There are measurable differences in basal metabolic rates. However, 96% of the population is within 10-16% of the average and 68% of the population is within 6-8%. Therefore blaming your genetics for either being under- or overweight is ludicrous. The most extreme cases (under 5 percentile) showcase differences of 600kcal and the probability of that occurring between two random people are 0.5%.
We are varying in our basal metabolic rates, however the variances are usually low and attribute to nothing in our athletics and aesthetics. If it seems to you that gaining or losing weight is really hard for you for some reason I recommend calculating your total daily energy expenditure and simply write down everything you eat for a week (a month would be more beneficial) or insert those numbers to a smart phone app. I assure you that the numbers can be quite bewildering to most. If you naturally have a slow or fast metabolism then adding or retracting those 200kcals seems very easy once we truly know our intake.
Those variances do not affect recovery times. Those are attributed to many different factors like age, hours spend sleeping, active recoveries, vitamin and mineral intake, macronutrient distribution and intake, hormonal levels (heavily influenced by testosterone) – therefore also affected by genetics. Frequency of training sessions should be determined by our athletic background, time spend on active recovery and the nature of our training. If a lifting novice performs heavy compound lifts every single session, then it is recommended to provide enough time in-between to rest and recover. Our bodies adapt, albeit slowly, to the resistance and our recovery rates hasten. Professional athletes can train several times a day – although the nature of each session is different and can be categorized to heavy or light workouts – because not only have their bodies adapted form years of exercising but also because they get deep tissue massages, swim, spend time in saunas and cryogenic chambers. Foam rolling and stretching is a staple of many programs nowadays.
When determining your own frequency it is necessary to understand and listen to your body. Stalling and hitting a so-called plateau may mean that you are pushing your body too far and if your numbers are going backwards, then deloading and reassessing your program is paramount. Broader distribution of workouts can help, but if we are conscious about how our body recovers then by amplifying that recovery we can successfully up the frequency of training, steer clear of injury and therefore reach our goals faster.