If you are interested in weight training this is a good study to take some interest in. While teaching on personal training programme at my local college we got into a bit of a debate. If a repetition is based on tempo e.g. 3 seconds up/ 3 seconds down and for instance you do 10 repetitions (60 seconds time under tension) for a hypertrophy goal is it the same as performing 5 repetitions for 6 seconds up and 6 seconds (still 60 seconds time under tension) down if weight is controlled?
In fairness there are coaches who base their whole model of training on this concept so it is a good question to ask. I dug in to the research and found this study which pretty much performed the above but for slightly different repetitions and time under tension.
The paper suggests that training protocols conducted with the same time under tension, but with different configurations, produce distinct neuromuscular and metabolic responses so that performing higher repetition numbers with shorter repetition durations might be a more appropriate strategy to increase muscle activation and blood lactate concentration. Traditionally higher repetitions (plus 6) have always been favoured for muscular endurance and hypertrophy work but it does suggests that there may more favourable repetition ranges (higher) to work with submaximal weight if the goals are not predominantly strength orientated.