Longevity Briefs: Is Strength Training As Good As Aerobic Exercise When It Comes To Longevity?

Getting your Trinity Audio player ready...

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

Exercise is a key pillar of longevity, but what type of exercise is most rewarding? Studies generally suggest that aerobic exercise correlates better with reduced mortality than resistance training and suffers from lower diminishing return. However, many of these studies are confounded by the complex relationship between exercise and other factors, not least of all steroid abuse among those undergoing resistance training. Resistance training is primarily aimed at stimulating muscle growth but can also be aerobically demanding, and thus has the potential to increase two metrics that are associated with large reductions in mortality: muscle strength and maximal oxygen consumption (VO2max). But is it aerobically demanding enough to ‘count’ as aerobic exercise? This study discusses that question.

The discovery:

Researchers recruited 22 men in their 20s and 30s, and performed tests to determine the heaviest weight they could squat for one repetition (the 1 repetition maximum or 1RM) and to determine their maximum rate of oxygen consumption (VO2max). After the participants were well rested, they performed 10 reps of squats for 5 sets at 65% of their 1RM.

They found that oxygen consumption of participants reached 92.2% of their VO2max when the highest rates of oxygen consumption during each set were averaged. For reference, running at 10km/h might get you up to around 80% of VO2max. In other words, these sets were very aerobically demanding. Indeed, those participants with the highest muscle strength actually achieved a rate of oxygen consumption that was higher than their previously measured maximum – at 108% VO2max. Also, when accounting for body mass and the fact that they were lifting more weight, the stronger participants still used more oxygen for the same relative intensity of exercise, suggesting that having more muscle mass might lead to higher relative oxygen consumption.

Rate of oxygen consumption per minute for each set among high strength, low strength and all participants (see key). The lines in the centre of each box represent median oxygen consumption or 50th percentile, which means 50% of participants in that group consumed less oxygen than that. The bottoms and tops of the boxes are the 25th and 75th percentiles. The ‘whiskers’ signify the maximum and minimum values in each group. The percentages refer to oxygen consumption as a percentage of the previously measured maximal oxygen consumption, VO2max.
*Cardiorespiratory and aerobic demands of squat exercise*

The implications:

So, it seems as though squats can be an excellent aerobic exercise, but there are some important catches to keep in mind. Firstly, the participants of this study all had experience with resistance training and were training with weights that allowed them to complete almost all of their sets. A previous study in which participants trained with 75% of their 1RM saw significantly lower levels of oxygen consumption. It is therefore likely that the specific training protocol is important for maximising the aerobic demands of the training session. Furthermore, the high levels of oxygen consumption observed here were not maintained for the entire duration of the session since participants were resting between sets. So while squats may be able to substitute conventional aerobic activity, they probably need to be done with shorter breaks and less weight than might be optimal for building strength.