VO2max, muscle size and strength) rather than physiological (bone mineral density, insulin sensitivity, etc.) or training adaptations (e.g., flexibility). They also only reviewed studies with more than four weeks of reduced training, thus separating their work from tapering research which has a specific goal of enhancing competition readiness.
Reduced Training and Endurance Capacity
In the realm of endurance performance, the main data found came from a series of studies by RC Hickson in the early 1980s (Hickson and Rosenkoetter 1981; Hickson et al. 1982, 1985). These were logistically challenging studies with nearly six months of commitment by participants, and helps to explain why research in this field is so limited. Moderately active but previously untrained participants first performed aerobic training for 10 weeks (6 sessions a week of 40 minutes at 90-100% VO2max). Over the next 15 weeks, groups then reduced their frequency, duration, or intensity by either 33 or 66%.
- VO2max and endurance capacity at 100% VO2max did not decrease significantly from immediately post-training to 15 weeks afterwards with either a 33% (4 days/week) or even a 66% (2 days/week) training reduction.
- When volume was reduced by maintaining frequency at 6 sessions weekly but reducing duration of each session, both VO2max and endurance capacity at 100% VO2max were maintained.
- The efficacy from reducing intensity was mixed. Reducing intensity by 66% while maintaining both frequency and duration significantly reduced both VO2max and endurance capacity, while reducing intensity by 33% reduced VO2max but had no effect on endurance capacity at 100% VO2max.
Interestingly these findings with reducing training volume fit with the general consensus of tapering research, which emphasizes a major reduction in training volume while maintaining intensity.
Reduced Training and Muscle Adaptations
Compared to the above, there is a comparatively richer database of studies into how reduced training affects muscle adaptations to strength training. Paradoxically, this plethora of studies can make it more difficult to generalize, due to the wide variation in training/detraining protocols and also how muscle testing was performed or quantified. However, in general it appears that:
- Compared to a regular schedule of 2-3 strength training sessions, the minimum dose for maintaining muscle strength (1 repetition maximum or 1-RM) appears to be 1 session per week. In contrast, 1 session every two weeks led to a significant decline in squat 1-RM over 12 weeks.
- No study has directly isolated just duration or the number of sets within a strength session. However, with the few studies that reduced both frequency and the number of sets, the similar finding of one weekly session of a single set being sufficient to maintain strength seems to hold.
- Only one study was found where a reduction in intensity was isolated, finding that reducing workload to 50% of isometric maximal voluntary contraction was not sufficient to maintain muscle strength (Morehouse 1967).
Practically, if you are taking time away from strength training, it appears that a single set of exercises done once a week is sufficient to maintain most or all of your strength adaptations. However, this set should be done at full intensity, and therefore a thorough warmup is required to minimize injury risks.
Along with periods of enforced training reduction, this information on strength maintenance with reduced training is important to also keep in mind during the competitive season, when many of us tend to leave strength training aside in favour of more time on the bike.
So how might you put this information to use if you are on a weeklong work trip and all you have is access to a hotel gym? The good news is that you don’t have to dread slogging away for hours every day on an ill-fitting or uncomfortable gym bike. Instead, put polarized training aside in favour of a couple of short but intense sessions. Do a 30-45 minute ride or run featuring a warmup and 2-3 sets of Tabata style micro-intervals of 20-30 seconds with 15-30 s recovery. On one of these days, pair the high-intensity aerobic work with a single set of key multi-joint resistance exercises like leg extensions, bench presses, rows, and dumbbell lunges to maintain strength.
‘Cav’ resting at the track
Hickson R, Rosenkoetter M (1981) Reduced Training Frequencies and Maintenance of Increased Aerobic Power. Med Sci Sports Exerc 13:13–16
Hickson RC, Foster C, Pollock ML, et al (1985) Reduced training intensities and loss of aerobic power, endurance, and cardiac growth. J Appl Physiol 58:492–499. https://doi.org/10.1152/jappl.1918.104.22.1682
Hickson RC, Kanakis C, Davis JR, et al (1982) Reduced training duration effects on aerobic power, endurance, and cardiac growth. J Appl Physiol 53:225–229. https://doi.org/10.1152/jappl.1922.214.171.124
Morehouse C (1967) Development and Maintenance of Isometric Strength of Subjects with Diverse Initial Strengths. Res Q 38:449–456. https://doi.org/10.1080/10671188.1967.10613414
Spiering BA, Mujika I, Sharp MA, Foulis SA (2021) Maintaining Physical Performance: The Minimal Dose of Exercise Needed to Preserve Endurance and Strength Over Time. J Strength Cond Res 35:1449–1458. https://doi.org/10.1519/JSC.0000000000003964